Merge branch 'master' into override-now-func-on-db-instance

2019-06-10 20:42:18 +08:00 · 2019-06-10 20:42:18 +08:00 · 5c9ba54b65
commit 5c9ba54b65
parent eaffac2625 af01854d3e
31 changed files with 821 additions and 134 deletions
--- a/.codeclimate.yml
+++ b/.codeclimate.yml
@ -1,11 +0,0 @@
---
-engines:
-  gofmt:
-    enabled: true
-  govet:
-    enabled: true
-  golint:
-    enabled: true
-ratings:
-  paths:
-  - "**.go"
--- a/.gitignore
+++ b/.gitignore
@ -1,2 +1,3 @@
 documents
+coverage.txt
 _book
--- a/README.md
+++ b/README.md
@ -4,10 +4,11 @@ The fantastic ORM library for Golang, aims to be developer friendly.

 [![go report card](https://goreportcard.com/badge/github.com/jinzhu/gorm "go report card")](https://goreportcard.com/report/github.com/jinzhu/gorm)
 [![wercker status](https://app.wercker.com/status/8596cace912c9947dd9c8542ecc8cb8b/s/master "wercker status")](https://app.wercker.com/project/byKey/8596cace912c9947dd9c8542ecc8cb8b)
+[![codecov](https://codecov.io/gh/jinzhu/gorm/branch/master/graph/badge.svg)](https://codecov.io/gh/jinzhu/gorm)
 [![Join the chat at https://gitter.im/jinzhu/gorm](https://img.shields.io/gitter/room/jinzhu/gorm.svg)](https://gitter.im/jinzhu/gorm?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Open Collective Backer](https://opencollective.com/gorm/tiers/backer/badge.svg?label=backer&color=brightgreen "Open Collective Backer")](https://opencollective.com/gorm)
 [![Open Collective Sponsor](https://opencollective.com/gorm/tiers/sponsor/badge.svg?label=sponsor&color=brightgreen "Open Collective Sponsor")](https://opencollective.com/gorm)
-[![MIT license](http://img.shields.io/badge/license-MIT-brightgreen.svg)](http://opensource.org/licenses/MIT)
+[![MIT license](https://img.shields.io/badge/license-MIT-brightgreen.svg)](https://opensource.org/licenses/MIT)
 [![GoDoc](https://godoc.org/github.com/jinzhu/gorm?status.svg)](https://godoc.org/github.com/jinzhu/gorm)

 ## Overview
@ -27,11 +28,11 @@ The fantastic ORM library for Golang, aims to be developer friendly.

 ## Getting Started

-* GORM Guides [http://gorm.io](http://gorm.io)
+* GORM Guides [https://gorm.io](https://gorm.io)

 ## Contributing

-[You can help to deliver a better GORM, check out things you can do](http://gorm.io/contribute.html)
+[You can help to deliver a better GORM, check out things you can do](https://gorm.io/contribute.html)

 ## License

--- a/association.go
+++ b/association.go
@ -368,6 +368,7 @@ func (association *Association) saveAssociations(values ...interface{}) *Associa
 	return association
 }

+// setErr set error when the error is not nil. And return Association.
 func (association *Association) setErr(err error) *Association {
 	if err != nil {
 		association.Error = err
--- a/callback.go
+++ b/callback.go
@ -1,6 +1,6 @@
 package gorm

-import "log"
+import "fmt"

 // DefaultCallback default callbacks defined by gorm
 var DefaultCallback = &Callback{}
@ -13,6 +13,7 @@ var DefaultCallback = &Callback{}
 //   Field `rowQueries` contains callbacks will be call when querying object with Row, Rows...
 //   Field `processors` contains all callback processors, will be used to generate above callbacks in order
 type Callback struct {
+	logger     logger
 	creates    []*func(scope *Scope)
 	updates    []*func(scope *Scope)
 	deletes    []*func(scope *Scope)
@ -23,6 +24,7 @@ type Callback struct {

 // CallbackProcessor contains callback informations
 type CallbackProcessor struct {
+	logger    logger
 	name      string              // current callback's name
 	before    string              // register current callback before a callback
 	after     string              // register current callback after a callback
@ -33,8 +35,9 @@ type CallbackProcessor struct {
 	parent    *Callback
 }

-func (c *Callback) clone() *Callback {
+func (c *Callback) clone(logger logger) *Callback {
 	return &Callback{
+		logger:     logger,
 		creates:    c.creates,
 		updates:    c.updates,
 		deletes:    c.deletes,
@ -53,28 +56,28 @@ func (c *Callback) clone() *Callback {
 //       scope.Err(errors.New("error"))
 //     })
 func (c *Callback) Create() *CallbackProcessor {
-	return &CallbackProcessor{kind: "create", parent: c}
+	return &CallbackProcessor{logger: c.logger, kind: "create", parent: c}
 }

 // Update could be used to register callbacks for updating object, refer `Create` for usage
 func (c *Callback) Update() *CallbackProcessor {
-	return &CallbackProcessor{kind: "update", parent: c}
+	return &CallbackProcessor{logger: c.logger, kind: "update", parent: c}
 }

 // Delete could be used to register callbacks for deleting object, refer `Create` for usage
 func (c *Callback) Delete() *CallbackProcessor {
-	return &CallbackProcessor{kind: "delete", parent: c}
+	return &CallbackProcessor{logger: c.logger, kind: "delete", parent: c}
 }

 // Query could be used to register callbacks for querying objects with query methods like `Find`, `First`, `Related`, `Association`...
 // Refer `Create` for usage
 func (c *Callback) Query() *CallbackProcessor {
-	return &CallbackProcessor{kind: "query", parent: c}
+	return &CallbackProcessor{logger: c.logger, kind: "query", parent: c}
 }

 // RowQuery could be used to register callbacks for querying objects with `Row`, `Rows`, refer `Create` for usage
 func (c *Callback) RowQuery() *CallbackProcessor {
-	return &CallbackProcessor{kind: "row_query", parent: c}
+	return &CallbackProcessor{logger: c.logger, kind: "row_query", parent: c}
 }

 // After insert a new callback after callback `callbackName`, refer `Callbacks.Create`
@ -93,7 +96,7 @@ func (cp *CallbackProcessor) Before(callbackName string) *CallbackProcessor {
 func (cp *CallbackProcessor) Register(callbackName string, callback func(scope *Scope)) {
 	if cp.kind == "row_query" {
 		if cp.before == "" && cp.after == "" && callbackName != "gorm:row_query" {
-			log.Printf("Registing RowQuery callback %v without specify order with Before(), After(), applying Before('gorm:row_query') by default for compatibility...\n", callbackName)
+			cp.logger.Print(fmt.Sprintf("Registering RowQuery callback %v without specify order with Before(), After(), applying Before('gorm:row_query') by default for compatibility...\n", callbackName))
 			cp.before = "gorm:row_query"
 		}
 	}
@ -107,7 +110,7 @@ func (cp *CallbackProcessor) Register(callbackName string, callback func(scope *
 // Remove a registered callback
 //     db.Callback().Create().Remove("gorm:update_time_stamp_when_create")
 func (cp *CallbackProcessor) Remove(callbackName string) {
-	log.Printf("[info] removing callback `%v` from %v\n", callbackName, fileWithLineNum())
+	cp.logger.Print(fmt.Sprintf("[info] removing callback `%v` from %v\n", callbackName, fileWithLineNum()))
 	cp.name = callbackName
 	cp.remove = true
 	cp.parent.processors = append(cp.parent.processors, cp)
@ -120,7 +123,7 @@ func (cp *CallbackProcessor) Remove(callbackName string) {
 //		   scope.SetColumn("Updated", now)
 //     })
 func (cp *CallbackProcessor) Replace(callbackName string, callback func(scope *Scope)) {
-	log.Printf("[info] replacing callback `%v` from %v\n", callbackName, fileWithLineNum())
+	cp.logger.Print(fmt.Sprintf("[info] replacing callback `%v` from %v\n", callbackName, fileWithLineNum()))
 	cp.name = callbackName
 	cp.processor = &callback
 	cp.replace = true
@ -159,7 +162,7 @@ func sortProcessors(cps []*CallbackProcessor) []*func(scope *Scope) {
 	for _, cp := range cps {
 		// show warning message the callback name already exists
 		if index := getRIndex(allNames, cp.name); index > -1 && !cp.replace && !cp.remove {
-			log.Printf("[warning] duplicated callback `%v` from %v\n", cp.name, fileWithLineNum())
+			cp.logger.Print(fmt.Sprintf("[warning] duplicated callback `%v` from %v\n", cp.name, fileWithLineNum()))
 		}
 		allNames = append(allNames, cp.name)
 	}
--- a/callback_create.go
+++ b/callback_create.go
@ -83,11 +83,18 @@ func createCallback(scope *Scope) {
 			quotedTableName = scope.QuotedTableName()
 			primaryField    = scope.PrimaryField()
 			extraOption     string
+			insertModifier  string
 		)

