func (v *havingVisitor) VisitCall(c *expression.Call) (expression.Expression, error) {
isAggregate := expression.IsAggregateFunc(c.F)
if v.inAggregate && isAggregate {
// aggregate function can't contain aggregate function
return nil, errors.Errorf("Invalid use of group function")
}
if isAggregate {
// set true to let outer know we are in aggregate function.
v.inAggregate = true
}
var err error
for i, e := range c.Args {
c.Args[i], err = e.Accept(v)
if err != nil {
return nil, errors.Trace(err)
}
}
if isAggregate {
v.inAggregate = false
}
return c, nil
}
func (v *groupByVisitor) VisitCall(c *expression.Call) (expression.Expression, error) {
ok := expression.IsAggregateFunc(c.F)
if ok {
return nil, errors.Errorf("group by cannot contain aggregate function %s", c)
}
var err error
for i, e := range c.Args {
c.Args[i], err = e.Accept(v)
if err != nil {
return nil, errors.Trace(err)
}
}
return c, nil
}