ColumnType() (columnType string, ok bool) // varchar(64)
	PrimaryKey() (isPrimaryKey bool, ok bool)
	AutoIncrement() (isAutoIncrement bool, ok bool)
	Length() (length int64, ok bool)
	DecimalSize() (precision int64, scale int64, ok bool)
	Nullable() (nullable bool, ok bool)
	Unique() (unique bool, ok bool)
	ScanType() reflect.Type
	Comment() (value string, ok bool)
	DefaultValue() (value string, ok bool)
}

	}

	if orderByClause, ok := db.Statement.Clauses["ORDER BY"]; ok {
		if _, ok := db.Statement.Clauses["GROUP BY"]; !ok {
			delete(tx.Statement.Clauses, "ORDER BY")
			defer func() {
				tx.Statement.Clauses["ORDER BY"] = orderByClause
			}()
		}
	}

	tx.Statement.Dest = count
	tx = tx.callbacks.Query().Execute(tx)

	if _, ok := db.Statement.Clauses["GROUP BY"]; ok || tx.RowsAffected != 1 {

func (db *DB) Clauses(conds ...clause.Expression) (tx *DB) {
	tx = db.getInstance()
	var whereConds []interface{}

	for _, cond := range conds {
		if c, ok := cond.(clause.Interface); ok {
			tx.Statement.AddClause(c)
		} else if optimizer, ok := cond.(StatementModifier); ok {
			optimizer.ModifyStatement(tx.Statement)
		} else {
			whereConds = append(whereConds, cond)
		}
	}

	if len(whereConds) > 0 {

}

// ColumnType returns the database type of the column. like `varchar(16)`
func (ct ColumnType) ColumnType() (columnType string, ok bool) {
	return ct.ColumnTypeValue.String, ct.ColumnTypeValue.Valid
}

// PrimaryKey returns the column is primary key or not.
func (ct ColumnType) PrimaryKey() (isPrimaryKey bool, ok bool) {
	return ct.PrimaryKeyValue.Bool, ct.PrimaryKeyValue.Valid
}

func BeforeDelete(db *gorm.DB) {
	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && db.Statement.Schema.BeforeDelete {
		callMethod(db, func(value interface{}, tx *gorm.DB) bool {
			if i, ok := value.(BeforeDeleteInterface); ok {
				db.AddError(i.BeforeDelete(tx))
				return true
			}

			return false
		})
	}
}

func DeleteBeforeAssociations(db *gorm.DB) {
	if db.Error == nil && db.Statement.Schema != nil {

				}
				if v, ok := columnType.Comment(); !ok || v != "my age" {
					t.Fatalf("column age comment should be correct, name: %v, column: %#v", columnType.Name(),
						columnType)
				}
			case "code":
				if v, ok := columnType.Unique(); !ok || !v {
					t.Fatalf("column code unique should be correct, name: %v, column: %#v", columnType.Name(),
						columnType)
				}

	return idx.ColumnList
}

// PrimaryKey returns the index is primary key or not.
func (idx Index) PrimaryKey() (isPrimaryKey bool, ok bool) {
	return idx.PrimaryKeyValue.Bool, idx.PrimaryKeyValue.Valid
}

// Unique returns whether the index is unique or not.
func (idx Index) Unique() (unique bool, ok bool) {
	return idx.UniqueValue.Bool, idx.UniqueValue.Valid
}

// Option return the optional attribute of the index

			t.Errorf("%v: expect: %+v, got %+v", utils.FileWithLineNum(), expect, got)
			return
		}

		if valuer, ok := got.(driver.Valuer); ok {
			got, _ = valuer.Value()
		}

		if valuer, ok := expect.(driver.Valuer); ok {
			expect, _ = valuer.Value()
		}

		if got != nil {
			got = reflect.Indirect(reflect.ValueOf(got)).Interface()
		}

		if expect != nil {

	}

	if len(userSchema.Relationships.Relations) != 1 {
		t.Fatalf("expects 1 relations, but got %v", len(userSchema.Relationships.Relations))
	}

	if createdByRel, ok := userSchema.Relationships.Relations["CreatedBy"]; ok {
		if createdByRel.FieldSchema != userSchema {
			t.Fatalf("expects same field schema, but got new %p, old %p", createdByRel.FieldSchema, userSchema)
		}
	} else {

	}
}

func TestSetAndGet(t *testing.T) {
	if value, ok := DB.Set("hello", "world").Get("hello"); !ok {
		t.Errorf("Should be able to get setting after set")
	} else if value.(string) != "world" {
		t.Errorf("Set value should not be changed")
	}

	if _, ok := DB.Get("non_existing"); ok {
		t.Errorf("Get non existing key should return error")
	}