 		if str, ok := scope.Get("gorm:insert_option"); ok {
 			extraOption = fmt.Sprint(str)
 		}
+		if str, ok := scope.Get("gorm:insert_modifier"); ok {
+			insertModifier = strings.ToUpper(fmt.Sprint(str))
+			if insertModifier == "INTO" {
+				insertModifier = ""
+			}
+		}

 		if primaryField != nil {
 			returningColumn = scope.Quote(primaryField.DBName)
@ -97,7 +104,8 @@ func createCallback(scope *Scope) {

 		if len(columns) == 0 {
 			scope.Raw(fmt.Sprintf(
-				"INSERT INTO %v %v%v%v",
+				"INSERT %v INTO %v %v%v%v",
+				addExtraSpaceIfExist(insertModifier),
 				quotedTableName,
 				scope.Dialect().DefaultValueStr(),
 				addExtraSpaceIfExist(extraOption),
@ -105,7 +113,8 @@ func createCallback(scope *Scope) {
 			))
 		} else {
 			scope.Raw(fmt.Sprintf(
-				"INSERT INTO %v (%v) VALUES (%v)%v%v",
+				"INSERT %v INTO %v (%v) VALUES (%v)%v%v",
+				addExtraSpaceIfExist(insertModifier),
 				scope.QuotedTableName(),
 				strings.Join(columns, ","),
 				strings.Join(placeholders, ","),
--- a/callback_query_preload.go
+++ b/callback_query_preload.go
@ -391,14 +391,20 @@ func (scope *Scope) handleManyToManyPreload(field *Field, conditions []interface
 		key := toString(getValueFromFields(indirectScopeValue, foreignFieldNames))
 		fieldsSourceMap[key] = append(fieldsSourceMap[key], indirectScopeValue.FieldByName(field.Name))
 	}
-	for source, link := range linkHash {
-		for i, field := range fieldsSourceMap[source] {
+
+	for source, fields := range fieldsSourceMap {
+		for _, f := range fields {
 			//If not 0 this means Value is a pointer and we already added preloaded models to it
-			if fieldsSourceMap[source][i].Len() != 0 {
+			if f.Len() != 0 {
 				continue
 			}
-			field.Set(reflect.Append(fieldsSourceMap[source][i], link...))
-		}

+			v := reflect.MakeSlice(f.Type(), 0, 0)
+			if len(linkHash[source]) > 0 {
+				v = reflect.Append(f, linkHash[source]...)
+			}
+
+			f.Set(v)
+		}
 	}
 }
--- a/callback_row_query.go
+++ b/callback_row_query.go
@ -1,6 +1,9 @@
 package gorm

-import "database/sql"
+import (
+	"database/sql"
+	"fmt"
+)

 // Define callbacks for row query
 func init() {
@ -20,6 +23,9 @@ type RowsQueryResult struct {
 func rowQueryCallback(scope *Scope) {
 	if result, ok := scope.InstanceGet("row_query_result"); ok {
 		scope.prepareQuerySQL()
+		if str, ok := scope.Get("gorm:query_option"); ok {
+			scope.SQL += addExtraSpaceIfExist(fmt.Sprint(str))
+		}

 		if rowResult, ok := result.(*RowQueryResult); ok {
 			rowResult.Row = scope.SQLDB().QueryRow(scope.SQL, scope.SQLVars...)
--- a/callback_system_test.go
+++ b/callback_system_test.go
@ -23,7 +23,7 @@ func afterCreate1(s *Scope)  {}
 func afterCreate2(s *Scope)  {}

 func TestRegisterCallback(t *testing.T) {
-	var callback = &Callback{}
+	var callback = &Callback{logger: defaultLogger}

 	callback.Create().Register("before_create1", beforeCreate1)
 	callback.Create().Register("before_create2", beforeCreate2)
@ -37,7 +37,7 @@ func TestRegisterCallback(t *testing.T) {
 }

 func TestRegisterCallbackWithOrder(t *testing.T) {
-	var callback1 = &Callback{}
+	var callback1 = &Callback{logger: defaultLogger}
 	callback1.Create().Register("before_create1", beforeCreate1)
 	callback1.Create().Register("create", create)
 	callback1.Create().Register("after_create1", afterCreate1)
@ -46,7 +46,7 @@ func TestRegisterCallbackWithOrder(t *testing.T) {
 		t.Errorf("register callback with order")
 	}

-	var callback2 = &Callback{}
+	var callback2 = &Callback{logger: defaultLogger}

 	callback2.Update().Register("create", create)
 	callback2.Update().Before("create").Register("before_create1", beforeCreate1)
@ -60,7 +60,7 @@ func TestRegisterCallbackWithOrder(t *testing.T) {
 }

 func TestRegisterCallbackWithComplexOrder(t *testing.T) {
-	var callback1 = &Callback{}
+	var callback1 = &Callback{logger: defaultLogger}

 	callback1.Query().Before("after_create1").After("before_create1").Register("create", create)
 	callback1.Query().Register("before_create1", beforeCreate1)
@ -70,7 +70,7 @@ func TestRegisterCallbackWithComplexOrder(t *testing.T) {
 		t.Errorf("register callback with order")
 	}

-	var callback2 = &Callback{}
+	var callback2 = &Callback{logger: defaultLogger}

 	callback2.Delete().Before("after_create1").After("before_create1").Register("create", create)
 	callback2.Delete().Before("create").Register("before_create1", beforeCreate1)
@ -86,7 +86,7 @@ func TestRegisterCallbackWithComplexOrder(t *testing.T) {
 func replaceCreate(s *Scope) {}

 func TestReplaceCallback(t *testing.T) {
-	var callback = &Callback{}
+	var callback = &Callback{logger: defaultLogger}

 	callback.Create().Before("after_create1").After("before_create1").Register("create", create)
 	callback.Create().Register("before_create1", beforeCreate1)
@ -99,7 +99,7 @@ func TestReplaceCallback(t *testing.T) {
 }

 func TestRemoveCallback(t *testing.T) {
-	var callback = &Callback{}
+	var callback = &Callback{logger: defaultLogger}

 	callback.Create().Before("after_create1").After("before_create1").Register("create", create)
 	callback.Create().Register("before_create1", beforeCreate1)
--- a/callback_update.go
+++ b/callback_update.go
@ -75,7 +75,7 @@ func updateCallback(scope *Scope) {
 		} else {
 			for _, field := range scope.Fields() {
 				if scope.changeableField(field) {
-					if !field.IsPrimaryKey && field.IsNormal {
+					if !field.IsPrimaryKey && field.IsNormal && (field.Name != "CreatedAt" || !field.IsBlank) {
 						if !field.IsForeignKey || !field.IsBlank || !field.HasDefaultValue {
 							sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(field.DBName), scope.AddToVars(field.Field.Interface())))
 						}
--- a/create_test.go
+++ b/create_test.go
@ -269,3 +269,20 @@ func TestOmitWithCreate(t *testing.T) {
 		t.Errorf("Should not create omitted relationships")
 	}
 }
+
+func TestCreateIgnore(t *testing.T) {
+	float := 35.03554004971999
+	now := time.Now()
+	user := User{Name: "CreateUser", Age: 18, Birthday: &now, UserNum: Num(111), PasswordHash: []byte{'f', 'a', 'k', '4'}, Latitude: float}
+
+	if !DB.NewRecord(user) || !DB.NewRecord(&user) {
+		t.Error("User should be new record before create")
+	}
+
+	if count := DB.Create(&user).RowsAffected; count != 1 {
+		t.Error("There should be one record be affected when create record")
+	}
+	if DB.Dialect().GetName() == "mysql" && DB.Set("gorm:insert_modifier", "IGNORE").Create(&user).Error != nil {
+		t.Error("Should ignore duplicate user insert by insert modifier:IGNORE ")
+	}
+}
--- a/customize_column_test.go
+++ b/customize_column_test.go
@ -289,6 +289,9 @@ type SelfReferencingUser struct {
 func TestSelfReferencingMany2ManyColumn(t *testing.T) {
 	DB.DropTable(&SelfReferencingUser{}, "UserFriends")
 	DB.AutoMigrate(&SelfReferencingUser{})
+	if !DB.HasTable("UserFriends") {
+		t.Errorf("auto migrate error, table UserFriends should be created")
+	}

 	friend1 := SelfReferencingUser{Name: "friend1_m2m"}
 	if err := DB.Create(&friend1).Error; err != nil {
@ -313,6 +316,14 @@ func TestSelfReferencingMany2ManyColumn(t *testing.T) {
 		t.Errorf("Should find created friends correctly")
 	}

