// CheckAndUpdateSelectList checks order by fields validity and set hidden fields to selectList.
func (r *OrderByRset) CheckAndUpdateSelectList(selectList *plans.SelectList, tableFields []*field.ResultField) error {
for i, v := range r.By {
if expressions.ContainAggregateFunc(v.Expr) {
expr, err := selectList.UpdateAggFields(v.Expr, tableFields)
if err != nil {
return errors.Errorf("%s in 'order clause'", err.Error())
}
r.By[i].Expr = expr
} else {
names := expressions.MentionedColumns(v.Expr)
for _, name := range names {
// try to find in select list
// TODO: mysql has confused result for this, see #555.
// now we use select list then order by, later we should make it easier.
if field.ContainFieldName(name, selectList.ResultFields, field.CheckFieldFlag) {
// check ambiguous fields, like `select c1 as c2, c2 from t order by c2`.
if err := field.CheckAmbiguousField(name, selectList.ResultFields, field.DefaultFieldFlag); err != nil {
return errors.Errorf("Column '%s' in order statement is ambiguous", name)
}
continue
}
if !selectList.CloneHiddenField(name, tableFields) {
return errors.Errorf("Unknown column '%s' in 'order clause'", name)
}
}
}
}
return nil
}
// Plan gets GroupByDefaultPlan.
func (r *GroupByRset) Plan(ctx context.Context) (plan.Plan, error) {
fields := r.SelectList.Fields
resultfields := r.SelectList.ResultFields
srcFields := r.Src.GetFields()
r.SelectList.AggFields = GetAggFields(fields)
aggFields := r.SelectList.AggFields
for i, e := range r.By {
if v, ok := e.(expressions.Value); ok {
var position int
switch u := v.Val.(type) {
case int64:
position = int(u)
case uint64:
position = int(u)
default:
continue
}
if position < 1 || position > len(fields) {
return nil, errors.Errorf("Unknown column '%d' in 'group statement'", position)
}
index := position - 1
if _, ok := aggFields[index]; ok {
return nil, errors.Errorf("Can't group on '%s'", fields[index].Name)
}
// use Position expression for the associated field.
r.By[i] = &expressions.Position{N: position}
} else {
names := expressions.MentionedColumns(e)
for _, name := range names {
if field.ContainFieldName(name, srcFields, field.DefaultFieldFlag) {
// check whether column is qualified, like `select t.c1 c1, t.c2 from t group by t.c1, t.c2`
// no need to check ambiguous field.
if expressions.IsQualified(name) {
continue
}
// check ambiguous fields, like `select c1 as c2, c2 from t group by c2`.
if err := field.CheckAmbiguousField(name, resultfields, field.DefaultFieldFlag); err == nil {
continue
}
}
// check reference to group function name
indices := field.GetFieldIndex(name, fields[0:r.SelectList.HiddenFieldOffset], field.CheckFieldFlag)
if len(indices) > 1 {
// check ambiguous fields, like `select c1 as a, c2 as a from t group by a`,
// notice that `select c2 as c2, c2 as c2 from t group by c2;` is valid.
if r.HasAmbiguousField(indices, fields[0:r.SelectList.HiddenFieldOffset]) {
return nil, errors.Errorf("Column '%s' in group statement is ambiguous", name)
}
} else if len(indices) == 1 {
// check reference to aggregate function, like `select c1, count(c1) as b from t group by b + 1`.
index := indices[0]
if _, ok := aggFields[index]; ok {
return nil, errors.Errorf("Reference '%s' not supported (reference to group function)", name)
}
}
}
// group by should be an expression, a qualified field name or a select field position,
// but can not contain any aggregate function.
