func (sq *subquery) EvalRows(ctx context.Context, rowCount int) ([]types.Datum, error) {
b := newExecutorBuilder(ctx, sq.is)
plan.Refine(sq.plan)
e := b.build(sq.plan)
if b.err != nil {
return nil, errors.Trace(b.err)
}
defer e.Close()
if len(e.Fields()) == 0 {
// No result fields means no Recordset.
for {
row, err := e.Next()
if err != nil {
return nil, errors.Trace(err)
}
if row == nil {
return nil, nil
}
}
}
var (
err error
row *Row
rows []types.Datum
)
for rowCount != 0 {
row, err = e.Next()
if err != nil {
return rows, errors.Trace(err)
}
if row == nil {
break
}
if len(row.Data) == 1 {
rows = append(rows, row.Data[0])
} else {
var d types.Datum
d.SetRow(row.Data)
rows = append(rows, d)
}
if rowCount > 0 {
rowCount--
}
}
return rows, nil
}