+	var count int
+	if err := DB.Table("UserFriends").Count(&count).Error; err != nil {
+		t.Errorf("no error should happen, but got %v", err)
+	}
+	if count == 0 {
+		t.Errorf("table UserFriends should have records")
+	}
+
 	var newUser = SelfReferencingUser{}

 	if err := DB.Preload("Friends").First(&newUser, "id = ?", user.ID).Error; err != nil {
--- a/dialect.go
+++ b/dialect.go
@ -48,6 +48,9 @@ type Dialect interface {
 	// BuildKeyName returns a valid key name (foreign key, index key) for the given table, field and reference
 	BuildKeyName(kind, tableName string, fields ...string) string

+	// NormalizeIndexAndColumn returns valid index name and column name depending on each dialect
+	NormalizeIndexAndColumn(indexName, columnName string) (string, string)
+
 	// CurrentDatabase return current database name
 	CurrentDatabase() string
 }
@ -126,6 +129,10 @@ var ParseFieldStructForDialect = func(field *StructField, dialect Dialect) (fiel
 		additionalType = additionalType + " DEFAULT " + value
 	}

+	if value, ok := field.TagSettingsGet("COMMENT"); ok {
+		additionalType = additionalType + " COMMENT " + value
+	}
+
 	return fieldValue, dataType, size, strings.TrimSpace(additionalType)
 }

--- a/dialect_common.go
+++ b/dialect_common.go
@ -9,6 +9,8 @@ import (
 	"time"
 )

+var keyNameRegex = regexp.MustCompile("[^a-zA-Z0-9]+")
+
 // DefaultForeignKeyNamer contains the default foreign key name generator method
 type DefaultForeignKeyNamer struct {
 }
@ -166,10 +168,15 @@ func (commonDialect) DefaultValueStr() string {
 // BuildKeyName returns a valid key name (foreign key, index key) for the given table, field and reference
 func (DefaultForeignKeyNamer) BuildKeyName(kind, tableName string, fields ...string) string {
 	keyName := fmt.Sprintf("%s_%s_%s", kind, tableName, strings.Join(fields, "_"))
-	keyName = regexp.MustCompile("[^a-zA-Z0-9]+").ReplaceAllString(keyName, "_")
+	keyName = keyNameRegex.ReplaceAllString(keyName, "_")
 	return keyName
 }

+// NormalizeIndexAndColumn returns argument's index name and column name without doing anything
+func (commonDialect) NormalizeIndexAndColumn(indexName, columnName string) (string, string) {
+	return indexName, columnName
+}
+
 // IsByteArrayOrSlice returns true of the reflected value is an array or slice
 func IsByteArrayOrSlice(value reflect.Value) bool {
 	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))
--- a/dialect_mysql.go
+++ b/dialect_mysql.go
@ -11,6 +11,8 @@ import (
 	"unicode/utf8"
 )

+var mysqlIndexRegex = regexp.MustCompile(`^(.+)\((\d+)\)$`)
+
 type mysql struct {
 	commonDialect
 }
@ -100,7 +102,7 @@ func (s *mysql) DataTypeOf(field *StructField) string {
 					precision = fmt.Sprintf("(%s)", p)
 				}

-				if _, ok := field.TagSettingsGet("NOT NULL"); ok {
+				if _, ok := field.TagSettingsGet("NOT NULL"); ok || field.IsPrimaryKey {
 					sqlType = fmt.Sprintf("timestamp%v", precision)
 				} else {
 					sqlType = fmt.Sprintf("timestamp%v NULL", precision)
@ -178,7 +180,7 @@ func (s mysql) BuildKeyName(kind, tableName string, fields ...string) string {
 	bs := h.Sum(nil)

 	// sha1 is 40 characters, keep first 24 characters of destination
-	destRunes := []rune(regexp.MustCompile("[^a-zA-Z0-9]+").ReplaceAllString(fields[0], "_"))
+	destRunes := []rune(keyNameRegex.ReplaceAllString(fields[0], "_"))
 	if len(destRunes) > 24 {
 		destRunes = destRunes[:24]
 	}
@ -186,6 +188,17 @@ func (s mysql) BuildKeyName(kind, tableName string, fields ...string) string {
 	return fmt.Sprintf("%s%x", string(destRunes), bs)
 }

+// NormalizeIndexAndColumn returns index name and column name for specify an index prefix length if needed
+func (mysql) NormalizeIndexAndColumn(indexName, columnName string) (string, string) {
+	submatch := mysqlIndexRegex.FindStringSubmatch(indexName)
+	if len(submatch) != 3 {
+		return indexName, columnName
+	}
+	indexName = submatch[1]
+	columnName = fmt.Sprintf("%s(%s)", columnName, submatch[2])
+	return indexName, columnName
+}
+
 func (mysql) DefaultValueStr() string {
 	return "VALUES()"
 }
--- a/dialects/mssql/mssql.go
+++ b/dialects/mssql/mssql.go
@ -198,6 +198,11 @@ func (mssql) DefaultValueStr() string {
 	return "DEFAULT VALUES"
 }

+// NormalizeIndexAndColumn returns argument's index name and column name without doing anything
+func (mssql) NormalizeIndexAndColumn(indexName, columnName string) (string, string) {
+	return indexName, columnName
+}
+
 func currentDatabaseAndTable(dialect gorm.Dialect, tableName string) (string, string) {
 	if strings.Contains(tableName, ".") {
 		splitStrings := strings.SplitN(tableName, ".", 2)
--- a/errors.go
+++ b/errors.go
@ -6,11 +6,11 @@ import (
 )

 var (
-	// ErrRecordNotFound record not found error, happens when only haven't find any matched data when looking up with a struct, finding a slice won't return this error
+	// ErrRecordNotFound returns a "record not found error". Occurs only when attempting to query the database with a struct; querying with a slice won't return this error
 	ErrRecordNotFound = errors.New("record not found")
-	// ErrInvalidSQL invalid SQL error, happens when you passed invalid SQL
+	// ErrInvalidSQL occurs when you attempt a query with invalid SQL
 	ErrInvalidSQL = errors.New("invalid SQL")
-	// ErrInvalidTransaction invalid transaction when you are trying to `Commit` or `Rollback`
+	// ErrInvalidTransaction occurs when you are trying to `Commit` or `Rollback`
 	ErrInvalidTransaction = errors.New("no valid transaction")
 	// ErrCantStartTransaction can't start transaction when you are trying to start one with `Begin`
 	ErrCantStartTransaction = errors.New("can't start transaction")
@ -21,7 +21,7 @@ var (
 // Errors contains all happened errors
 type Errors []error

-// IsRecordNotFoundError returns current error has record not found error or not
+// IsRecordNotFoundError returns true if error contains a RecordNotFound error
 func IsRecordNotFoundError(err error) bool {
 	if errs, ok := err.(Errors); ok {
 		for _, err := range errs {
@ -33,12 +33,12 @@ func IsRecordNotFoundError(err error) bool {
 	return err == ErrRecordNotFound
 }

-// GetErrors gets all happened errors
+// GetErrors gets all errors that have occurred and returns a slice of errors (Error type)
 func (errs Errors) GetErrors() []error {
 	return errs
 }

