Ecovacs deebot 665 vs n79wPostgreSQL evaluates the Boolean expressions sequentially from top to bottom until one expression is true. Then the evaluation stops and the corresponding statement are executed. The control is passed to the next statement after the END CASE. In case no true result found, the statements in the ELSE clause are executed. The ELSE clause is optional.Control tactics definitionCode language: Shell Session (shell) In this example, the too_many_rows exception occurs because the select into statement returns more than one row while it is supposed to return one row.. 3) Handling multiple exceptions. The following example illustrates how to catch multiple exceptions: