refactor: distinguish between Unique and UniqueIndex (#156)

* refactor: distinguish between Unique and UniqueIndex

* take care of unique created by old version

* update gorm to master latest (for https://github.com/go-gorm/gorm/pull/6386)

* merge

ddlmod.go

@@ -13,6 +13,7 @@ import (
 
 var (
 	sqliteSeparator    = "`|\"|'|\t"
+	uniqueRegexp       = regexp.MustCompile(fmt.Sprintf(`^CONSTRAINT [%v]?[\w-]+[%v]? UNIQUE (.*)$`, sqliteSeparator, sqliteSeparator))
 	indexRegexp        = regexp.MustCompile(fmt.Sprintf(`(?is)CREATE(?: UNIQUE)? INDEX [%v]?[\w\d-]+[%v]?(?s:.*?)ON (.*)$`, sqliteSeparator, sqliteSeparator))
 	tableRegexp        = regexp.MustCompile(fmt.Sprintf(`(?is)(CREATE TABLE [%v]?[\w\d-]+[%v]?)(?:\s*\((.*)\))?`, sqliteSeparator, sqliteSeparator))
 	separatorRegexp    = regexp.MustCompile(fmt.Sprintf("[%v]", sqliteSeparator))
@@ -103,11 +104,24 @@ func parseDDL(strs ...string) (*ddl, error) {
 
 			for _, f := range result.fields {
 				fUpper := strings.ToUpper(f)
-				if strings.HasPrefix(fUpper, "CHECK") ||
-					strings.HasPrefix(fUpper, "CONSTRAINT") {
+				if strings.HasPrefix(fUpper, "CHECK") {
+					continue
+				}
+				if strings.HasPrefix(fUpper, "CONSTRAINT") {
+					matches := uniqueRegexp.FindStringSubmatch(f)
+					if len(matches) > 0 {
+						if columns := getAllColumns(matches[1]); len(columns) == 1 {
+							for idx, column := range result.columns {
+								if column.NameValue.String == columns[0] {
+									column.UniqueValue = sql.NullBool{Bool: true, Valid: true}
+									result.columns[idx] = column
+									break
+								}
+							}
+						}
+					}
 					continue
 				}
-
 				if strings.HasPrefix(fUpper, "PRIMARY KEY") {
 					for _, name := range getAllColumns(f) {
 						for idx, column := range result.columns {
@@ -159,14 +173,7 @@ func parseDDL(strs ...string) (*ddl, error) {
 				}
 			}
 		} else if matches := indexRegexp.FindStringSubmatch(str); len(matches) > 0 {
-			for _, column := range getAllColumns(matches[1]) {
-				for idx, c := range result.columns {
-					if c.NameValue.String == column {
-						c.UniqueValue = sql.NullBool{Bool: strings.ToUpper(strings.Fields(str)[1]) == "UNIQUE", Valid: true}
-						result.columns[idx] = c
-					}
-				}
-			}
+			// don't report Unique by UniqueIndex
 		} else {
 			return nil, errors.New("invalid DDL")
 		}
@@ -268,20 +275,6 @@ func (d *ddl) getColumns() []string {
 	return res
 }
 
-func (d *ddl) alterColumn(name, sql string) bool {
-	reg := regexp.MustCompile("^(`|'|\"| )" + regexp.QuoteMeta(name) + "(`|'|\"| ) .*?$")
-
-	for i := 0; i < len(d.fields); i++ {
-		if reg.MatchString(d.fields[i]) {
-			d.fields[i] = sql
-			return false
-		}
-	}
-
-	d.fields = append(d.fields, sql)
-	return true
-}
-
 func (d *ddl) removeColumn(name string) bool {
 	reg := regexp.MustCompile("^(`|'|\"| )" + regexp.QuoteMeta(name) + "(`|'|\"| ) .*?$")
 

