},
		{
			[]clause.Interface{clause.Select{
				Columns: []clause.Column{clause.PrimaryColumn},
			}, clause.From{}},
			"SELECT `users`.`id` FROM `users`", nil,
		},
		{
			[]clause.Interface{clause.Select{
				Columns: []clause.Column{clause.PrimaryColumn},
			}, clause.Select{
				Columns: []clause.Column{{Name: "name"}},
			}, clause.From{}},
			"SELECT `name` FROM `users`", nil,
		},
		{

						queryConds = append(queryConds, clause.Eq{
							Column: clause.Column{Table: rel.JoinTable.Table, Name: ref.ForeignKey.DBName},
							Value:  ref.PrimaryValue,
						})
					}
				}

				_, foreignValues := schema.GetIdentityFieldValuesMap(db.Statement.Context, db.Statement.ReflectValue, foreignFields)
				column, values := schema.ToQueryValues(table, relForeignKeys, foreignValues)

				[]clause.Column{clause.PrimaryColumn},
			}, clause.Returning{}, clause.Returning{
				[]clause.Column{{Name: "name"}, {Name: "age"}},
			}},
			"SELECT * FROM `users` RETURNING *", nil,
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Returning{
				[]clause.Column{clause.PrimaryColumn},
			}, clause.Returning{
				[]clause.Column{{Name: "name"}, {Name: "age"}},

			clause.Eq{Column: column, Value: (*string)(nil)},
			clause.Eq{Column: column, Value: (*int)(nil)},
			clause.Eq{Column: column, Value: (*bool)(nil)},
			clause.Eq{Column: column, Value: (interface{})(nil)},
			clause.Eq{Column: column, Value: sql.NullString{String: "", Valid: false}},
		},
		Result: "`column-name` IS NULL",
	}, {
		Expressions: []clause.Expression{

				Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},
			}},
			"SELECT * FROM `users` ORDER BY `users`.`id` DESC", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{}, clause.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},
				}, clause.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.Column{Name: "name"}}},
				},
			},

			}},
			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?",
			[]interface{}{"1", "jinzhu", 18},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{

}

// AutoIncrement returns the column is auto increment or not.
func (ct ColumnType) AutoIncrement() (isAutoIncrement bool, ok bool) {
	return ct.AutoIncrementValue.Bool, ct.AutoIncrementValue.Valid
}

// Length returns the column type length for variable length column types
func (ct ColumnType) Length() (length int64, ok bool) {
	if ct.LengthValue.Valid {
		return ct.LengthValue.Int64, true
	}
	return ct.SQLColumnType.Length()
}

							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.UnixNano()})
						} else if field.AutoUpdateTime == schema.UnixMillisecond {
							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.UnixMilli()})
						} else if field.AutoUpdateTime == schema.UnixSecond {
							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.Unix()})

			clause.Where{Exprs: []clause.Expression{
				clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
				clause.Gt{Column: "age", Value: 18},
				clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}),
			}},
			clause.Where{Exprs: []clause.Expression{
				clause.Or(clause.Gt{Column: "score", Value: 100}, clause.Like{Column: "name", Value: "%linus%"}),
			}},

type GroupBy struct {
	Columns []Column
	Having  []Expression
}

// Name from clause name
func (groupBy GroupBy) Name() string {
	return "GROUP BY"
}

// Build build group by clause
func (groupBy GroupBy) Build(builder Builder) {
	for idx, column := range groupBy.Columns {
		if idx > 0 {
			builder.WriteByte(',')
		}

		builder.WriteQuoted(column)
	}

	if len(groupBy.Having) > 0 {