-// Add adds an error
+// Add adds an error to a given slice of errors
 func (errs Errors) Add(newErrors ...error) Errors {
 	for _, err := range newErrors {
 		if err == nil {
@ -62,7 +62,7 @@ func (errs Errors) Add(newErrors ...error) Errors {
 	return errs
 }

-// Error format happened errors
+// Error takes a slice of all errors that have occurred and returns it as a formatted string
 func (errs Errors) Error() string {
 	var errors = []string{}
 	for _, e := range errs {
--- a/field.go
+++ b/field.go
@ -2,6 +2,7 @@ package gorm

 import (
 	"database/sql"
+	"database/sql/driver"
 	"errors"
 	"fmt"
 	"reflect"
@ -44,7 +45,14 @@ func (field *Field) Set(value interface{}) (err error) {
 			if reflectValue.Type().ConvertibleTo(fieldValue.Type()) {
 				fieldValue.Set(reflectValue.Convert(fieldValue.Type()))
 			} else if scanner, ok := fieldValue.Addr().Interface().(sql.Scanner); ok {
-				err = scanner.Scan(reflectValue.Interface())
+				v := reflectValue.Interface()
+				if valuer, ok := v.(driver.Valuer); ok {
+					if v, err = valuer.Value(); err == nil {
+						err = scanner.Scan(v)
+					}
+				} else {
+					err = scanner.Scan(v)
+				}
 			} else {
 				err = fmt.Errorf("could not convert argument of field %s from %s to %s", field.Name, reflectValue.Type(), fieldValue.Type())
 			}
--- a/field_test.go
+++ b/field_test.go
@ -1,6 +1,9 @@
 package gorm_test

 import (
+	"database/sql/driver"
+	"encoding/hex"
+	"fmt"
 	"testing"

 	"github.com/jinzhu/gorm"
@ -47,3 +50,81 @@ func TestCalculateField(t *testing.T) {
 		t.Errorf("should find embedded field's tag settings")
 	}
 }
+
+type UUID [16]byte
+
+type NullUUID struct {
+	UUID
+	Valid bool
+}
+
+func FromString(input string) (u UUID) {
+	src := []byte(input)
+	return FromBytes(src)
+}
+
+func FromBytes(src []byte) (u UUID) {
+	dst := u[:]
+	hex.Decode(dst[0:4], src[0:8])
+	hex.Decode(dst[4:6], src[9:13])
+	hex.Decode(dst[6:8], src[14:18])
+	hex.Decode(dst[8:10], src[19:23])
+	hex.Decode(dst[10:], src[24:])
+	return
+}
+
+func (u UUID) String() string {
+	buf := make([]byte, 36)
+	src := u[:]
+	hex.Encode(buf[0:8], src[0:4])
+	buf[8] = '-'
+	hex.Encode(buf[9:13], src[4:6])
+	buf[13] = '-'
+	hex.Encode(buf[14:18], src[6:8])
+	buf[18] = '-'
+	hex.Encode(buf[19:23], src[8:10])
+	buf[23] = '-'
+	hex.Encode(buf[24:], src[10:])
+	return string(buf)
+}
+
+func (u UUID) Value() (driver.Value, error) {
+	return u.String(), nil
+}
+
+func (u *UUID) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case UUID: // support gorm convert from UUID to NullUUID
+		*u = src
+		return nil
+	case []byte:
+		*u = FromBytes(src)
+		return nil
+	case string:
+		*u = FromString(src)
+		return nil
+	}
+	return fmt.Errorf("uuid: cannot convert %T to UUID", src)
+}
+
+func (u *NullUUID) Scan(src interface{}) error {
+	u.Valid = true
+	return u.UUID.Scan(src)
+}
+
+func TestFieldSet(t *testing.T) {
+	type TestFieldSetNullUUID struct {
+		NullUUID NullUUID
+	}
+	scope := DB.NewScope(&TestFieldSetNullUUID{})
+	field := scope.Fields()[0]
+	err := field.Set(FromString("3034d44a-da03-11e8-b366-4a00070b9f00"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if id, ok := field.Field.Addr().Interface().(*NullUUID); !ok {
+		t.Fatal()
+	} else if !id.Valid || id.UUID.String() != "3034d44a-da03-11e8-b366-4a00070b9f00" {
+		t.Fatal(id)
+	}
+}
--- a/go.mod
+++ b/go.mod
@ -0,0 +1,11 @@
+module github.com/jinzhu/gorm
+
+require (
+	github.com/denisenkom/go-mssqldb v0.0.0-20190423183735-731ef375ac02
+	github.com/erikstmartin/go-testdb v0.0.0-20160219214506-8d10e4a1bae5
+	github.com/go-sql-driver/mysql v1.4.1
+	github.com/jinzhu/inflection v0.0.0-20180308033659-04140366298a
+	github.com/jinzhu/now v1.0.0
+	github.com/lib/pq v1.1.0
+	github.com/mattn/go-sqlite3 v1.10.0
+)
--- a/go.sum
+++ b/go.sum
@ -0,0 +1,134 @@
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+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/tools v0.0.0-20180828015842-6cd1fcedba52/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
+golang.org/x/tools v0.0.0-20190312170243-e65039ee4138/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+google.golang.org/api v0.3.1/go.mod h1:6wY9I6uQWHQ8EM57III9mq/AjF+i8G65rmVagqKMtkk=
+google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/appengine v1.5.0 h1:KxkO13IPW4Lslp2bz+KHP2E3gtFlrIGNThxkZQ3g+4c=
+google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/genproto v0.0.0-20190404172233-64821d5d2107/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/grpc v1.17.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
+google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
+google.golang.org/grpc v1.20.1 h1:Hz2g2wirWK7H0qIIhGIqRGTuMwTE8HEKFnDZZ7lm9NU=
+google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
--- a/interface.go
+++ b/interface.go
@ -1,6 +1,9 @@
 package gorm

-import "database/sql"
+import (
+	"context"
+	"database/sql"
+)

 // SQLCommon is the minimal database connection functionality gorm requires.  Implemented by *sql.DB.
 type SQLCommon interface {
@ -12,6 +15,7 @@ type SQLCommon interface {

 type sqlDb interface {
 	Begin() (*sql.Tx, error)
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
 }

 type sqlTx interface {
--- a/logger.go
+++ b/logger.go
@ -63,7 +63,12 @@ var LogFormatter = func(values ...interface{}) (messages []interface{}) {
 							formattedValues = append(formattedValues, "NULL")
 						}
 					} else {
-						formattedValues = append(formattedValues, fmt.Sprintf("'%v'", value))
+						switch value.(type) {
+						case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64, bool:
+							formattedValues = append(formattedValues, fmt.Sprintf("%v", value))
+						default:
+							formattedValues = append(formattedValues, fmt.Sprintf("'%v'", value))
+						}
 					}
 				} else {
 					formattedValues = append(formattedValues, "NULL")
--- a/main.go
+++ b/main.go
@ -1,6 +1,7 @@
 package gorm

 import (
+	"context"
 	"database/sql"
 	"errors"
 	"fmt"
@ -12,6 +13,7 @@ import (

 // DB contains information for current db connection
 type DB struct {
+	sync.RWMutex
 	Value        interface{}
 	Error        error
 	RowsAffected int64
@ -19,7 +21,7 @@ type DB struct {
 	// single db
 	db                SQLCommon
 	blockGlobalUpdate bool
-	logMode           int
+	logMode           logModeValue
 	logger            logger
 	search            *search
 	values            sync.Map
@ -34,6 +36,14 @@ type DB struct {
 	nowFuncOverride func() time.Time
 }

+type logModeValue int
+
+const (
+	defaultLogMode logModeValue = iota
+	noLogMode
+	detailedLogMode
+)
+
 // Open initialize a new db connection, need to import driver first, e.g:
 //
 //     import _ "github.com/go-sql-driver/mysql"
@ -132,7 +142,7 @@ func (s *DB) Dialect() Dialect {
 //     db.Callback().Create().Register("update_created_at", updateCreated)
 // Refer https://jinzhu.github.io/gorm/development.html#callbacks
 func (s *DB) Callback() *Callback {
-	s.parent.callbacks = s.parent.callbacks.clone()
+	s.parent.callbacks = s.parent.callbacks.clone(s.logger)
 	return s.parent.callbacks
 }