ddlmod_test.go

@@ -16,11 +16,12 @@ func TestParseDDL(t *testing.T) {
 		columns []migrator.ColumnType
 	}{
 		{"with_fk", []string{
-			"CREATE TABLE `notes` (`id` integer NOT NULL,`text` varchar(500) DEFAULT \"hello\",`age` integer DEFAULT 18,`user_id` integer,PRIMARY KEY (`id`),CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))",
+			"CREATE TABLE `notes` (" +
+				"`id` integer NOT NULL,`text` varchar(500) DEFAULT \"hello\",`age` integer DEFAULT 18,`user_id` integer,PRIMARY KEY (`id`),CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))",
 			"CREATE UNIQUE INDEX `idx_profiles_refer` ON `profiles`(`text`)",
 		}, 6, []migrator.ColumnType{
 			{NameValue: sql.NullString{String: "id", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, PrimaryKeyValue: sql.NullBool{Bool: true, Valid: true}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, DefaultValueValue: sql.NullString{Valid: false}},
-			{NameValue: sql.NullString{String: "text", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 500, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(500)", Valid: true}, DefaultValueValue: sql.NullString{String: "hello", Valid: true}, NullableValue: sql.NullBool{Bool: true, Valid: true}, UniqueValue: sql.NullBool{Bool: true, Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "text", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 500, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(500)", Valid: true}, DefaultValueValue: sql.NullString{String: "hello", Valid: true}, NullableValue: sql.NullBool{Bool: true, Valid: true}, UniqueValue: sql.NullBool{Bool: false, Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
 			{NameValue: sql.NullString{String: "age", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, DefaultValueValue: sql.NullString{String: "18", Valid: true}, NullableValue: sql.NullBool{Bool: true, Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
 			{NameValue: sql.NullString{String: "user_id", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, NullableValue: sql.NullBool{Bool: true, Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
 		},
@@ -56,28 +57,54 @@ func TestParseDDL(t *testing.T) {
 					ColumnTypeValue:   sql.NullString{String: "int", Valid: true},
 					NullableValue:     sql.NullBool{Bool: false, Valid: true},
 					DefaultValueValue: sql.NullString{Valid: false},
-					UniqueValue:       sql.NullBool{Bool: true, Valid: true},
+					UniqueValue:       sql.NullBool{Bool: false, Valid: true},
 					PrimaryKeyValue:   sql.NullBool{Valid: true},
 				},
 			},
-		},
-		{
+		}, {
 			"unique index",
 			[]string{
 				"CREATE TABLE `test-b` (`field` integer NOT NULL)",
 				"CREATE UNIQUE INDEX `idx_uq` ON `test-b`(`field`) WHERE field = 0",
 			},
 			1,
-			[]migrator.ColumnType{
-				{
+			[]migrator.ColumnType{{
 				NameValue:       sql.NullString{String: "field", Valid: true},
 				DataTypeValue:   sql.NullString{String: "integer", Valid: true},
 				ColumnTypeValue: sql.NullString{String: "integer", Valid: true},
 				PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
-					UniqueValue:     sql.NullBool{Bool: true, Valid: true},
+				UniqueValue:     sql.NullBool{Bool: false, Valid: true},
 				NullableValue:   sql.NullBool{Bool: false, Valid: true},
+			}},
+		}, {
+			"normal index",
+			[]string{
+				"CREATE TABLE `test-c` (`field` integer NOT NULL)",
+				"CREATE INDEX `idx_uq` ON `test-c`(`field`)",
 			},
+			1,
+			[]migrator.ColumnType{{
+				NameValue:       sql.NullString{String: "field", Valid: true},
+				DataTypeValue:   sql.NullString{String: "integer", Valid: true},
+				ColumnTypeValue: sql.NullString{String: "integer", Valid: true},
+				PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
+				UniqueValue:     sql.NullBool{Bool: false, Valid: true},
+				NullableValue:   sql.NullBool{Bool: false, Valid: true},
+			}},
+		}, {
+			"unique constraint",
+			[]string{
+				"CREATE TABLE `unique_struct` (`name` text,CONSTRAINT `uni_unique_struct_name` UNIQUE (`name`))",
 			},
+			2,
+			[]migrator.ColumnType{{
+				NameValue:       sql.NullString{String: "name", Valid: true},
+				DataTypeValue:   sql.NullString{String: "text", Valid: true},
+				ColumnTypeValue: sql.NullString{String: "text", Valid: true},
+				PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
+				UniqueValue:     sql.NullBool{Bool: true, Valid: true},
+				NullableValue:   sql.NullBool{Bool: true, Valid: true},
+			}},
 		},
 		{
 			"non-unique index",

