Added redshift support & added Dialect.SupportLastInsertID interface method

.gitignore

@@ -1,2 +1,3 @@
 documents
 _book
+.DS_Store

callback_create.go

@@ -109,8 +109,32 @@ func createCallback(scope *Scope) {
 				// set rows affected count
 				scope.db.RowsAffected, _ = result.RowsAffected()
 
-				// set primary value to primary field
-				if primaryField != nil && primaryField.IsBlank {
+				// Set primary value to primary field
+				// * If `LastInsertID` isn't supported, then pull the last inserted row from the db
+				// * Else, use the `LastInsertID` field stored in `result`
+				if !scope.Dialect().SupportLastInsertID() && primaryField != nil {
+					// Build the WHERE query for each inserted column
+					where_filter := make([]string, len(columns))
+					for i, column := range columns {
+						where_filter[i] = fmt.Sprintf("%v = $%v", column, i + 1)
+					}
+					// Store the query in scope.SQL
+					scope.Raw(fmt.Sprintf(
+						"SELECT \"%v\" FROM %v WHERE %v ORDER BY \"%v\" DESC LIMIT 1",
+						primaryField.Name,
+						scope.QuotedTableName(),
+						strings.Join(where_filter, " AND "),
+						primaryField.Name,
+					))
+					// Execute the query and store the results in primaryField & scope.Err
+					var id int64
+					if err := scope.SQLDB().QueryRow(scope.SQL, scope.SQLVars...).Scan(&id); err == nil {
+						primaryField.Set(id)
+						scope.Err(nil)
+					} else {
+						scope.Err(primaryField.Set(err.Error()))
+					}
+				} else if primaryField != nil && primaryField.IsBlank {
 					if primaryValue, err := result.LastInsertId(); scope.Err(err) == nil {
 						scope.Err(primaryField.Set(primaryValue))
 					}

dialect.go

@@ -40,6 +40,7 @@ type Dialect interface {
 	SelectFromDummyTable() string
 	// LastInsertIdReturningSuffix most dbs support LastInsertId, but postgres needs to use `RETURNING`
 	LastInsertIDReturningSuffix(tableName, columnName string) string
+	SupportLastInsertID() bool
 
 	// BuildForeignKeyName returns a foreign key name for the given table, field and reference
 	BuildForeignKeyName(tableName, field, dest string) string

dialect_common.go

@@ -145,6 +145,10 @@ func (commonDialect) LastInsertIDReturningSuffix(tableName, columnName string) s
 	return ""
 }
 
+func (commonDialect) SupportLastInsertID() bool {
+	return true
+}
+
 func (DefaultForeignKeyNamer) BuildForeignKeyName(tableName, field, dest string) string {
 	keyName := fmt.Sprintf("%s_%s_%s_foreign", tableName, field, dest)
 	keyName = regexp.MustCompile("(_*[^a-zA-Z]+_*|_+)").ReplaceAllString(keyName, "_")

dialect_mysql.go

@@ -144,3 +144,7 @@ func (s mysql) BuildForeignKeyName(tableName, field, dest string) string {
 
 	return fmt.Sprintf("%s%x", string(destRunes), bs)
 }
+
+func (mysql) SupportLastInsertID() bool {
+	return true
+}

