func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
pos.Refer = ctx.fieldList[pos.N-1]
}
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
pos.Refer = ctx.fieldList[pos.N-1]
if nr.currentContext().inGroupBy {
// make sure item is not aggregate function
if ast.HasAggFlag(pos.Refer.Expr) {
nr.Err = errors.New("group by cannot contain aggregate function")
}
}
}
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
matched := ctx.fieldList[pos.N-1]
nf := *matched
expr := matched.Expr
if cexpr, ok := expr.(*ast.ColumnNameExpr); ok {
expr = cexpr.Refer.Expr
}
nf.Expr = expr
pos.Refer = &nf
if nr.currentContext().inGroupBy {
// make sure item is not aggregate function
if ast.HasAggFlag(pos.Refer.Expr) {
nr.Err = errors.New("group by cannot contain aggregate function")
}
}
}
func (e *Evaluator) position(v *ast.PositionExpr) bool {
v.SetDatum(*v.Refer.Expr.GetDatum())
return true
}