modify unique to constraint

migrator/migrator.go

@@ -26,6 +26,8 @@ type Migrator struct {
 // Config schema config
 type Config struct {
 	CreateIndexAfterCreateTable bool
+	// Unique in ColumnType is affected by UniqueIndex, e.g. MySQL
+	UniqueAffectedByUniqueIndex bool
 	DB                          *gorm.DB
 	gorm.Dialector
 }
@@ -117,7 +119,6 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 				var (
 					parseIndexes          = stmt.Schema.ParseIndexes()
 					parseCheckConstraints = stmt.Schema.ParseCheckConstraints()
-					parseUniqueConstraints = stmt.Schema.ParseUniqueConstraints()
 				)
 				for _, dbName := range stmt.Schema.DBNames {
 					var foundColumn gorm.ColumnType
@@ -157,14 +158,6 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 					}
 				}
 
-				for _, uni := range parseUniqueConstraints {
-					if !queryTx.Migrator().HasConstraint(value, uni.Name) {
-						if err := execTx.Migrator().CreateConstraint(value, uni.Name); err != nil {
-							return err
-						}
-					}
-				}
-
 				for _, chk := range parseCheckConstraints {
 					if !queryTx.Migrator().HasConstraint(value, chk.Name) {
 						if err := execTx.Migrator().CreateConstraint(value, chk.Name); err != nil {
@@ -438,6 +431,10 @@ func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error
 
 // MigrateColumn migrate column
 func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnType gorm.ColumnType) error {
+	if field.IgnoreMigration {
+		return nil
+	}
+
 	// found, smart migrate
 	fullDataType := strings.TrimSpace(strings.ToLower(m.DB.Migrator().FullDataTypeOf(field).SQL))
 	realDataType := strings.ToLower(columnType.DatabaseTypeName())
@@ -497,14 +494,6 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 		}
 	}
 
-	// check unique
-	if unique, ok := columnType.Unique(); ok && !unique && (field.Unique || field.UniqueIndex) {
-		// not primary key
-		if !field.PrimaryKey {
-			alterColumn = true
-		}
-	}
-
 	// check default value
 	if !field.PrimaryKey {
 		currentDefaultNotNull := field.HasDefaultValue && (field.DefaultValueInterface != nil || !strings.EqualFold(field.DefaultValue, "NULL"))
@@ -533,13 +522,101 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 		}
 	}
 
-	if alterColumn && !field.IgnoreMigration {
+	if alterColumn {
-		return m.DB.Migrator().AlterColumn(value, field.DBName)
+		if err := m.DB.Migrator().AlterColumn(value, field.DBName); err != nil {
+			return err
+		}
+	}
+
+	if err := m.MigrateColumnUnique(value, field, columnType); err != nil {
+		return err
 	}
 
