// GetColDefaultValue gets default value of the column.
func GetColDefaultValue(ctx context.Context, col *model.ColumnInfo) (interface{}, bool, error) {
// Check no default value flag.
if mysql.HasNoDefaultValueFlag(col.Flag) && col.Tp != mysql.TypeEnum {
return nil, false, errors.Errorf("Field '%s' doesn't have a default value", col.Name)
}
// Check and get timestamp/datetime default value.
if col.Tp == mysql.TypeTimestamp || col.Tp == mysql.TypeDatetime {
if col.DefaultValue == nil {
return nil, true, nil
}
value, err := expression.GetTimeValue(ctx, col.DefaultValue, col.Tp, col.Decimal)
if err != nil {
return nil, true, errors.Errorf("Field '%s' get default value fail - %s", col.Name, errors.Trace(err))
}
return value, true, nil
} else if col.Tp == mysql.TypeEnum {
// For enum type, if no default value and not null is set,
// the default value is the first element of the enum list
if col.DefaultValue == nil && mysql.HasNotNullFlag(col.Flag) {
return col.FieldType.Elems[0], true, nil
}
}
return col.DefaultValue, true, nil
}
// getColDefaultValue gets default value of the column.
func getColDefaultValue(col *model.ColumnInfo) (interface{}, bool, error) {
// Check no default value flag.
if mysql.HasNoDefaultValueFlag(col.Flag) && col.Tp != mysql.TypeEnum {
return nil, false, errors.Errorf("Field '%s' doesn't have a default value", col.Name)
}
// Check and get timestamp/datetime default value.
if col.Tp == mysql.TypeEnum {
// For enum type, if no default value and not null is set,
// the default value is the first element of the enum list
if col.DefaultValue == nil && mysql.HasNotNullFlag(col.Flag) {
return col.FieldType.Elems[0], true, nil
}
}
return col.DefaultValue, true, nil
}
// NewColDesc returns a new ColDesc for a column.
func NewColDesc(col *Column) *ColDesc {
// TODO: if we have no primary key and a unique index which's columns are all not null
// we will set these columns' flag as PriKeyFlag
// see https://dev.mysql.com/doc/refman/5.7/en/show-columns.html
// create table
name := col.Name
nullFlag := "YES"
if mysql.HasNotNullFlag(col.Flag) {
nullFlag = "NO"
}
keyFlag := ""
if mysql.HasPriKeyFlag(col.Flag) {
keyFlag = "PRI"
} else if mysql.HasUniKeyFlag(col.Flag) {
keyFlag = "UNI"
} else if mysql.HasMultipleKeyFlag(col.Flag) {
keyFlag = "MUL"
}
var defaultValue interface{}
if !mysql.HasNoDefaultValueFlag(col.Flag) {
defaultValue = col.DefaultValue
}
extra := ""
if mysql.HasAutoIncrementFlag(col.Flag) {
extra = "auto_increment"
} else if mysql.HasOnUpdateNowFlag(col.Flag) {
extra = "on update CURRENT_TIMESTAMP"
}
return &ColDesc{
Field: name.O,
Type: col.GetTypeDesc(),
Collation: col.Collate,
Null: nullFlag,
Key: keyFlag,
DefaultValue: defaultValue,
Extra: extra,
Privileges: defaultPrivileges,
Comment: "",
}
}
// GetColDefaultValue gets default value of the column.
func GetColDefaultValue(ctx context.Context, col *model.ColumnInfo) (types.Datum, bool, error) {
// Check no default value flag.
if mysql.HasNoDefaultValueFlag(col.Flag) && col.Tp != mysql.TypeEnum {
err := errNoDefaultValue.Gen("Field '%s' doesn't have a default value", col.Name)
if ctx != nil {
sessVars := variable.GetSessionVars(ctx)
if !sessVars.StrictSQLMode {
// TODO: add warning.
return GetZeroValue(col), true, nil
}
}
return types.Datum{}, false, errors.Trace(err)
}
// Check and get timestamp/datetime default value.
if col.Tp == mysql.TypeTimestamp || col.Tp == mysql.TypeDatetime {
if col.DefaultValue == nil {
return types.Datum{}, true, nil
}
value, err := evaluator.GetTimeValue(ctx, col.DefaultValue, col.Tp, col.Decimal)
if err != nil {
return types.Datum{}, true, errGetDefaultFailed.Gen("Field '%s' get default value fail - %s",
col.Name, errors.Trace(err))
}
return value, true, nil
} else if col.Tp == mysql.TypeEnum {
// For enum type, if no default value and not null is set,
// the default value is the first element of the enum list
if col.DefaultValue == nil && mysql.HasNotNullFlag(col.Flag) {
return types.NewDatum(col.FieldType.Elems[0]), true, nil
}
}
value, err := CastValue(ctx, types.NewDatum(col.DefaultValue), col)
if err != nil {
return types.Datum{}, false, errors.Trace(err)
}
return value, true, nil
}
func (e *ShowExec) fetchShowCreateTable() error {
tb, err := e.getTable()
if err != nil {
return errors.Trace(err)
}
// TODO: let the result more like MySQL.
