Question

Only one expression can be specified in the select list when the subquery is not introduced with exists. True or False

Answer 1

True

Step-by-step explanation:

Subquery can not return more than one (multiple) column, because the output can be compared with one column.

For example;

• SELECT * From Table1 WHERE Column1 IN (SELECT ColumnA FROM Table2)

is a correct statement where

• SELECT * From Table1 WHERE Column1 IN (SELECT ColumnA,ColumnB FROM Table2)

gives an error.