The following statement adds the HAVING clause to select the only customers who have been spending more than 200: SELECT The following query uses the GROUP BY clause with the SUM() function to find the total amount of each customer: SELECTĬustomer_id Code language: SQL (Structured Query Language) ( sql ) 1) Using PostgreSQL HAVING clause with SUM function example Let’s take a look at the paymenttable in the sample database. In other words, the WHERE clause is applied to rows while the HAVING clause is applied to groups of rows. However, the HAVING clause allows you to filter groups of rows according to a specified condition. The WHERE clause allows you to filter rows based on a specified condition. Because at the time of evaluating the HAVING clause, the column aliases specified in the SELECT clause are not available. Since the HAVING clause is evaluated before the SELECT clause, you cannot use column aliases in the HAVING clause. PostgreSQL evaluates the HAVING clause after the FROM, WHERE, GROUP BY, and before the SELECT, DISTINCT, ORDER BY and LIMIT clauses. It’s possible to add other clauses of the SELECT statement such as JOIN, LIMIT, FETCH etc. The HAVING clause specifies a condition to filter the groups. In this syntax, the group by clause returns rows grouped by the column1. The following statement illustrates the basic syntax of the HAVINGclause: SELECTĬondition Code language: SQL (Structured Query Language) ( sql ) The HAVING clause is often used with the GROUP BY clause to filter groups or aggregates based on a specified condition. The HAVING clause specifies a search condition for a group or an aggregate. Summary: in this tutorial, you will learn how to use the PostgreSQL HAVING clause to specify a search condition for a group or an aggregate.
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