var buf bytes.Buffer
buf.WriteString(fmt.Sprintf("CREATE TABLE `%s` (\n", tb.Meta().Name.O))
var pkCol *table.Column
for i, col := range tb.Cols() {
buf.WriteString(fmt.Sprintf(" `%s` %s", col.Name.O, col.GetTypeDesc()))
if mysql.HasAutoIncrementFlag(col.Flag) {
buf.WriteString(" NOT NULL AUTO_INCREMENT")
} else {
if mysql.HasNotNullFlag(col.Flag) {
buf.WriteString(" NOT NULL")
}
if !mysql.HasNoDefaultValueFlag(col.Flag) {
switch col.DefaultValue {
case nil:
buf.WriteString(" DEFAULT NULL")
case "CURRENT_TIMESTAMP":
buf.WriteString(" DEFAULT CURRENT_TIMESTAMP")
default:
buf.WriteString(fmt.Sprintf(" DEFAULT '%v'", col.DefaultValue))
}
}
if mysql.HasOnUpdateNowFlag(col.Flag) {
buf.WriteString(" ON UPDATE CURRENT_TIMESTAMP")
}
}
if len(col.Comment) > 0 {
buf.WriteString(fmt.Sprintf(" COMMENT '%s'", col.Comment))
}
if i != len(tb.Cols())-1 {
buf.WriteString(",\n")
}
if tb.Meta().PKIsHandle && mysql.HasPriKeyFlag(col.Flag) {
pkCol = col
}
}
if pkCol != nil {
// If PKIsHanle, pk info is not in tb.Indices(). We should handle it here.
buf.WriteString(",\n")
buf.WriteString(fmt.Sprintf(" PRIMARY KEY (`%s`)", pkCol.Name.O))
}
if len(tb.Indices()) > 0 || len(tb.Meta().ForeignKeys) > 0 {
buf.WriteString(",\n")
}
for i, idx := range tb.Indices() {
idxInfo := idx.Meta()
if idxInfo.Primary {
buf.WriteString(" PRIMARY KEY ")
} else if idxInfo.Unique {
buf.WriteString(fmt.Sprintf(" UNIQUE KEY `%s` ", idxInfo.Name.O))
} else {
buf.WriteString(fmt.Sprintf(" KEY `%s` ", idxInfo.Name.O))
}
cols := make([]string, 0, len(idxInfo.Columns))
for _, c := range idxInfo.Columns {
cols = append(cols, c.Name.O)
}
buf.WriteString(fmt.Sprintf("(`%s`)", strings.Join(cols, "`,`")))
if i != len(tb.Indices())-1 {
buf.WriteString(",\n")
}
}
if len(tb.Indices()) > 0 && len(tb.Meta().ForeignKeys) > 0 {
buf.WriteString(",\n")
}
for _, fk := range tb.Meta().ForeignKeys {
if fk.State != model.StatePublic {
continue
}
cols := make([]string, 0, len(fk.Cols))
for _, c := range fk.Cols {
cols = append(cols, c.O)
}
refCols := make([]string, 0, len(fk.RefCols))
for _, c := range fk.Cols {
refCols = append(refCols, c.O)
}
buf.WriteString(fmt.Sprintf(" CONSTRAINT `%s` FOREIGN KEY (`%s`)", fk.Name.O, strings.Join(cols, "`,`")))
buf.WriteString(fmt.Sprintf(" REFERENCES `%s` (`%s`)", fk.RefTable.O, strings.Join(refCols, "`,`")))
if ast.ReferOptionType(fk.OnDelete) != ast.ReferOptionNoOption {
buf.WriteString(fmt.Sprintf(" ON DELETE %s", ast.ReferOptionType(fk.OnDelete)))
}
if ast.ReferOptionType(fk.OnUpdate) != ast.ReferOptionNoOption {
buf.WriteString(fmt.Sprintf(" ON UPDATE %s", ast.ReferOptionType(fk.OnUpdate)))
}
}
buf.WriteString("\n")
buf.WriteString(") ENGINE=InnoDB")
if s := tb.Meta().Charset; len(s) > 0 {
buf.WriteString(fmt.Sprintf(" DEFAULT CHARSET=%s", s))
}
if tb.Meta().AutoIncID > 0 {
buf.WriteString(fmt.Sprintf(" AUTO_INCREMENT=%d", tb.Meta().AutoIncID))
}
if len(tb.Meta().Comment) > 0 {
buf.WriteString(fmt.Sprintf(" COMMENT='%s'", tb.Meta().Comment))
}
data := types.MakeDatums(tb.Meta().Name.O, buf.String())
e.rows = append(e.rows, &Row{Data: data})
return nil
}