// Plan get SrcPlan/OrderByDefaultPlan.
// If src is NullPlan or order by fields are empty, then gets SrcPlan.
// Default gets OrderByDefaultPlan.
func (r *OrderByRset) Plan(ctx context.Context) (plan.Plan, error) {
if _, ok := r.Src.(*plans.NullPlan); ok {
return r.Src, nil
}
var (
by []expression.Expression
ascs []bool
)
fields := r.Src.GetFields()
for i := range r.By {
e := r.By[i].Expr
if v, ok := e.(expressions.Value); ok {
var (
position int
isPosition = true
)
switch u := v.Val.(type) {
case int64:
position = int(u)
case uint64:
position = int(u)
default:
isPosition = false
// only const value
}
if isPosition {
if position < 1 || position > len(fields) {
return nil, errors.Errorf("Unknown column '%d' in 'order clause'", position)
}
// use Position expression for the associated field.
r.By[i].Expr = &expressions.Position{N: position}
}
} else {
colNames := expressions.MentionedColumns(e)
if err := field.CheckAllFieldNames(colNames, fields, field.CheckFieldFlag); err != nil {
return nil, errors.Trace(err)
}
}
by = append(by, r.By[i].Expr)
ascs = append(ascs, r.By[i].Asc)
}
// if no order by key, use src plan instead.
if len(by) == 0 {
return r.Src, nil
}
return &plans.OrderByDefaultPlan{By: by, Ascs: ascs, Src: r.Src,
SelectList: r.SelectList}, nil
}
// ResolveSelectList gets fields and result fields from selectFields and srcFields,
// including field validity check and wildcard field processing.
func ResolveSelectList(selectFields []*field.Field, srcFields []*field.ResultField) (*SelectList, error) {
selectList := &SelectList{
Fields: make([]*field.Field, 0, len(selectFields)),
ResultFields: make([]*field.ResultField, 0, len(selectFields)),
AggFields: make(map[int]struct{}),
}
wildcardNum := 0
for _, v := range selectFields {
if err := expressions.CheckOneColumn(v.Expr); err != nil {
return nil, errors.Trace(err)
}
// Check metioned field.
names := expressions.MentionedColumns(v.Expr)
if len(names) == 0 {
selectList.AddField(v, nil)
continue
}
// Check wildcard field.
name := names[0]
table, ok, err := field.CheckWildcardField(name)
if err != nil {
return nil, err
}
if ok {
// Check unqualified wildcard field number,
// like `select *, * from t`.
if table == "" {
wildcardNum++
if wildcardNum > 1 {
return nil, errors.Errorf("wildcard field exist more than once")
}
}
selectList.updateFields(table, srcFields)
continue
}
var result *field.ResultField
if err = field.CheckAllFieldNames(names, srcFields, field.DefaultFieldFlag); err != nil {
return nil, errors.Trace(err)
}
if _, ok := v.Expr.(*expressions.Ident); ok {
// Field is ident.
if result, err = field.CloneFieldByName(name, srcFields, field.DefaultFieldFlag); err != nil {
return nil, errors.Trace(err)
}
// Maybe alias name or only column name.
if !expressions.IsQualified(v.Name) {
result.Name = v.Name
}
} else {
// The field is not an ident, maybe binary expression,
// like `select c1 + c2`, or `select c1 + 10`, etc.
result = &field.ResultField{Name: v.Name}
}
selectList.AddField(v, result)
}
selectList.HiddenFieldOffset = len(selectList.Fields)
selectList.resolveAggFields()
if selectList.HiddenFieldOffset == 0 {
return nil, errors.Errorf("invalid empty select fields")
}
return 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)
}
// ResolveSelectList gets fields and result fields from selectFields and srcFields,
// including field validity check and wildcard field processing.
func ResolveSelectList(selectFields []*field.Field, srcFields []*field.ResultField) (*SelectList, error) {
selectList := &SelectList{
Fields: make([]*field.Field, 0, len(selectFields)),
ResultFields: make([]*field.ResultField, 0, len(selectFields)),
AggFields: make(map[int]struct{}),
FromFields: srcFields,
}
wildcardNum := 0
for _, v := range selectFields {
// Check metioned field.
names := expression.MentionedColumns(v.Expr)
if len(names) == 0 {
selectList.AddField(v, nil)
continue
}
// Check wildcard field.
name := names[0]
table, ok, err := field.CheckWildcardField(name)
if err != nil {
return nil, err
}
if ok {
// Check unqualified wildcard field number,
// like `select *, * from t`.
if table == "" {
wildcardNum++
if wildcardNum > 1 {
return nil, errors.Errorf("wildcard field exist more than once")
}
}
selectList.updateFields(table, srcFields)
continue
}
var result *field.ResultField
if err = field.CheckAllFieldNames(names, srcFields, field.DefaultFieldFlag); err != nil {
return nil, errors.Trace(err)
}
if _, ok := v.Expr.(*expression.Ident); ok {
// Field is ident.
if result, err = field.CloneFieldByName(name, srcFields, field.DefaultFieldFlag); err != nil {
return nil, errors.Trace(err)
}
// Use alias name
if len(v.AsName) > 0 {
result.Name = v.AsName
} else {
// use field identifier name directly, but not contain qualified name.
// e.g, select t.c will only return c as the column name.
s := v.Expr.String()
n := strings.LastIndexByte(s, '.')
if n == -1 {
result.Name = s
} else {
result.Name = s[n+1:]
}
}
}
selectList.AddField(v, result)
}
selectList.HiddenFieldOffset = len(selectList.Fields)
selectList.resolveAggFields()
if selectList.HiddenFieldOffset == 0 {
return nil, errors.Errorf("invalid empty select fields")
}
return selectList, nil
}