func (nr *nameResolver) resolveColumnInResultFields(cn *ast.ColumnNameExpr, rfs []*ast.ResultField) bool {
if cn.Name.Table.L != "" {
// Skip result fields, resolve the column in table source.
return false
}
var matched *ast.ResultField
for _, rf := range rfs {
matchAsName := cn.Name.Name.L == rf.ColumnAsName.L
matchColumnName := rf.ColumnAsName.L == "" && cn.Name.Name.L == rf.Column.Name.L
if matchAsName || matchColumnName {
if rf.Column.Name.L == "" {
// This is not a real table column, resolve it directly.
cn.Refer = rf
return true
}
if matched == nil {
matched = rf
} else {
sameColumn := matched.Table.Name.L == rf.Table.Name.L && matched.Column.Name.L == rf.Column.Name.L
if !sameColumn {
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
return true
}
}
}
}
if matched != nil {
// Bind column.
cn.Refer = matched
return true
}
return false
}
func (nr *nameResolver) resolveColumnInResultFields(ctx *resolverContext, cn *ast.ColumnNameExpr, rfs []*ast.ResultField) bool {
var matched *ast.ResultField
for _, rf := range rfs {
if cn.Name.Table.L != "" {
// Check table name
if rf.TableAsName.L != "" {
if cn.Name.Table.L != rf.TableAsName.L {
continue
}
} else if cn.Name.Table.L != rf.Table.Name.L {
continue
}
}
matchAsName := cn.Name.Name.L == rf.ColumnAsName.L
var matchColumnName bool
if ctx.inHaving {
matchColumnName = cn.Name.Name.L == rf.Column.Name.L
} else {
matchColumnName = rf.ColumnAsName.L == "" && cn.Name.Name.L == rf.Column.Name.L
}
if matchAsName || matchColumnName {
if rf.Column.Name.L == "" {
// This is not a real table column, resolve it directly.
cn.Refer = rf
rf.Referenced = true
return true
}
if matched == nil {
matched = rf
} else {
sameColumn := matched.TableName == rf.TableName && matched.Column.Name.L == rf.Column.Name.L
if !sameColumn {
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
return true
}
}
}
}
if matched != nil {
// If in GroupBy, we clone the ResultField
if ctx.inGroupBy || ctx.inHaving || ctx.inOrderBy {
nf := *matched
expr := matched.Expr
if cexpr, ok := expr.(*ast.ColumnNameExpr); ok {
expr = cexpr.Refer.Expr
}
nf.Expr = expr
matched = &nf
}
// Bind column.
cn.Refer = matched
matched.Referenced = true
return true
}
return false
}
func (nr *nameResolver) resolveColumnInTableSources(cn *ast.ColumnNameExpr, tableSources []*ast.TableSource) (done bool) {
var matchedResultField *ast.ResultField
tableNameL := cn.Name.Table.L
columnNameL := cn.Name.Name.L
if tableNameL != "" {
var matchedTable ast.ResultSetNode
for _, ts := range tableSources {
if tableNameL == ts.AsName.L {
// different table name.
matchedTable = ts
break
} else if ts.AsName.L != "" {
// Table as name shadows table real name.
continue
}
if tn, ok := ts.Source.(*ast.TableName); ok {
if cn.Name.Schema.L != "" && cn.Name.Schema.L != tn.Schema.L {
continue
}
if tableNameL == tn.Name.L {
matchedTable = ts
}
}
}
if matchedTable != nil {
resultFields := matchedTable.GetResultFields()
for _, rf := range resultFields {
if rf.ColumnAsName.L == columnNameL || rf.Column.Name.L == columnNameL {
// resolve column.
matchedResultField = rf
break
}
}
}
} else {
for _, ts := range tableSources {
rfs := ts.GetResultFields()
for _, rf := range rfs {
matchAsName := rf.ColumnAsName.L != "" && rf.ColumnAsName.L == columnNameL
matchColumnName := rf.ColumnAsName.L == "" && rf.Column.Name.L == columnNameL
if matchAsName || matchColumnName {
if matchedResultField != nil {
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
return true
}
matchedResultField = rf
}
}
}
}
if matchedResultField != nil {
// Bind column.
cn.Refer = matchedResultField
matchedResultField.Referenced = true
return true
}
return false
}
func (nr *nameResolver) resolveColumnInResultFields(ctx *resolverContext, cn *ast.ColumnNameExpr, rfs []*ast.ResultField) bool {
var matched *ast.ResultField
for _, rf := range rfs {
if cn.Name.Table.L != "" {
// Check table name
if rf.TableAsName.L != "" {
if cn.Name.Table.L != rf.TableAsName.L {
continue
}
} else if cn.Name.Table.L != rf.Table.Name.L {
continue
}
}
matchAsName := cn.Name.Name.L == rf.ColumnAsName.L
var matchColumnName bool
if ctx.inHaving {
matchColumnName = cn.Name.Name.L == rf.Column.Name.L
} else {
matchColumnName = rf.ColumnAsName.L == "" && cn.Name.Name.L == rf.Column.Name.L
}
if matchAsName || matchColumnName {
if rf.Column.Name.L == "" {
// This is not a real table column, resolve it directly.
cn.Refer = rf
return true
}
if matched == nil {
matched = rf
} else {
sameColumn := matched.TableName == rf.TableName && matched.Column.Name.L == rf.Column.Name.L
if !sameColumn {
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
return true
}
}
}
}
if matched != nil {
// Bind column.