@ -144,9 +154,9 @@ func (s *DB) SetLogger(log logger) {
 // LogMode set log mode, `true` for detailed logs, `false` for no log, default, will only print error logs
 func (s *DB) LogMode(enable bool) *DB {
 	if enable {
-		s.logMode = 2
+		s.logMode = detailedLogMode
 	} else {
-		s.logMode = 1
+		s.logMode = noLogMode
 	}
 	return s
 }
@ -181,7 +191,8 @@ func (s *DB) HasBlockGlobalUpdate() bool {

 // SingularTable use singular table by default
 func (s *DB) SingularTable(enable bool) {
-	modelStructsMap = sync.Map{}
+	s.parent.Lock()
+	defer s.parent.Unlock()
 	s.parent.singularTable = enable
 }

@ -189,7 +200,13 @@ func (s *DB) SingularTable(enable bool) {
 func (s *DB) NewScope(value interface{}) *Scope {
 	dbClone := s.clone()
 	dbClone.Value = value
-	return &Scope{db: dbClone, Search: dbClone.search.clone(), Value: value}
+	scope := &Scope{db: dbClone, Value: value}
+	if s.search != nil {
+		scope.Search = s.search.clone()
+	} else {
+		scope.Search = &search{}
+	}
+	return scope
 }

 // QueryExpr returns the query as expr object
@ -309,6 +326,7 @@ func (s *DB) Assign(attrs ...interface{}) *DB {
 func (s *DB) First(out interface{}, where ...interface{}) *DB {
 	newScope := s.NewScope(out)
 	newScope.Search.Limit(1)
+
 	return newScope.Set("gorm:order_by_primary_key", "ASC").
 		inlineCondition(where...).callCallbacks(s.parent.callbacks.queries).db
 }
@ -505,11 +523,16 @@ func (s *DB) Debug() *DB {
 	return s.clone().LogMode(true)
 }

-// Begin begin a transaction
+// Begin begins a transaction
 func (s *DB) Begin() *DB {
+	return s.BeginTx(context.Background(), &sql.TxOptions{})
+}
+
+// BeginTX begins a transaction with options
+func (s *DB) BeginTx(ctx context.Context, opts *sql.TxOptions) *DB {
 	c := s.clone()
 	if db, ok := c.db.(sqlDb); ok && db != nil {
-		tx, err := db.Begin()
+		tx, err := db.BeginTx(ctx, opts)
 		c.db = interface{}(tx).(SQLCommon)

 		c.dialect.SetDB(c.db)
@ -535,7 +558,26 @@ func (s *DB) Commit() *DB {
 func (s *DB) Rollback() *DB {
 	var emptySQLTx *sql.Tx
 	if db, ok := s.db.(sqlTx); ok && db != nil && db != emptySQLTx {
-		s.AddError(db.Rollback())
+		if err := db.Rollback(); err != nil && err != sql.ErrTxDone {
+			s.AddError(err)
+		}
+	} else {
+		s.AddError(ErrInvalidTransaction)
+	}
+	return s
+}
+
+// RollbackUnlessCommitted rollback a transaction if it has not yet been
+// committed.
+func (s *DB) RollbackUnlessCommitted() *DB {
+	var emptySQLTx *sql.Tx
+	if db, ok := s.db.(sqlTx); ok && db != nil && db != emptySQLTx {
+		err := db.Rollback()
+		// Ignore the error indicating that the transaction has already
+		// been committed.
+		if err != sql.ErrTxDone {
+			s.AddError(err)
+		}
 	} else {
 		s.AddError(ErrInvalidTransaction)
 	}
@ -735,8 +777,8 @@ func (s *DB) SetJoinTableHandler(source interface{}, column string, handler Join
 func (s *DB) AddError(err error) error {
 	if err != nil {
 		if err != ErrRecordNotFound {
-			if s.logMode == 0 {
-				go s.print(fileWithLineNum(), err)
+			if s.logMode == defaultLogMode {
+				go s.print("error", fileWithLineNum(), err)
 			} else {
 				s.log(err)
 			}
@ -800,13 +842,13 @@ func (s *DB) print(v ...interface{}) {
 }

 func (s *DB) log(v ...interface{}) {
-	if s != nil && s.logMode == 2 {
+	if s != nil && s.logMode == detailedLogMode {
 		s.print(append([]interface{}{"log", fileWithLineNum()}, v...)...)
 	}
 }

 func (s *DB) slog(sql string, t time.Time, vars ...interface{}) {
-	if s.logMode == 2 {
+	if s.logMode == detailedLogMode {
 		s.print("sql", fileWithLineNum(), NowFunc().Sub(t), sql, vars, s.RowsAffected)
 	}
 }
--- a/main_test.go
+++ b/main_test.go
@ -1,6 +1,7 @@
 package gorm_test

 import (
+	"context"
 	"database/sql"
 	"database/sql/driver"
 	"fmt"
@ -9,6 +10,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"

@ -277,6 +279,30 @@ func TestTableName(t *testing.T) {
 	DB.SingularTable(false)
 }

+func TestTableNameConcurrently(t *testing.T) {
+	DB := DB.Model("")
+	if DB.NewScope(Order{}).TableName() != "orders" {
+		t.Errorf("Order's table name should be orders")
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(10)
+
+	for i := 1; i <= 10; i++ {
+		go func(db *gorm.DB) {
+			DB.SingularTable(true)
+			wg.Done()
+		}(DB)
+	}
+	wg.Wait()
+
+	if DB.NewScope(Order{}).TableName() != "order" {
+		t.Errorf("Order's singular table name should be order")
+	}
+
+	DB.SingularTable(false)
+}
+
 func TestNullValues(t *testing.T) {
 	DB.DropTable(&NullValue{})
 	DB.AutoMigrate(&NullValue{})
@ -394,6 +420,90 @@ func TestTransaction(t *testing.T) {
 	if err := DB.First(&User{}, "name = ?", "transcation-2").Error; err != nil {
 		t.Errorf("Should be able to find committed record")
 	}
+
+	tx3 := DB.Begin()
+	u3 := User{Name: "transcation-3"}
+	if err := tx3.Save(&u3).Error; err != nil {
+		t.Errorf("No error should raise")
+	}
+
+	if err := tx3.First(&User{}, "name = ?", "transcation-3").Error; err != nil {
+		t.Errorf("Should find saved record")
+	}
+
+	tx3.RollbackUnlessCommitted()
+
+	if err := tx.First(&User{}, "name = ?", "transcation").Error; err == nil {
+		t.Errorf("Should not find record after rollback")
+	}
+
+	tx4 := DB.Begin()
+	u4 := User{Name: "transcation-4"}
+	if err := tx4.Save(&u4).Error; err != nil {
+		t.Errorf("No error should raise")
+	}
+
+	if err := tx4.First(&User{}, "name = ?", "transcation-4").Error; err != nil {
+		t.Errorf("Should find saved record")
+	}
+
+	tx4.Commit()
+
+	tx4.RollbackUnlessCommitted()
+
+	if err := DB.First(&User{}, "name = ?", "transcation-4").Error; err != nil {
+		t.Errorf("Should be able to find committed record")
+	}
+}
+
+func TestTransaction_NoErrorOnRollbackAfterCommit(t *testing.T) {
+	tx := DB.Begin()
+	u := User{Name: "transcation"}
+	if err := tx.Save(&u).Error; err != nil {
+		t.Errorf("No error should raise")
+	}
+
+	if err := tx.Commit().Error; err != nil {
+		t.Errorf("Commit should not raise error")
+	}
+
+	if err := tx.Rollback().Error; err != nil {
+		t.Errorf("Rollback should not raise error")
+	}
+}
+
+func TestTransactionReadonly(t *testing.T) {
+	dialect := os.Getenv("GORM_DIALECT")
+	if dialect == "" {
+		dialect = "sqlite"
+	}
+	switch dialect {
+	case "mssql", "sqlite":
+		t.Skipf("%s does not support readonly transactions\n", dialect)
+	}
+
+	tx := DB.Begin()
+	u := User{Name: "transcation"}
+	if err := tx.Save(&u).Error; err != nil {
+		t.Errorf("No error should raise")
+	}
+	tx.Commit()
+
+	tx = DB.BeginTx(context.Background(), &sql.TxOptions{ReadOnly: true})
+	if err := tx.First(&User{}, "name = ?", "transcation").Error; err != nil {
+		t.Errorf("Should find saved record")
+	}
+
+	if sqlTx, ok := tx.CommonDB().(*sql.Tx); !ok || sqlTx == nil {
+		t.Errorf("Should return the underlying sql.Tx")
+	}
+
+	u = User{Name: "transcation-2"}
+	if err := tx.Save(&u).Error; err == nil {
+		t.Errorf("Error should have been raised in a readonly transaction")
+	}
+
+	tx.Rollback()
 }

 func TestRow(t *testing.T) {
@ -1059,6 +1169,125 @@ func TestBlockGlobalUpdate(t *testing.T) {
 	}
 }

