package gorm

import (
	"reflect"

	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
)

// Migrator returns migrator
func (db *DB) Migrator() Migrator {
	tx := db.getInstance()

	// apply scopes to migrator
	for len(tx.Statement.scopes) > 0 {
		tx = tx.executeScopes()
	}

	return tx.Dialector.Migrator(tx.Session(&Session{}))
}

// AutoMigrate run auto migration for given models

import (
	"context"
	"database/sql"

	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
)

// Dialector GORM database dialector
type Dialector interface {
	Name() string
	Initialize(*DB) error
	Migrator(db *DB) Migrator
	DataTypeOf(*schema.Field) string
	DefaultValueOf(*schema.Field) clause.Expression
	BindVarTo(writer clause.Writer, stmt *Statement, v interface{})
	QuoteTo(clause.Writer, string)

		LastInsertIDReversed: true,
	})

	return nil
}

func (DummyDialector) DefaultValueOf(field *schema.Field) clause.Expression {
	return clause.Expr{SQL: "DEFAULT"}
}

func (DummyDialector) Migrator(*gorm.DB) gorm.Migrator {
	return nil
}

func (DummyDialector) BindVarTo(writer clause.Writer, stmt *gorm.Statement, v interface{}) {
	writer.WriteByte('?')
}

package migrator

import (
	"database/sql"
)

// TableType table type implements TableType interface
type TableType struct {
	SchemaValue  string
	NameValue    string
	TypeValue    string
	CommentValue sql.NullString
}

// Schema returns the schema of the table.
func (ct TableType) Schema() string {
	return ct.SchemaValue
}

// Name returns the name of the table.
func (ct TableType) Name() string {

package migrator

import "database/sql"

// Index implements gorm.Index interface
type Index struct {
	TableName       string
	NameValue       string
	ColumnList      []string
	PrimaryKeyValue sql.NullBool
	UniqueValue     sql.NullBool
	OptionValue     string
}

// Table return the table name of the index.
func (idx Index) Table() string {
	return idx.TableName
}

// Name return the name of the index.

	if DB.Dialector.Name() != "postgres" {
		t.Skip()
	}

	type Thing struct {
		gorm.Model
		SomeID  string
		OtherID string
		Data    string
	}

	DB.Migrator().DropTable(&Thing{})
	DB.Migrator().CreateTable(&Thing{})
	if err := DB.Exec("ALTER TABLE things ADD CONSTRAINT some_id_other_id_unique UNIQUE (some_id, other_id)").Error; err != nil {
		t.Error(err)
	}

	thing := Thing{

func (d testDialector) Name() string                                   { return "test" }
func (d testDialector) Initialize(*gorm.DB) error                      { return nil }
func (d testDialector) Migrator(db *gorm.DB) gorm.Migrator             { return nil }
func (d testDialector) DataTypeOf(*schema.Field) string                { return "" }
func (d testDialector) DefaultValueOf(*schema.Field) clause.Expression { return clause.Expr{} }

	if DB.Dialector.Name() != "gaussdb" {
		t.Skip()
	}

	type Thing struct {
		gorm.Model
		SomeID  string
		OtherID string
		Data    string
	}

	DB.Migrator().DropTable(&Thing{})
	DB.Migrator().CreateTable(&Thing{})
	if err := DB.Exec("ALTER TABLE things ADD CONSTRAINT some_id_other_id_unique UNIQUE (some_id, other_id)").Error; err != nil {
		t.Error(err)
	}

	thing := Thing{

package migrator

import (
	"database/sql"
	"reflect"
)

// ColumnType column type implements ColumnType interface
type ColumnType struct {
	SQLColumnType      *sql.ColumnType
	NameValue          sql.NullString
	DataTypeValue      sql.NullString
	ColumnTypeValue    sql.NullString
	PrimaryKeyValue    sql.NullBool
	UniqueValue        sql.NullBool
	AutoIncrementValue sql.NullBool
	LengthValue        sql.NullInt64

		t.Errorf("should returns record not found error, but got %v", err)
	}
}

func TestDeleteWithTable(t *testing.T) {
	type UserWithDelete struct {
		gorm.Model
		Name string
	}

	DB.Table("deleted_users").Migrator().DropTable(UserWithDelete{})
	DB.Table("deleted_users").AutoMigrate(UserWithDelete{})

	user := UserWithDelete{Name: "delete1"}
	DB.Table("deleted_users").Create(&user)

	var result UserWithDelete