 	return nil
 }
 
+func (m Migrator) MigrateColumnUnique(value interface{}, field *schema.Field, columnType gorm.ColumnType) error {
+	unique, ok := columnType.Unique()
+	if !ok || field.PrimaryKey {
+		return nil // skip primary key
+	}
+
+	queryTx := m.DB.Session(&gorm.Session{})
+	execTx := queryTx
+	if m.DB.DryRun {
+		queryTx.DryRun = false
+		execTx = m.DB.Session(&gorm.Session{Logger: &printSQLLogger{Interface: m.DB.Logger}})
+	}
+
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		constraint := m.DB.NamingStrategy.UniqueName(stmt.Table, field.DBName)
+		index := m.DB.NamingStrategy.IndexName(stmt.Table, field.DBName)
+
+		if m.UniqueAffectedByUniqueIndex {
+			if unique {
+				hasConstraint := queryTx.Migrator().HasConstraint(value, constraint)
+				switch {
+				case field.Unique && !hasConstraint:
+					if field.Unique {
+						if err := execTx.Migrator().CreateConstraint(value, constraint); err != nil {
+							return err
+						}
+					}
+				// field isn't Unique but ColumnType's Unique is reported by UniqueConstraint.
+				case !field.Unique && hasConstraint:
+					if err := execTx.Migrator().DropConstraint(value, constraint); err != nil {
+						return err
+					}
+					if field.UniqueIndex {
+						if err := execTx.Migrator().CreateIndex(value, index); err != nil {
+							return err
+						}
+					}
+				}
+
+				hasIndex := queryTx.Migrator().HasIndex(value, index)
+				switch {
+				case field.UniqueIndex && !hasIndex:
+					if err := execTx.Migrator().CreateIndex(value, index); err != nil {
+						return err
+					}
+				// field isn't UniqueIndex but ColumnType's Unique is reported by UniqueIndex
+				case !field.UniqueIndex && hasIndex:
+					if err := execTx.Migrator().DropIndex(value, index); err != nil {
+						return err
+					}
+					// create normal index
+					if idx := stmt.Schema.LookIndex(index); idx != nil {
+						if err := execTx.Migrator().CreateIndex(value, index); err != nil {
+							return err
+						}
+					}
+				}
+			} else {
+				if field.Unique {
+					if err := execTx.Migrator().CreateConstraint(value, constraint); err != nil {
+						return err
+					}
+				}
+				if field.UniqueIndex {
+					if err := execTx.Migrator().CreateIndex(value, index); err != nil {
+						return err
+					}
+				}
+				return nil
+			}
+		} else {
+			if unique && !field.Unique {
+				return execTx.Migrator().DropConstraint(value, constraint)
+			}
+			if !unique && field.Unique {
+				return execTx.Migrator().CreateConstraint(value, constraint)
+			}
+		}
+		return nil
+	})
+}
+
 // ColumnTypes return columnTypes []gorm.ColumnType and execErr error
 func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
 	columnTypes := make([]gorm.ColumnType, 0)
@@ -610,7 +687,22 @@ func (m Migrator) DropView(name string) error {
 }
 
 // GuessConstraintAndTable guess statement's constraint and it's table based on name
-func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_ schema.ConstraintInterface, table string) {
+//
+// Deprecated: use GuessConstraintInterfaceAndTable instead.
+func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (*schema.Constraint, *schema.CheckConstraint, string) {
+	constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
+	switch c := constraint.(type) {
+	case *schema.Constraint:
+		return c, nil, table
+	case *schema.CheckConstraint:
+		return nil, c, table
+	default:
+		return nil, nil, table
+	}
+}
+
+// GuessConstraintInterfaceAndTable guess statement's constraint and it's table based on name
+func (m Migrator) GuessConstraintInterfaceAndTable(stmt *gorm.Statement, name string) (_ schema.ConstraintInterface, table string) {
 	if stmt.Schema == nil {
 		return nil, stmt.Table
 	}
@@ -669,7 +761,7 @@ func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_
 // CreateConstraint create constraint
 func (m Migrator) CreateConstraint(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
 			vars := []interface{}{clause.Table{Name: table}}
 			if stmt.TableExpr != nil {
@@ -685,7 +777,7 @@ func (m Migrator) CreateConstraint(value interface{}, name string) error {
 // DropConstraint drop constraint
 func (m Migrator) DropConstraint(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
 			name = constraint.GetName()
 		}
@@ -698,7 +790,7 @@ func (m Migrator) HasConstraint(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
-		constraint, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
 			name = constraint.GetName()
 		}

schema/relationship.go

@@ -566,7 +566,8 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	}
 }
 
-type FKConstraint struct {
+// Constraint is ForeignKey Constraint
+type Constraint struct {
 	Name            string
 	Field           *Field
 	Schema          *Schema
@@ -577,9 +578,9 @@ type FKConstraint struct {
 	OnUpdate        string
 }
 
-func (constraint *FKConstraint) GetName() string { return constraint.Name }
+func (constraint *Constraint) GetName() string { return constraint.Name }
 
-func (constraint *FKConstraint) Build() (sql string, vars []interface{}) {
+func (constraint *Constraint) Build() (sql string, vars []interface{}) {
 	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
 	if constraint.OnDelete != "" {
 		sql += " ON DELETE " + constraint.OnDelete
@@ -601,7 +602,7 @@ func (constraint *FKConstraint) Build() (sql string, vars []interface{}) {
 	return
 }
 
