The Having clause enables you to specify conditions for groups of rows (for example, display only the departments that have salaries totaling more than $200,000). This clause is valid only if you have already defined a Group By clause. It has the following form:

HAVING expr1rel_operatorexpr2

expr1 and expr2 can be field names, constant values, or expressions. These expressions do not have to match a column expression in the Select clause.

rel_operator is the relational operator that links the two expressions. See SQL Expressions for details.

The following example returns only the departments whose sums of salaries are greater than $200,000:

SELECT dept_id, sum(salary) FROM emp

GROUP BY dept_id HAVING sum(salary) > 200000