+func TestCountWithHaving(t *testing.T) {
+	db := DB.New()
+	db.Delete(User{})
+	defer db.Delete(User{})
+
+	DB.Create(getPreparedUser("user1", "pluck_user"))
+	DB.Create(getPreparedUser("user2", "pluck_user"))
+	user3 := getPreparedUser("user3", "pluck_user")
+	user3.Languages = []Language{}
+	DB.Create(user3)
+
+	var count int
+	err := db.Model(User{}).Select("users.id").
+		Joins("LEFT JOIN user_languages ON user_languages.user_id = users.id").
+		Joins("LEFT JOIN languages ON user_languages.language_id = languages.id").
+		Group("users.id").Having("COUNT(languages.id) > 1").Count(&count).Error
+
+	if err != nil {
+		t.Error("Unexpected error on query count with having")
+	}
+
+	if count != 2 {
+		t.Error("Unexpected result on query count with having")
+	}
+}
+
+func TestPluck(t *testing.T) {
+	db := DB.New()
+	db.Delete(User{})
+	defer db.Delete(User{})
+
+	DB.Create(&User{Id: 1, Name: "user1"})
+	DB.Create(&User{Id: 2, Name: "user2"})
+	DB.Create(&User{Id: 3, Name: "user3"})
+
+	var ids []int64
+	err := db.Model(User{}).Order("id").Pluck("id", &ids).Error
+
+	if err != nil {
+		t.Error("Unexpected error on pluck")
+	}
+
+	if len(ids) != 3 || ids[0] != 1 || ids[1] != 2 || ids[2] != 3 {
+		t.Error("Unexpected result on pluck")
+	}
+
+	err = db.Model(User{}).Order("id").Pluck("id", &ids).Error
+
+	if err != nil {
+		t.Error("Unexpected error on pluck again")
+	}
+
+	if len(ids) != 3 || ids[0] != 1 || ids[1] != 2 || ids[2] != 3 {
+		t.Error("Unexpected result on pluck again")
+	}
+}
+
+func TestCountWithQueryOption(t *testing.T) {
+	db := DB.New()
+	db.Delete(User{})
+	defer db.Delete(User{})
+
+	DB.Create(&User{Name: "user1"})
+	DB.Create(&User{Name: "user2"})
+	DB.Create(&User{Name: "user3"})
+
+	var count int
+	err := db.Model(User{}).Select("users.id").
+		Set("gorm:query_option", "WHERE users.name='user2'").
+		Count(&count).Error
+
+	if err != nil {
+		t.Error("Unexpected error on query count with query_option")
+	}
+
+	if count != 1 {
+		t.Error("Unexpected result on query count with query_option")
+	}
+}
+
+func TestFloatColumnPrecision(t *testing.T) {
+	if dialect := os.Getenv("GORM_DIALECT"); dialect != "mysql" && dialect != "sqlite" {
+		t.Skip()
+	}
+
+	type FloatTest struct {
+		ID         string  `gorm:"primary_key"`
+		FloatValue float64 `gorm:"column:float_value" sql:"type:float(255,5);"`
+	}
+	DB.DropTable(&FloatTest{})
+	DB.AutoMigrate(&FloatTest{})
+
+	data := FloatTest{ID: "uuid", FloatValue: 112.57315}
+	if err := DB.Save(&data).Error; err != nil || data.ID != "uuid" || data.FloatValue != 112.57315 {
+		t.Errorf("Float value should not lose precision")
+	}
+}
+
+func TestWhereUpdates(t *testing.T) {
+	type OwnerEntity struct {
+		gorm.Model
+		OwnerID   uint
+		OwnerType string
+	}
+
+	type SomeEntity struct {
+		gorm.Model
+		Name        string
+		OwnerEntity OwnerEntity `gorm:"polymorphic:Owner"`
+	}
+
+	db := DB.Debug()
+	db.DropTable(&SomeEntity{})
+	db.AutoMigrate(&SomeEntity{})
+
+	a := SomeEntity{Name: "test"}
+	db.Model(&a).Where(a).Updates(SomeEntity{Name: "test2"})
+}
+
 func BenchmarkGorm(b *testing.B) {
 	b.N = 2000
 	for x := 0; x < b.N; x++ {
--- a/migration_test.go
+++ b/migration_test.go
@ -538,3 +538,42 @@ func TestModifyColumnType(t *testing.T) {
 		t.Errorf("No error should happen when ModifyColumn, but got %v", err)
 	}
 }
+
+func TestIndexWithPrefixLength(t *testing.T) {
+	if dialect := os.Getenv("GORM_DIALECT"); dialect != "mysql" {
+		t.Skip("Skipping this because only mysql support setting an index prefix length")
+	}
+
+	type IndexWithPrefix struct {
+		gorm.Model
+		Name        string
+		Description string `gorm:"type:text;index:idx_index_with_prefixes_length(100)"`
+	}
+	type IndexesWithPrefix struct {
+		gorm.Model
+		Name         string
+		Description1 string `gorm:"type:text;index:idx_index_with_prefixes_length(100)"`
+		Description2 string `gorm:"type:text;index:idx_index_with_prefixes_length(100)"`
+	}
+	type IndexesWithPrefixAndWithoutPrefix struct {
+		gorm.Model
+		Name        string `gorm:"index:idx_index_with_prefixes_length"`
+		Description string `gorm:"type:text;index:idx_index_with_prefixes_length(100)"`
+	}
+	tables := []interface{}{&IndexWithPrefix{}, &IndexesWithPrefix{}, &IndexesWithPrefixAndWithoutPrefix{}}
+	for _, table := range tables {
+		scope := DB.NewScope(table)
+		tableName := scope.TableName()
+		t.Run(fmt.Sprintf("Create index with prefix length: %s", tableName), func(t *testing.T) {
+			if err := DB.DropTableIfExists(table).Error; err != nil {
+				t.Errorf("Failed to drop %s table: %v", tableName, err)
+			}
+			if err := DB.CreateTable(table).Error; err != nil {
+				t.Errorf("Failed to create %s table: %v", tableName, err)
+			}
+			if !scope.Dialect().HasIndex(tableName, "idx_index_with_prefixes_length") {
+				t.Errorf("Failed to create %s table index:", tableName)
+			}
+		})
+	}
+}
--- a/model_struct.go
+++ b/model_struct.go
@ -21,12 +21,12 @@ var modelStructsMap sync.Map

 // ModelStruct model definition
 type ModelStruct struct {
-	PrimaryFields    []*StructField
-	StructFields     []*StructField
-	ModelType        reflect.Type
+	PrimaryFields []*StructField
+	StructFields  []*StructField
+	ModelType     reflect.Type

 	defaultTableName string
-	l sync.Mutex
+	l                sync.Mutex
 }

 // TableName returns model's table name
@ -40,9 +40,11 @@ func (s *ModelStruct) TableName(db *DB) string {
 			s.defaultTableName = tabler.TableName()
 		} else {
 			tableName := ToTableName(s.ModelType.Name())
-			if db == nil || !db.parent.singularTable {
+			db.parent.RLock()
+			if db == nil || (db.parent != nil && !db.parent.singularTable) {
 				tableName = inflection.Plural(tableName)
 			}
+			db.parent.RUnlock()
 			s.defaultTableName = tableName
 		}
 	}
@ -70,52 +72,52 @@ type StructField struct {
 }