-func (rel *Relationship) ParseConstraint() *FKConstraint {
+func (rel *Relationship) ParseConstraint() *Constraint {
 	str := rel.Field.TagSettings["CONSTRAINT"]
 	if str == "-" {
 		return nil
@@ -641,7 +642,7 @@ func (rel *Relationship) ParseConstraint() *FKConstraint {
 		name = rel.Schema.namer.RelationshipFKName(*rel)
 	}
 
-	constraint := FKConstraint{
+	constraint := Constraint{
 		Name:     name,
 		Field:    rel.Field,
 		OnUpdate: settings["ONUPDATE"],

tests/migrate_test.go

@@ -1654,40 +1654,46 @@ func TestMigrateWithUniqueIndexAndUnique(t *testing.T) {
 	}
 
 	// not unique
-	type UniqueStruct1 struct {
+	type (
+		UniqueStruct1 struct {
+			Name string `gorm:"size:10"`
+		}
+		UniqueStruct2 struct {
 			Name string `gorm:"size:20"`
 		}
+	)
 	checkField(&UniqueStruct1{}, "name", false, false)
+	checkField(&UniqueStruct2{}, "name", false, false)
 
 	type ( // unique
-		UniqueStruct2 struct {
-			Name string `gorm:"size:20;unique"`
-		}
 		UniqueStruct3 struct {
 			Name string `gorm:"size:30;unique"`
 		}
+		UniqueStruct4 struct {
+			Name string `gorm:"size:40;unique"`
+		}
 	)
-	checkField(&UniqueStruct2{}, "name", true, false)
 	checkField(&UniqueStruct3{}, "name", true, false)
+	checkField(&UniqueStruct4{}, "name", true, false)
 
 	type ( // uniqueIndex
-		UniqueStruct4 struct {
-			Name string `gorm:"size:40;uniqueIndex"`
-		}
 		UniqueStruct5 struct {
 			Name string `gorm:"size:50;uniqueIndex"`
 		}
 		UniqueStruct6 struct {
-			Name     string `gorm:"size:20;uniqueIndex:idx_us6_all_names"`
+			Name string `gorm:"size:60;uniqueIndex"`
-			NickName string `gorm:"size:20;uniqueIndex:idx_us6_all_names"`
+		}
+		UniqueStruct7 struct {
+			Name     string `gorm:"size:70;uniqueIndex:idx_us6_all_names"`
+			NickName string `gorm:"size:70;uniqueIndex:idx_us6_all_names"`
 		}
 	)
-	checkField(&UniqueStruct4{}, "name", false, true)
 	checkField(&UniqueStruct5{}, "name", false, true)
+	checkField(&UniqueStruct6{}, "name", false, true)
 
-	checkField(&UniqueStruct6{}, "name", false, false)
+	checkField(&UniqueStruct7{}, "name", false, false)
-	checkField(&UniqueStruct6{}, "nick_name", false, false)
+	checkField(&UniqueStruct7{}, "nick_name", false, false)
-	checkField(&UniqueStruct6{}, "nick_name", false, false)
+	checkField(&UniqueStruct7{}, "nick_name", false, false)
 
 	type TestCase struct {
 		name      string
@@ -1703,36 +1709,46 @@ func TestMigrateWithUniqueIndexAndUnique(t *testing.T) {
 		checkColumnType(t, "name", true)
 		checkIndex(t, nil)
 	}
-	index := &migrator.Index{
+	uniqueIndex := &migrator.Index{
 		TableName:       table,
 		NameValue:       DB.Config.NamingStrategy.IndexName(table, "name"),
 		ColumnList:      []string{"name"},
 		PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
 		UniqueValue:     sql.NullBool{Bool: true, Valid: true},
 	}
-	if DB.Dialector.Name() != "mysql" {
+	checkUniqueIndex := func(t *testing.T) {
+		checkColumnType(t, "name", false)
+		checkIndex(t, []gorm.Index{uniqueIndex})
+	}
+	if DB.Dialector.Name() == "mysql" {
 		// in mysql, unique equals uniqueIndex
 		checkUnique = func(t *testing.T) {
 			checkColumnType(t, "name", true)
-			checkIndex(t, []gorm.Index{index})
+			checkIndex(t, []gorm.Index{&migrator.Index{
+				TableName:       table,
+				NameValue:       DB.Config.NamingStrategy.UniqueName(table, "name"),
+				ColumnList:      []string{"name"},
+				PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
+				UniqueValue:     sql.NullBool{Bool: true, Valid: true},
+			}})
 		}
+		checkUniqueIndex = func(t *testing.T) {
+			checkColumnType(t, "name", true)
+			checkIndex(t, []gorm.Index{uniqueIndex})
 		}
-	checkUniqueIndex := func(t *testing.T) {
-		checkColumnType(t, "name", false)
-		checkIndex(t, []gorm.Index{index})
 	}
 