if e := r.By[i]; expressions.ContainAggregateFunc(e) {
return nil, errors.Errorf("group by cannot contain aggregate function %s", e.String())
}
}
}
return &plans.GroupByDefaultPlan{By: r.By, Src: r.Src, SelectList: r.SelectList}, nil
}
func (*testResultFieldSuite) TestMain(c *C) {
col := column.Col{
ColumnInfo: model.ColumnInfo{
FieldType: *types.NewFieldType(mysql.TypeLong),
Name: model.NewCIStr("c1"),
},
}
col.Flag |= mysql.UnsignedFlag
r := &field.ResultField{
Col: col,
Name: "c1",
OrgTableName: "t1",
}
c.Assert(r.String(), Equals, "c1")
r.TableName = "a"
c.Assert(r.String(), Equals, "a.c1")
r.DBName = "test"
c.Assert(r.String(), Equals, "test.a.c1")
cr := r.Clone()
c.Assert(r.String(), Equals, cr.String())
col1 := column.Col{
ColumnInfo: model.ColumnInfo{
FieldType: *types.NewFieldType(mysql.TypeLong),
Name: model.NewCIStr("c2"),
},
}
col1.Flag |= mysql.UnsignedFlag
r1 := &field.ResultField{
Col: col1,
Name: "c2",
TableName: "a",
OrgTableName: "t1",
DBName: "test",
}
rs := []*field.ResultField{r, r1}
ns := field.RFQNames(rs)
c.Assert(ns, HasLen, 2)
c.Assert(ns[0], Equals, "\"c1\"")
c.Assert(ns[1], Equals, "\"c2\"")
col2 := column.Col{
ColumnInfo: model.ColumnInfo{
FieldType: *types.NewFieldType(mysql.TypeVarchar),
Name: model.NewCIStr("c3"),
},
}
col2.Flag |= mysql.UnsignedFlag
col3 := column.Col{
ColumnInfo: model.ColumnInfo{
FieldType: *types.NewFieldType(mysql.TypeBlob),
Name: model.NewCIStr("c4"),
},
}
col3.Flag |= mysql.UnsignedFlag
cols := []*column.Col{&col, &col1, &col2, &col3}
rs = field.ColsToResultFields(cols, "t")
c.Assert(rs, HasLen, 4)
c.Assert(rs[2].Tp, Equals, mysql.TypeVarString)
c.Assert(rs[3].Tp, Equals, mysql.TypeBlob)
// For CheckAmbiguousField
err := field.CheckAmbiguousField("c1", rs, field.OrgFieldNameFlag)
c.Assert(err, IsNil)
col4 := column.Col{
ColumnInfo: model.ColumnInfo{
FieldType: *types.NewFieldType(mysql.TypeVarchar),
Name: model.NewCIStr("c2"),
},
}
r2 := &field.ResultField{
Col: col4,
Name: "c22",
TableName: "b",
OrgTableName: "t2",
DBName: "test",
}
rs = []*field.ResultField{r, r1, r2}
// r1 and r2 are ambiguous: same column name but different table names
err = field.CheckAmbiguousField("c2", rs, field.OrgFieldNameFlag)
c.Assert(err, NotNil)
// r1 and r2 with different alias name
err = field.CheckAmbiguousField("c2", rs, field.FieldNameFlag)
c.Assert(err, IsNil)
// For CloneFieldByName
_, err = field.CloneFieldByName("cx", rs, field.OrgFieldNameFlag)
c.Assert(err, NotNil)
_, err = field.CloneFieldByName("c2", rs, field.OrgFieldNameFlag)
c.Assert(err, IsNil)
// For check all fields name
names := []string{"cx"}
err = field.CheckAllFieldNames(names, rs, field.OrgFieldNameFlag)
c.Assert(err, NotNil)
names = []string{"c1"}
err = field.CheckAllFieldNames(names, rs, field.OrgFieldNameFlag)
c.Assert(err, IsNil)
// For ContainAllFieldNames
names = []string{"cx", "c2"}
b := field.ContainAllFieldNames(names, rs, field.OrgFieldNameFlag)
c.Assert(b, IsFalse)
names = []string{"c2", "c1"}
b = field.ContainAllFieldNames(names, rs, field.OrgFieldNameFlag)
c.Assert(b, IsTrue)
// For GetFieldIndex
f1 := &field.Field{
Expr: &expression.Ident{CIStr: model.NewCIStr("c1")},
AsName: "a",
}
f2 := &field.Field{
Expr: &expression.Ident{CIStr: model.NewCIStr("c2")},
AsName: "a",
}
fs := []*field.Field{f1, f2}
idxs := field.GetFieldIndex("c1", fs, field.OrgFieldNameFlag)
c.Assert(idxs, HasLen, 1)
idxs = field.GetFieldIndex("a", fs, field.FieldNameFlag)
c.Assert(idxs, HasLen, 2)
}