cn.Refer = matched
return true
}
return false
}
func (e *Evaluator) columnName(v *ast.ColumnNameExpr) bool {
v.SetDatum(*v.Refer.Expr.GetDatum())
return true
}
// resolveColumnNameInContext looks up and sets ResultField for a column with the ctx.
func (nr *nameResolver) resolveColumnNameInContext(ctx *resolverContext, cn *ast.ColumnNameExpr) bool {
if ctx.inTableRefs {
// In TableRefsClause, column reference only in join on condition which is handled before.
return false
}
if ctx.inFieldList {
// only resolve column using tables.
return nr.resolveColumnInTableSources(cn, ctx.tables)
}
if ctx.inGroupBy {
// From tables first, then field list.
// If ctx.InByItemExpression is true, the item is not an identifier.
// Otherwise it is an identifier.
if ctx.inByItemExpression {
// From table first, then field list.
if nr.resolveColumnInTableSources(cn, ctx.tables) {
return true
}
found := nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
if nr.Err == nil && found {
// Check if resolved refer is an aggregate function expr.
if _, ok := cn.Refer.Expr.(*ast.AggregateFuncExpr); ok {
nr.Err = ErrIllegalReference.Gen("Reference '%s' not supported (reference to group function)", cn.Name.Name.O)
}
}
return found
}
// Resolve from table first, then from select list.
found := nr.resolveColumnInTableSources(cn, ctx.tables)
if nr.Err != nil {
return found
}
// We should copy the refer here.
// Because if the ByItem is an identifier, we should check if it
// is ambiguous even it is already resolved from table source.
// If the ByItem is not an identifier, we do not need the second check.
r := cn.Refer
if nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList) {
if nr.Err != nil {
return true
}
if r != nil {
// It is not ambiguous and already resolved from table source.
// We should restore its Refer.
cn.Refer = r
}
if _, ok := cn.Refer.Expr.(*ast.AggregateFuncExpr); ok {
nr.Err = ErrIllegalReference.Gen("Reference '%s' not supported (reference to group function)", cn.Name.Name.O)
}
return true
}
return found
}
if ctx.inHaving {
// First group by, then field list.
if nr.resolveColumnInResultFields(ctx, cn, ctx.groupBy) {
return true
}
if ctx.inHavingAgg {
// If cn is in an aggregate function in having clause, check tablesource first.
if nr.resolveColumnInTableSources(cn, ctx.tables) {
return true
}
}
return nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
}
if ctx.inOrderBy {
if nr.resolveColumnInResultFields(ctx, cn, ctx.groupBy) {
return true
}
if ctx.inByItemExpression {
// From table first, then field list.
if nr.resolveColumnInTableSources(cn, ctx.tables) {
return true
}
return nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
}
// Field list first, then from table.
if nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList) {
return true
}
return nr.resolveColumnInTableSources(cn, ctx.tables)
}
// In where clause.
return nr.resolveColumnInTableSources(cn, ctx.tables)
}
// resolveColumnNameInContext looks up and sets ResultField for a column with the ctx.
func (nr *nameResolver) resolveColumnNameInContext(ctx *resolverContext, cn *ast.ColumnNameExpr) bool {
if ctx.inTableRefs {
// In TableRefsClause, column reference only in join on condition which is handled before.
return false
}
if ctx.inFieldList {
// only resolve column using tables.
return nr.resolveColumnInTableSources(cn, ctx.tables)
}
if ctx.inGroupBy {
// From tables first, then field list.
// If ctx.InByItemExpression is true, the item is not an identifier.
// Otherwise it is an identifier.
if ctx.inByItemExpression {
// From table first, then field list.
if nr.resolveColumnInTableSources(cn, ctx.tables) {
return true
}
return nr.resolveColumnInResultFields(cn, ctx.fieldList)
}
// Resolve from table first, then from select list.
found := nr.resolveColumnInTableSources(cn, ctx.tables)
if nr.Err != nil {
return found
}
// We should copy the refer here.
// Because if the ByItem is an identifier, we should check if it
// is ambiguous even it is already resolved from table source.
// If the ByItem is not an identifier, we do not need the second check.
r := cn.Refer
if nr.resolveColumnInResultFields(cn, ctx.fieldList) {
if nr.Err != nil {
return true
}
if r != nil {
// It is not ambiguous and already resolved from table source.
// We should restore its Refer.
cn.Refer = r
}
return true
}
return found
}
if ctx.inHaving {
// First group by, then field list.
if nr.resolveColumnInResultFields(cn, ctx.groupBy) {
return true
}
return nr.resolveColumnInResultFields(cn, ctx.fieldList)
}
if ctx.inOrderBy {
if nr.resolveColumnInResultFields(cn, ctx.groupBy) {
return true
}
if ctx.inByItemExpression {
// From table first, then field list.
if nr.resolveColumnInTableSources(cn, ctx.tables) {
return true
}
return nr.resolveColumnInResultFields(cn, ctx.fieldList)
}
// Field list first, then from table.
if nr.resolveColumnInResultFields(cn, ctx.fieldList) {
return true
}
return nr.resolveColumnInTableSources(cn, ctx.tables)
}
// In where clause.
return nr.resolveColumnInTableSources(cn, ctx.tables)
}