 	tests := []TestCase{
-		{name: "notUnique to notUnique", from: &UniqueStruct1{}, to: &UniqueStruct1{}, checkFunc: checkNotUnique},
+		{name: "notUnique to notUnique", from: &UniqueStruct1{}, to: &UniqueStruct2{}, checkFunc: checkNotUnique},
-		{name: "notUnique to unique", from: &UniqueStruct1{}, to: &UniqueStruct2{}, checkFunc: checkUnique},
+		{name: "notUnique to unique", from: &UniqueStruct1{}, to: &UniqueStruct3{}, checkFunc: checkUnique},
-		{name: "notUnique to uniqueIndex", from: &UniqueStruct1{}, to: &UniqueStruct4{}, checkFunc: checkUniqueIndex},
+		{name: "notUnique to uniqueIndex", from: &UniqueStruct1{}, to: &UniqueStruct5{}, checkFunc: checkUniqueIndex},
-		{name: "unique to notUnique", from: &UniqueStruct2{}, to: &UniqueStruct1{}, checkFunc: checkNotUnique},
+		{name: "unique to notUnique", from: &UniqueStruct3{}, to: &UniqueStruct1{}, checkFunc: checkNotUnique},
-		{name: "unique to unique", from: &UniqueStruct2{}, to: &UniqueStruct3{}, checkFunc: checkUnique},
+		{name: "unique to unique", from: &UniqueStruct3{}, to: &UniqueStruct4{}, checkFunc: checkUnique},
-		{name: "unique to uniqueIndex", from: &UniqueStruct2{}, to: &UniqueStruct4{}, checkFunc: checkUniqueIndex},
+		{name: "unique to uniqueIndex", from: &UniqueStruct3{}, to: &UniqueStruct5{}, checkFunc: checkUniqueIndex},
-		{name: "uniqueIndex to notUnique", from: &UniqueStruct4{}, to: &UniqueStruct2{}, checkFunc: checkNotUnique},
+		{name: "uniqueIndex to notUnique", from: &UniqueStruct5{}, to: &UniqueStruct2{}, checkFunc: checkNotUnique},
-		{name: "uniqueIndex to unique", from: &UniqueStruct4{}, to: &UniqueStruct2{}, checkFunc: checkUnique},
+		{name: "uniqueIndex to unique", from: &UniqueStruct5{}, to: &UniqueStruct3{}, checkFunc: checkUnique},
-		{name: "uniqueIndex to uniqueIndex", from: &UniqueStruct4{}, to: &UniqueStruct5{}, checkFunc: checkUniqueIndex},
+		{name: "uniqueIndex to uniqueIndex", from: &UniqueStruct5{}, to: &UniqueStruct6{}, checkFunc: checkUniqueIndex},
-		{name: "uniqueIndex to multi uniqueIndex", from: &UniqueStruct4{}, to: &UniqueStruct6{}, checkFunc: func(t *testing.T) {
+		{name: "uniqueIndex to multi uniqueIndex", from: &UniqueStruct5{}, to: &UniqueStruct7{}, checkFunc: func(t *testing.T) {
 			checkColumnType(t, "name", false)
 			checkColumnType(t, "nick_name", false)
 			checkIndex(t, []gorm.Index{&migrator.Index{