 // TagSettingsSet Sets a tag in the tag settings map
-func (s *StructField) TagSettingsSet(key, val string) {
-	s.tagSettingsLock.Lock()
-	defer s.tagSettingsLock.Unlock()
-	s.TagSettings[key] = val
+func (sf *StructField) TagSettingsSet(key, val string) {
+	sf.tagSettingsLock.Lock()
+	defer sf.tagSettingsLock.Unlock()
+	sf.TagSettings[key] = val
 }

 // TagSettingsGet returns a tag from the tag settings
-func (s *StructField) TagSettingsGet(key string) (string, bool) {
-	s.tagSettingsLock.RLock()
-	defer s.tagSettingsLock.RUnlock()
-	val, ok := s.TagSettings[key]
+func (sf *StructField) TagSettingsGet(key string) (string, bool) {
+	sf.tagSettingsLock.RLock()
+	defer sf.tagSettingsLock.RUnlock()
+	val, ok := sf.TagSettings[key]
 	return val, ok
 }

 // TagSettingsDelete deletes a tag
-func (s *StructField) TagSettingsDelete(key string) {
-	s.tagSettingsLock.Lock()
-	defer s.tagSettingsLock.Unlock()
-	delete(s.TagSettings, key)
+func (sf *StructField) TagSettingsDelete(key string) {
+	sf.tagSettingsLock.Lock()
+	defer sf.tagSettingsLock.Unlock()
+	delete(sf.TagSettings, key)
 }

-func (structField *StructField) clone() *StructField {
+func (sf *StructField) clone() *StructField {
 	clone := &StructField{
-		DBName:          structField.DBName,
-		Name:            structField.Name,
-		Names:           structField.Names,
-		IsPrimaryKey:    structField.IsPrimaryKey,
-		IsNormal:        structField.IsNormal,
-		IsIgnored:       structField.IsIgnored,
-		IsScanner:       structField.IsScanner,
-		HasDefaultValue: structField.HasDefaultValue,
-		Tag:             structField.Tag,
+		DBName:          sf.DBName,
+		Name:            sf.Name,
+		Names:           sf.Names,
+		IsPrimaryKey:    sf.IsPrimaryKey,
+		IsNormal:        sf.IsNormal,
+		IsIgnored:       sf.IsIgnored,
+		IsScanner:       sf.IsScanner,
+		HasDefaultValue: sf.HasDefaultValue,
+		Tag:             sf.Tag,
 		TagSettings:     map[string]string{},
-		Struct:          structField.Struct,
-		IsForeignKey:    structField.IsForeignKey,
+		Struct:          sf.Struct,
+		IsForeignKey:    sf.IsForeignKey,
 	}

-	if structField.Relationship != nil {
-		relationship := *structField.Relationship
+	if sf.Relationship != nil {
+		relationship := *sf.Relationship
 		clone.Relationship = &relationship
 	}

 	// copy the struct field tagSettings, they should be read-locked while they are copied
-	structField.tagSettingsLock.Lock()
-	defer structField.tagSettingsLock.Unlock()
-	for key, value := range structField.TagSettings {
+	sf.tagSettingsLock.Lock()
+	defer sf.tagSettingsLock.Unlock()
+	for key, value := range sf.TagSettings {
 		clone.TagSettings[key] = value
 	}

@ -163,7 +165,18 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 	}

 	// Get Cached model struct
-	if value, ok := modelStructsMap.Load(reflectType); ok && value != nil {
+	isSingularTable := false
+	if scope.db != nil && scope.db.parent != nil {
+		scope.db.parent.RLock()
+		isSingularTable = scope.db.parent.singularTable
+		scope.db.parent.RUnlock()
+	}
+
+	hashKey := struct {
+		singularTable bool
+		reflectType   reflect.Type
+	}{isSingularTable, reflectType}
+	if value, ok := modelStructsMap.Load(hashKey); ok && value != nil {
 		return value.(*ModelStruct)
 	}

@ -189,7 +202,7 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 					modelStruct.PrimaryFields = append(modelStruct.PrimaryFields, field)
 				}

-				if _, ok := field.TagSettingsGet("DEFAULT"); ok {
+				if _, ok := field.TagSettingsGet("DEFAULT"); ok && !field.IsPrimaryKey {
 					field.HasDefaultValue = true
 				}

@ -340,7 +353,7 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 									}

 									joinTableHandler := JoinTableHandler{}
-									joinTableHandler.Setup(relationship, ToTableName(many2many), reflectType, elemType)
+									joinTableHandler.Setup(relationship, many2many, reflectType, elemType)
 									relationship.JoinTableHandler = &joinTableHandler
 									field.Relationship = relationship
 								} else {
@ -612,7 +625,7 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 		}
 	}

-	modelStructsMap.Store(reflectType, &modelStruct)
+	modelStructsMap.Store(hashKey, &modelStruct)

 	return &modelStruct
 }
@ -625,6 +638,9 @@ func (scope *Scope) GetStructFields() (fields []*StructField) {
 func parseTagSetting(tags reflect.StructTag) map[string]string {
 	setting := map[string]string{}
 	for _, str := range []string{tags.Get("sql"), tags.Get("gorm")} {
+		if str == "" {
+			continue
+		}
 		tags := strings.Split(str, ";")
 		for _, value := range tags {
 			v := strings.Split(value, ":")
--- a/preload_test.go
+++ b/preload_test.go
@ -771,6 +771,7 @@ func TestNestedPreload11(t *testing.T) {
 	levelB3 := &LevelB3{
 		Value:     "bar",
 		LevelB1ID: sql.NullInt64{Valid: true, Int64: int64(levelB1.ID)},
+		LevelB2s:  []*LevelB2{},
 	}
 	if err := DB.Create(levelB3).Error; err != nil {
 		t.Error(err)
@ -1676,7 +1677,7 @@ func TestPreloadManyToManyCallbacks(t *testing.T) {
 	lvl := Level1{
 		Name: "l1",
 		Level2s: []Level2{
-			Level2{Name: "l2-1"}, Level2{Name: "l2-2"},
+			{Name: "l2-1"}, {Name: "l2-2"},
 		},
 	}
 	DB.Save(&lvl)
--- a/scope.go
+++ b/scope.go
@ -68,7 +68,7 @@ func (scope *Scope) Dialect() Dialect {

 // Quote used to quote string to escape them for database
 func (scope *Scope) Quote(str string) string {
-	if strings.Index(str, ".") != -1 {
+	if strings.Contains(str, ".") {
 		newStrs := []string{}
 		for _, str := range strings.Split(str, ".") {
 			newStrs = append(newStrs, scope.Dialect().Quote(str))
@ -330,7 +330,7 @@ func (scope *Scope) TableName() string {
 // QuotedTableName return quoted table name
 func (scope *Scope) QuotedTableName() (name string) {
 	if scope.Search != nil && len(scope.Search.tableName) > 0 {
-		if strings.Index(scope.Search.tableName, " ") != -1 {
+		if strings.Contains(scope.Search.tableName, " ") {
 			return scope.Search.tableName
 		}
 		return scope.Quote(scope.Search.tableName)
@ -402,7 +402,7 @@ func (scope *Scope) InstanceGet(name string) (interface{}, bool) {
 // Begin start a transaction
 func (scope *Scope) Begin() *Scope {
 	if db, ok := scope.SQLDB().(sqlDb); ok {
-		if tx, err := db.Begin(); err == nil {
+		if tx, err := db.Begin(); scope.Err(err) == nil {
 			scope.db.db = interface{}(tx).(SQLCommon)
 			scope.InstanceSet("gorm:started_transaction", true)
 		}
@ -872,7 +872,7 @@ func (scope *Scope) callCallbacks(funcs []*func(s *Scope)) *Scope {
 	return scope
 }

