modify unique to constraint

migrator/migrator.go

@@ -82,10 +82,6 @@ func (m Migrator) FullDataTypeOf(field *schema.Field) (expr clause.Expr) {
 		expr.SQL += " NOT NULL"
 	}
 
-	if field.Unique {
-		expr.SQL += " UNIQUE"
-	}
-
 	if field.HasDefaultValue && (field.DefaultValueInterface != nil || field.DefaultValue != "") {
 		if field.DefaultValueInterface != nil {
 			defaultStmt := &gorm.Statement{Vars: []interface{}{field.DefaultValueInterface}}
@@ -119,8 +115,9 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 					return err
 				}
 				var (
-					parseIndexes          = stmt.Schema.ParseIndexes()
+					parseIndexes           = stmt.Schema.ParseIndexes()
-					parseCheckConstraints = stmt.Schema.ParseCheckConstraints()
+					parseCheckConstraints  = stmt.Schema.ParseCheckConstraints()
+					parseUniqueConstraints = stmt.Schema.ParseUniqueConstraints()
 				)
 				for _, dbName := range stmt.Schema.DBNames {
 					var foundColumn gorm.ColumnType
@@ -160,6 +157,14 @@ 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 {
@@ -257,7 +262,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 					}
 					if constraint := rel.ParseConstraint(); constraint != nil {
 						if constraint.Schema == stmt.Schema {
-							sql, vars := buildConstraint(constraint)
+							sql, vars := constraint.Build()
 							createTableSQL += sql + ","
 							values = append(values, vars...)
 						}
@@ -265,6 +270,11 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				}
 			}
 
+			for _, uni := range stmt.Schema.ParseUniqueConstraints() {
+				createTableSQL += "CONSTRAINT ? UNIQUE (?),"
+				values = append(values, clause.Column{Name: uni.Name}, clause.Expr{SQL: stmt.Quote(uni.Field.DBName)})
+			}
+
 			for _, chk := range stmt.Schema.ParseCheckConstraints() {
 				createTableSQL += "CONSTRAINT ? CHECK (?),"
 				values = append(values, clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint})
@@ -599,37 +609,20 @@ func (m Migrator) DropView(name string) error {
 	return m.DB.Exec("DROP VIEW IF EXISTS ?", clause.Table{Name: name}).Error
 }
 
-func buildConstraint(constraint *schema.Constraint) (sql string, results []interface{}) {
-	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
-	if constraint.OnDelete != "" {
-		sql += " ON DELETE " + constraint.OnDelete
-	}
-
-	if constraint.OnUpdate != "" {
-		sql += " ON UPDATE " + constraint.OnUpdate
-	}
-
-	var foreignKeys, references []interface{}
-	for _, field := range constraint.ForeignKeys {
-		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
-	}
-
-	for _, field := range constraint.References {
-		references = append(references, clause.Column{Name: field.DBName})
-	}
-	results = append(results, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
-	return
-}
-
 // GuessConstraintAndTable guess statement's constraint and it's table based on name
-func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_ *schema.Constraint, _ *schema.Check, table string) {
+func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_ schema.ConstraintInterface, table string) {
 	if stmt.Schema == nil {
-		return nil, nil, stmt.Table
+		return nil, stmt.Table
 	}
 
 	checkConstraints := stmt.Schema.ParseCheckConstraints()
 	if chk, ok := checkConstraints[name]; ok {
-		return nil, &chk, stmt.Table
+		return &chk, stmt.Table
+	}
+
+	uniqueConstraints := stmt.Schema.ParseUniqueConstraints()
+	if uni, ok := uniqueConstraints[name]; ok {
+		return &uni, stmt.Table
 	}
 
 	getTable := func(rel *schema.Relationship) string {
@@ -644,7 +637,7 @@ func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_
 
 	for _, rel := range stmt.Schema.Relationships.Relations {
 		if constraint := rel.ParseConstraint(); constraint != nil && constraint.Name == name {
-			return constraint, nil, getTable(rel)
+			return constraint, getTable(rel)
 		}
 	}
 
@@ -652,40 +645,39 @@ func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_
 		for k := range checkConstraints {
 			if checkConstraints[k].Field == field {
 				v := checkConstraints[k]
-				return nil, &v, stmt.Table
+				return &v, stmt.Table
+			}
+		}
+
+		for k := range uniqueConstraints {
+			if uniqueConstraints[k].Field == field {
+				v := uniqueConstraints[k]
+				return &v, stmt.Table
 			}
 		}
 
 		for _, rel := range stmt.Schema.Relationships.Relations {
 			if constraint := rel.ParseConstraint(); constraint != nil && rel.Field == field {
-				return constraint, nil, getTable(rel)
+				return constraint, getTable(rel)
 			}
 		}
 	}
 