dialect_redshift.go

@@ -0,0 +1,123 @@
+package gorm
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"time"
+)
+
+type redshift struct {
+	commonDialect
+}
+
+func init() {
+	RegisterDialect("redshift", &redshift{})
+}
+
+func (redshift) GetName() string {
+	return "redshift"
+}
+
+func (redshift) BindVar(i int) string {
+	return fmt.Sprintf("$%v", i)
+}
+
+func (redshift) DataTypeOf(field *StructField) string {
+	var dataValue, sqlType, size, additionalType = ParseFieldStructForDialect(field)
+
+	if sqlType == "" {
+		switch dataValue.Kind() {
+		case reflect.Bool:
+			sqlType = "boolean"
+		case reflect.Float32:
+			sqlType = "float4"
+		case reflect.Float64:
+			sqlType = "float8"
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32:
+			if field.IsPrimaryKey {
+				delete(field.TagSettings, "AUTO_INCREMENT")
+				delete(field.TagSettings, "IDENTITY(1, 1)")
+				sqlType = "integer IDENTITY(1, 1)"
+			} else if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok {
+				delete(field.TagSettings, "AUTO_INCREMENT")
+				delete(field.TagSettings, "IDENTITY(1, 1)")
+				sqlType = "integer IDENTITY(1, 1)"
+			} else if _, ok := field.TagSettings["IDENTITY(1, 1)"]; ok {
+				delete(field.TagSettings, "AUTO_INCREMENT")
+				delete(field.TagSettings, "IDENTITY(1, 1)")
+				sqlType = "integer IDENTITY(1, 1)"
+			} else {
+				sqlType = "integer"
+			}
+		case reflect.Int64, reflect.Uintptr, reflect.Uint64:
+			if _, ok := field.TagSettings["IDENTITY(1, 1)"]; ok || field.IsPrimaryKey {
+				field.TagSettings["IDENTITY(1, 1)"] = "IDENTITY(1, 1)"
+				sqlType = "bigint"
+			} else {
+				sqlType = "bigint"
+			}
+		case reflect.String:
+			if _, ok := field.TagSettings["SIZE"]; !ok {
+				size = 0 // if SIZE haven't been set, use `text` as the default type, as there are no performance different
+			}
+			if size > 0 && size < 65532 {
+				sqlType = fmt.Sprintf("varchar(%d)", size)
+			} else {
+				sqlType = "text"
+			}
+		case reflect.Struct:
+			if _, ok := dataValue.Interface().(time.Time); ok {
+				sqlType = "timestamp with time zone"
+			}
+		default:
+			sqlType = ""
+		}
+	}
+
+	if sqlType == "" {
+		panic(fmt.Sprintf("invalid sql type %s (%s) for redshift", dataValue.Type().Name(), dataValue.Kind().String()))
+	}
+
+	if strings.TrimSpace(additionalType) == "" {
+		return sqlType
+	}
+	return fmt.Sprintf("%v %v", sqlType, additionalType)
+}
+
+func (s redshift) HasIndex(tableName string, indexName string) bool {
+	var count int
+	s.db.QueryRow("SELECT count(*) FROM pg_indexes WHERE tablename = $1 AND indexname = $2", tableName, indexName).Scan(&count)
+	return count > 0
+}
+
+func (s redshift) HasForeignKey(tableName string, foreignKeyName string) bool {
+	var count int
+	s.db.QueryRow("SELECT count(con.conname) FROM pg_constraint con WHERE $1::regclass::oid = con.conrelid AND con.conname = $2 AND con.contype='f'", tableName, foreignKeyName).Scan(&count)
+	return count > 0
+}
+
+func (s redshift) HasTable(tableName string) bool {
+	var count int
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = $1 AND table_type = 'BASE TABLE'", tableName).Scan(&count)
+	return count > 0
+}
+
+func (s redshift) HasColumn(tableName string, columnName string) bool {
+	var count int
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_name = $1 AND column_name = $2", tableName, columnName).Scan(&count)
+	return count > 0
+}
+
+func (s redshift) CurrentDatabase() (name string) {
+	s.db.QueryRow("SELECT CURRENT_DATABASE()").Scan(&name)
+	return
+}
+
+func (s redshift) LastInsertIDReturningSuffix(tableName, key string) string {
+	return ""
+}
+
+func (redshift) SupportLastInsertID() bool {
+	return false
+}

dialect_sqlite3.go

@@ -106,3 +106,7 @@ func (s sqlite3) CurrentDatabase() (name string) {
 	}
 	return
 }
+
+func (sqlite3) SupportLastInsertID() bool {
+	return true
+}

dialects/mssql/mssql.go

@@ -149,3 +149,7 @@ func (mssql) SelectFromDummyTable() string {
 func (mssql) LastInsertIDReturningSuffix(tableName, columnName string) string {
 	return ""
 }
+
+func (mssql) SupportLastInsertID() bool {
+	return true
+}

dialects/redshift/redshift.go

@@ -0,0 +1,7 @@
+package redshift
+
+import (
+	_ "database/sql"
+	_ "database/sql/driver"
+	_ "github.com/lib/pq"
+)