-func convertInterfaceToMap(values interface{}, withIgnoredField bool) map[string]interface{} {
+func convertInterfaceToMap(values interface{}, withIgnoredField bool, db *DB) map[string]interface{} {
 	var attrs = map[string]interface{}{}

 	switch value := values.(type) {
@ -880,7 +880,7 @@ func convertInterfaceToMap(values interface{}, withIgnoredField bool) map[string
 		return value
 	case []interface{}:
 		for _, v := range value {
-			for key, value := range convertInterfaceToMap(v, withIgnoredField) {
+			for key, value := range convertInterfaceToMap(v, withIgnoredField, db) {
 				attrs[key] = value
 			}
 		}
@ -893,7 +893,7 @@ func convertInterfaceToMap(values interface{}, withIgnoredField bool) map[string
 				attrs[ToColumnName(key.Interface().(string))] = reflectValue.MapIndex(key).Interface()
 			}
 		default:
-			for _, field := range (&Scope{Value: values}).Fields() {
+			for _, field := range (&Scope{Value: values, db: db}).Fields() {
 				if !field.IsBlank && (withIgnoredField || !field.IsIgnored) {
 					attrs[field.DBName] = field.Field.Interface()
 				}
@ -905,12 +905,12 @@ func convertInterfaceToMap(values interface{}, withIgnoredField bool) map[string

 func (scope *Scope) updatedAttrsWithValues(value interface{}) (results map[string]interface{}, hasUpdate bool) {
 	if scope.IndirectValue().Kind() != reflect.Struct {
-		return convertInterfaceToMap(value, false), true
+		return convertInterfaceToMap(value, false, scope.db), true
 	}

 	results = map[string]interface{}{}

-	for key, value := range convertInterfaceToMap(value, true) {
+	for key, value := range convertInterfaceToMap(value, true, scope.db) {
 		if field, ok := scope.FieldByName(key); ok && scope.changeableField(field) {
 			if _, ok := value.(*expr); ok {
 				hasUpdate = true
@ -984,6 +984,10 @@ func (scope *Scope) pluck(column string, value interface{}) *Scope {
 		return scope
 	}

+	if dest.Len() > 0 {
+		dest.Set(reflect.Zero(dest.Type()))
+	}
+
 	if query, ok := scope.Search.selects["query"]; !ok || !scope.isQueryForColumn(query, column) {
 		scope.Search.Select(column)
 	}
@ -1007,8 +1011,15 @@ func (scope *Scope) pluck(column string, value interface{}) *Scope {
 func (scope *Scope) count(value interface{}) *Scope {
 	if query, ok := scope.Search.selects["query"]; !ok || !countingQueryRegexp.MatchString(fmt.Sprint(query)) {
 		if len(scope.Search.group) != 0 {
-			scope.Search.Select("count(*) FROM ( SELECT count(*) as name ")
-			scope.Search.group += " ) AS count_table"
+			if len(scope.Search.havingConditions) != 0 {
+				scope.prepareQuerySQL()
+				scope.Search = &search{}
+				scope.Search.Select("count(*)")
+				scope.Search.Table(fmt.Sprintf("( %s ) AS count_table", scope.SQL))
+			} else {
+				scope.Search.Select("count(*) FROM ( SELECT count(*) as name ")
+				scope.Search.group += " ) AS count_table"
+			}
 		} else {
 			scope.Search.Select("count(*)")
 		}
@ -1183,7 +1194,7 @@ func (scope *Scope) createTable() *Scope {
 }

 func (scope *Scope) dropTable() *Scope {
-	scope.Raw(fmt.Sprintf("DROP TABLE %v%s", scope.QuotedTableName(), scope.getTableOptions())).Exec()
+	scope.Raw(fmt.Sprintf("DROP TABLE %v", scope.QuotedTableName())).Exec()
 	return scope
 }

@ -1277,7 +1288,8 @@ func (scope *Scope) autoIndex() *Scope {
 				if name == "INDEX" || name == "" {
 					name = scope.Dialect().BuildKeyName("idx", scope.TableName(), field.DBName)
 				}
-				indexes[name] = append(indexes[name], field.DBName)
+				name, column := scope.Dialect().NormalizeIndexAndColumn(name, field.DBName)
+				indexes[name] = append(indexes[name], column)
 			}
 		}

@ -1288,7 +1300,8 @@ func (scope *Scope) autoIndex() *Scope {
 				if name == "UNIQUE_INDEX" || name == "" {
 					name = scope.Dialect().BuildKeyName("uix", scope.TableName(), field.DBName)
 				}
-				uniqueIndexes[name] = append(uniqueIndexes[name], field.DBName)
+				name, column := scope.Dialect().NormalizeIndexAndColumn(name, field.DBName)
+				uniqueIndexes[name] = append(uniqueIndexes[name], column)
 			}
 		}
 	}
@ -1309,6 +1322,7 @@ func (scope *Scope) autoIndex() *Scope {
 }

 func (scope *Scope) getColumnAsArray(columns []string, values ...interface{}) (results [][]interface{}) {
+	resultMap := make(map[string][]interface{})
 	for _, value := range values {
 		indirectValue := indirect(reflect.ValueOf(value))

@ -1327,7 +1341,10 @@ func (scope *Scope) getColumnAsArray(columns []string, values ...interface{}) (r
 				}

 				if hasValue {
-					results = append(results, result)
+					h := fmt.Sprint(result...)
+					if _, exist := resultMap[h]; !exist {
+						resultMap[h] = result
+					}
 				}
 			}
 		case reflect.Struct:
@ -1342,11 +1359,16 @@ func (scope *Scope) getColumnAsArray(columns []string, values ...interface{}) (r
 			}

 			if hasValue {
-				results = append(results, result)
+				h := fmt.Sprint(result...)
+				if _, exist := resultMap[h]; !exist {
+					resultMap[h] = result
+				}
 			}
 		}
 	}
-
+	for _, v := range resultMap {
+		results = append(results, v)
+	}
 	return
 }

--- a/scope_test.go
+++ b/scope_test.go
@ -78,3 +78,16 @@ func TestFailedValuer(t *testing.T) {
 		t.Errorf("The error should be returned from Valuer, but get %v", err)
 	}
 }
+
+func TestDropTableWithTableOptions(t *testing.T) {
+	type UserWithOptions struct {
+		gorm.Model
+	}
+	DB.AutoMigrate(&UserWithOptions{})
+
+	DB = DB.Set("gorm:table_options", "CHARSET=utf8")
+	err := DB.DropTable(&UserWithOptions{}).Error
+	if err != nil {
+		t.Errorf("Table must be dropped, got error %s", err)
+	}
+}
--- a/wercker.yml
+++ b/wercker.yml
@ -83,7 +83,7 @@ build:
                code: |
                    cd $WERCKER_SOURCE_DIR
                    go version
-                    go get -t ./...
+                    go get -t -v ./...

        # Build the project
        - script:
@ -95,54 +95,60 @@ build:
        - script:
                name: test sqlite
                code: |
-                    go test ./...
+                    go test -race -v ./...

        - script:
                name: test mariadb
                code: |
-                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mariadb:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mariadb:3306)/gorm?charset=utf8&parseTime=True" go test -race ./...

        - script:
                name: test mysql5.7
                code: |
-                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql57:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql57:3306)/gorm?charset=utf8&parseTime=True" go test -race ./...

        - script:
                name: test mysql5.6
                code: |
-                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql56:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql56:3306)/gorm?charset=utf8&parseTime=True" go test -race ./...

        - script:
                name: test mysql5.5
                code: |
-                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql55:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql55:3306)/gorm?charset=utf8&parseTime=True" go test -race ./...

        - script:
                name: test postgres
                code: |
-                    GORM_DIALECT=postgres GORM_DSN="host=postgres user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test -race ./...

        - script:
                name: test postgres96
                code: |
-                    GORM_DIALECT=postgres GORM_DSN="host=postgres96 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres96 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test -race ./...

        - script:
                name: test postgres95
                code: |
-                    GORM_DIALECT=postgres GORM_DSN="host=postgres95 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres95 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test -race ./...

        - script:
                name: test postgres94
                code: |
-                    GORM_DIALECT=postgres GORM_DSN="host=postgres94 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres94 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test -race ./...

        - script:
                name: test postgres93
                code: |
-                    GORM_DIALECT=postgres GORM_DSN="host=postgres93 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres93 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test -race ./...

        - script:
                name: test mssql
                code: |
-                    GORM_DIALECT=mssql GORM_DSN="sqlserver://gorm:LoremIpsum86@mssql:1433?database=gorm" go test ./...
+                    GORM_DIALECT=mssql GORM_DSN="sqlserver://gorm:LoremIpsum86@mssql:1433?database=gorm" go test -race ./...
+
+        - script:
+                name: codecov
+                code: |
+                    go test -race -coverprofile=coverage.txt -covermode=atomic ./...
+                    bash <(curl -s https://codecov.io/bash)