-	return nil, nil, stmt.Schema.Table
+	return nil, stmt.Schema.Table
 }
 
 // CreateConstraint create constraint
 func (m Migrator) CreateConstraint(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintAndTable(stmt, name)
-		if chk != nil {
-			return m.DB.Exec(
-				"ALTER TABLE ? ADD CONSTRAINT ? CHECK (?)",
-				m.CurrentTable(stmt), clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint},
-			).Error
-		}
-
 		if constraint != nil {
 			vars := []interface{}{clause.Table{Name: table}}
 			if stmt.TableExpr != nil {
 				vars[0] = stmt.TableExpr
 			}
-			sql, values := buildConstraint(constraint)
+			sql, values := constraint.Build()
 			return m.DB.Exec("ALTER TABLE ? ADD "+sql, append(vars, values...)...).Error
 		}
-
 		return nil
 	})
 }
@@ -693,11 +685,9 @@ 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, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
+			name = constraint.GetName()
-		} else if chk != nil {
-			name = chk.Name
 		}
 		return m.DB.Exec("ALTER TABLE ? DROP CONSTRAINT ?", clause.Table{Name: table}, clause.Column{Name: name}).Error
 	})
@@ -708,11 +698,9 @@ 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, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
+			name = constraint.GetName()
-		} else if chk != nil {
-			name = chk.Name
 		}
 
 		return m.DB.Raw(

schema/check.go

@@ -1,35 +0,0 @@
-package schema
-
-import (
-	"regexp"
-	"strings"
-)
-
-// reg match english letters and midline
-var regEnLetterAndMidline = regexp.MustCompile("^[A-Za-z-_]+$")
-
-type Check struct {
-	Name       string
-	Constraint string // length(phone) >= 10
-	*Field
-}
-
-// ParseCheckConstraints parse schema check constraints
-func (schema *Schema) ParseCheckConstraints() map[string]Check {
-	checks := map[string]Check{}
-	for _, field := range schema.FieldsByDBName {
-		if chk := field.TagSettings["CHECK"]; chk != "" {
-			names := strings.Split(chk, ",")
-			if len(names) > 1 && regEnLetterAndMidline.MatchString(names[0]) {
-				checks[names[0]] = Check{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
-			} else {
-				if names[0] == "" {
-					chk = strings.Join(names[1:], ",")
-				}
-				name := schema.namer.CheckerName(schema.Table, field.DBName)
-				checks[name] = Check{Name: name, Constraint: chk, Field: field}
-			}
-		}
-	}
-	return checks
-}

schema/constraint.go

@@ -0,0 +1,66 @@
+package schema
+
+import (
+	"regexp"
+	"strings"
+
+	"gorm.io/gorm/clause"
+)
+
+// reg match english letters and midline
+var regEnLetterAndMidline = regexp.MustCompile("^[A-Za-z-_]+$")
+
+type CheckConstraint struct {
+	Name       string
+	Constraint string // length(phone) >= 10
+	*Field
+}
+
+func (chk *CheckConstraint) GetName() string { return chk.Name }
+
+func (chk *CheckConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
+}
+
+// ParseCheckConstraints parse schema check constraints
+func (schema *Schema) ParseCheckConstraints() map[string]CheckConstraint {
+	checks := map[string]CheckConstraint{}
+	for _, field := range schema.FieldsByDBName {
+		if chk := field.TagSettings["CHECK"]; chk != "" {
+			names := strings.Split(chk, ",")
+			if len(names) > 1 && regEnLetterAndMidline.MatchString(names[0]) {
+				checks[names[0]] = CheckConstraint{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
+			} else {
+				if names[0] == "" {
+					chk = strings.Join(names[1:], ",")
+				}
+				name := schema.namer.CheckerName(schema.Table, field.DBName)
+				checks[name] = CheckConstraint{Name: name, Constraint: chk, Field: field}
+			}
+		}
+	}
+	return checks
+}
+
+type UniqueConstraint struct {
+	Name  string
+	Field *Field
+}
+
+func (uni *UniqueConstraint) GetName() string { return uni.Name }
+
+func (uni *UniqueConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? UNIQUE (?)", []interface{}{clause.Column{Name: uni.Name}, clause.Column{Name: uni.Field.DBName}}
+}
+
+// ParseUniqueConstraints parse schema unique constraints
+func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
+	uniques := make(map[string]UniqueConstraint)
+	for _, field := range schema.Fields {
+		if field.Unique {
+			name := schema.namer.UniqueName(schema.Table, field.DBName)
+			uniques[name] = UniqueConstraint{Name: name, Field: field}
+		}
+	}
+	return uniques
+}

schema/constraint_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils/tests"
 )
 
 type UserCheck struct {
@@ -20,7 +21,7 @@ func TestParseCheck(t *testing.T) {
 		t.Fatalf("failed to parse user check, got error %v", err)
 	}
 