go.mod

@@ -4,7 +4,7 @@ go 1.20
 
 require (
 	github.com/mattn/go-sqlite3 v1.14.17
-	gorm.io/gorm v1.25.2-0.20230530020048-26663ab9bf55
+	gorm.io/gorm v1.25.7-0.20240204074919-46816ad31dde
 )
 
 require (

go.sum

@@ -8,3 +8,5 @@ gorm.io/gorm v1.25.0 h1:+KtYtb2roDz14EQe4bla8CbQlmb9dN3VejSai3lprfU=
 gorm.io/gorm v1.25.0/go.mod h1:L4uxeKpfBml98NYqVqwAdmV1a2nBtAec/cf3fpucW/k=
 gorm.io/gorm v1.25.2-0.20230530020048-26663ab9bf55 h1:sC1Xj4TYrLqg1n3AN10w871An7wJM0gzgcm8jkIkECQ=
 gorm.io/gorm v1.25.2-0.20230530020048-26663ab9bf55/go.mod h1:L4uxeKpfBml98NYqVqwAdmV1a2nBtAec/cf3fpucW/k=
+gorm.io/gorm v1.25.7-0.20240204074919-46816ad31dde h1:9DShaph9qhkIYw7QF91I/ynrr4cOO2PZra2PFD7Mfeg=
+gorm.io/gorm v1.25.7-0.20240204074919-46816ad31dde/go.mod h1:hbnx/Oo0ChWMn1BIhpy1oYozzpM15i4YPuHDmfYtwg8=

migrator.go

@@ -79,14 +79,28 @@ func (m Migrator) AlterColumn(value interface{}, name string) error {
 	return m.RunWithoutForeignKey(func() error {
 		return m.recreateTable(value, nil, func(ddl *ddl, stmt *gorm.Statement) (*ddl, []interface{}, error) {
 			if field := stmt.Schema.LookUpField(name); field != nil {
-				if ddl.alterColumn(field.DBName, fmt.Sprintf("`%s` ?", field.DBName)) {
-					return nil, nil, fmt.Errorf("field `%s` not found in origin ddl, ddl= '%s'", name, ddl.compile())
+				var sqlArgs []interface{}
+				for i, f := range ddl.fields {
+					if matches := columnRegexp.FindStringSubmatch(f); len(matches) > 1 && matches[1] == field.DBName {
+						ddl.fields[i] = fmt.Sprintf("`%v` ?", field.DBName)
+						sqlArgs = []interface{}{m.FullDataTypeOf(field)}
+						// table created by old version might look like `CREATE TABLE ? (? varchar(10) UNIQUE)`.
+						// FullDataTypeOf doesn't contain UNIQUE, so we need to add unique constraint.
+						if strings.Contains(strings.ToUpper(matches[3]), " UNIQUE") {
+							uniName := m.DB.NamingStrategy.UniqueName(stmt.Table, field.DBName)
+							uni, _ := m.GuessConstraintInterfaceAndTable(stmt, uniName)
+							if uni != nil {
+								uniSQL, uniArgs := uni.Build()
+								ddl.addConstraint(uniName, uniSQL)
+								sqlArgs = append(sqlArgs, uniArgs...)
 							}
-
-				return ddl, []interface{}{m.FullDataTypeOf(field)}, nil
 						}
-
-			return nil, nil, fmt.Errorf("failed to alter field with name `%s`", name)
+						break
+					}
+				}
+				return ddl, sqlArgs, nil
+			}
+			return nil, nil, fmt.Errorf("failed to alter field with name %v", name)
 		})
 	})
 }
@@ -153,7 +167,7 @@ func (m Migrator) DropColumn(value interface{}, name string) error {
 
