多选题Which three statements about subqueries are true? （）AAsinglerowsubquerycanretrieveonlyonecolumnandonerow.BAsinglerowsubquerycanretrieveonlyonerowbutmanycolumns.CAmultiplerowsubquerycanretrievemultiplerowsandmultiplecolumns.DAmultiplerowsubquerycanbecom
题目
多选题
Which three statements about subqueries are true? （）
A
Asinglerowsubquerycanretrieveonlyonecolumnandonerow.
B
Asinglerowsubquerycanretrieveonlyonerowbutmanycolumns.
C
Amultiplerowsubquerycanretrievemultiplerowsandmultiplecolumns.
D
Amultiplerowsubquerycanbecomparedusingthe；>；；operator.
E
AsinglerowsubquerycanusetheINoperator.
F
Amultiplerowsubquerycanusethe；=；operator.