-	results := map[string]schema.Check{
+	results := map[string]schema.CheckConstraint{
 		"name_checker": {
 			Name:       "name_checker",
 			Constraint: "name <> 'jinzhu'",
@@ -53,3 +54,31 @@ func TestParseCheck(t *testing.T) {
 		}
 	}
 }
+
+func TestParseUniqueConstraints(t *testing.T) {
+	type UserUnique struct {
+		Name1 string `gorm:"unique"`
+		Name2 string `gorm:"uniqueIndex"`
+	}
+
+	user, err := schema.Parse(&UserUnique{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse user unique, got error %v", err)
+	}
+	constraints := user.ParseUniqueConstraints()
+
+	results := map[string]schema.UniqueConstraint{
+		"uni_user_uniques_name1": {
+			Name:  "uni_user_uniques_name1",
+			Field: &schema.Field{Name: "Name1", Unique: true},
+		},
+	}
+	for k, result := range results {
+		v, ok := constraints[k]
+		if !ok {
+			t.Errorf("Failed to found unique constraint %v from parsed constraints %+v", k, constraints)
+		}
+		tests.AssertObjEqual(t, result, v, "Name")
+		tests.AssertObjEqual(t, result.Field, v.Field, "Name", "Unique", "UniqueIndex")
+	}
+}

schema/interfaces.go

@@ -4,6 +4,12 @@ import (
 	"gorm.io/gorm/clause"
 )
 
+// ConstraintInterface database constraint interface
+type ConstraintInterface interface {
+	GetName() string
+	Build() (sql string, vars []interface{})
+}
+
 // GormDataTypeInterface gorm data type interface
 type GormDataTypeInterface interface {
 	GormDataType() string

schema/naming.go

@@ -19,6 +19,7 @@ type Namer interface {
 	RelationshipFKName(Relationship) string
 	CheckerName(table, column string) string
 	IndexName(table, column string) string
+	UniqueName(table, column string) string
 }
 
 // Replacer replacer interface like strings.Replacer
@@ -85,6 +86,11 @@ func (ns NamingStrategy) IndexName(table, column string) string {
 	return ns.formatName("idx", table, ns.toDBName(column))
 }
 
+// UniqueName generate unique constraint name
+func (ns NamingStrategy) UniqueName(table, column string) string {
+	return ns.formatName("uni", table, ns.toDBName(column))
+}
+
 func (ns NamingStrategy) formatName(prefix, table, name string) string {
 	formattedName := strings.ReplaceAll(strings.Join([]string{
 		prefix, table, name,

schema/relationship.go

@@ -566,7 +566,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	}
 }
 
-type Constraint struct {
+type FKConstraint struct {
 	Name            string
 	Field           *Field
 	Schema          *Schema
@@ -577,7 +577,31 @@ type Constraint struct {
 	OnUpdate        string
 }
 
-func (rel *Relationship) ParseConstraint() *Constraint {
+func (constraint *FKConstraint) GetName() string { return constraint.Name }
+
+func (constraint *FKConstraint) Build() (sql string, vars []interface{}) {
+	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
+	if constraint.OnDelete != "" {
+		sql += " ON DELETE " + constraint.OnDelete
+	}
+
+	if constraint.OnUpdate != "" {
+		sql += " ON UPDATE " + constraint.OnUpdate
+	}
+
+	var foreignKeys, references []interface{}
+	for _, field := range constraint.ForeignKeys {
+		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
+	}
+
+	for _, field := range constraint.References {
+		references = append(references, clause.Column{Name: field.DBName})
+	}
+	vars = append(vars, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
+	return
+}
+
+func (rel *Relationship) ParseConstraint() *FKConstraint {
 	str := rel.Field.TagSettings["CONSTRAINT"]
 	if str == "-" {
 		return nil
@@ -617,7 +641,7 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 		name = rel.Schema.namer.RelationshipFKName(*rel)
 	}
 
-	constraint := Constraint{
+	constraint := FKConstraint{
 		Name:     name,
 		Field:    rel.Field,
 		OnUpdate: settings["ONUPDATE"],