 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.GuessConstraintInterfaceAndTable(stmt, name)
 
 		return m.recreateTable(value, &table,
 			func(ddl *ddl, stmt *gorm.Statement) (*ddl, []interface{}, error) {
@@ -164,12 +178,8 @@ func (m Migrator) CreateConstraint(value interface{}, name string) error {
 				)
 
 				if constraint != nil {
-					constraintName = constraint.Name
-					constraintSql, constraintValues = buildConstraint(constraint)
-				} else if chk != nil {
-					constraintName = chk.Name
-					constraintSql = "CONSTRAINT ? CHECK (?)"
-					constraintValues = []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
+					constraintName = constraint.GetName()
+					constraintSql, constraintValues = constraint.Build()
 				} else {
 					return nil, nil, nil
 				}
@@ -182,11 +192,9 @@ func (m Migrator) CreateConstraint(value interface{}, name string) error {
 
 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.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
-		} else if chk != nil {
-			name = chk.Name
+			name = constraint.GetName()
 		}
 
 		return m.recreateTable(value, &table,
@@ -200,11 +208,9 @@ func (m Migrator) DropConstraint(value interface{}, name string) error {
 func (m Migrator) HasConstraint(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
-		} else if chk != nil {
-			name = chk.Name
+			name = constraint.GetName()
 		}
 
 		m.DB.Raw(
@@ -317,26 +323,44 @@ func (m Migrator) DropIndex(value interface{}, name string) error {
 	})
 }
 
-func buildConstraint(constraint *schema.Constraint) (sql string, results []interface{}) {
-	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
-	if constraint.OnDelete != "" {
-		sql += " ON DELETE " + constraint.OnDelete
-	}
+type Index struct {
+	Seq     int
+	Name    string
+	Unique  bool
+	Origin  string
+	Partial bool
+}
 
-	if constraint.OnUpdate != "" {
-		sql += " ON UPDATE " + constraint.OnUpdate
+// GetIndexes return Indexes []gorm.Index and execErr error,
+// See the [doc]
+//
+// [doc]: https://www.sqlite.org/pragma.html#pragma_index_list
+func (m Migrator) GetIndexes(value interface{}) ([]gorm.Index, error) {
+	indexes := make([]gorm.Index, 0)
+	err := m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		rst := make([]*Index, 0)
+		if err := m.DB.Debug().Raw(fmt.Sprintf("PRAGMA index_list(%q)", stmt.Table)).Scan(&rst).Error; err != nil {
+			return err
 		}
-
-	var foreignKeys, references []interface{}
-	for _, field := range constraint.ForeignKeys {
-		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
+		for _, index := range rst {
+			if index.Origin == "u" { // skip the index was created by a UNIQUE constraint
+				continue
 			}
-
-	for _, field := range constraint.References {
-		references = append(references, clause.Column{Name: field.DBName})
+			var columns []string
+			if err := m.DB.Raw(fmt.Sprintf("SELECT name from PRAGMA_index_info(%q)", index.Name)).Scan(&columns).Error; err != nil { // alias `PRAGMA index_info(?)`
+				return err
 			}
-	results = append(results, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
-	return
+			indexes = append(indexes, &migrator.Index{
+				TableName:       stmt.Table,
+				NameValue:       index.Name,
+				ColumnList:      columns,
+				PrimaryKeyValue: sql.NullBool{Bool: index.Origin == "pk", Valid: true}, // The exceptions are INTEGER PRIMARY KEY
+				UniqueValue:     sql.NullBool{Bool: index.Unique, Valid: true},
+			})
+		}
+		return nil
+	})
+	return indexes, err
 }
 
 func (m Migrator) getRawDDL(table string) (string, error) {