what is this operator..i'ven't seen it before
517790Jun 12 2006 — edited Jun 12 2006You define a multiple-row subquery in the WHERE clause of an SQL query with a comparison operator&qu
ot;=" What happens when the main query is executed?
A. the main query executes with the first value returned by the subquery
B. the main query executes with the last value returned by the subquery
C. the main query executes with all the values returned by the subquery
D. the main query fails because the multiple-row subquery cannot be used with the comparison op
erator.
E. You cannot define multiple-row subquery in the WHERE clause of a SQL query
Explanation: The main query fails because the multiple-row sub-query cannot be used with the comparison operator. Only single-row query can use comparison operators, like =, <, >, <=, >, and & lt;>. Incorrect Answers A: The main query fails because the multiple-row sub-query cannot be used with the comparison operator. B: The main query fails because the multiple-row sub-query cannot be used with the comparison operator. C: The main query fails because the multiple-row sub-query cannot be used with the comparison operator. E: You can define a multiple-row sub-query in the WHERE clause of a SQL query, but error will be generated by different reason. OCP Introduction to Oracle 9i: SQL Exam Guide, Jason Couchman, p. 150-165 Chapter 4: Subqueries