Index: plsql.sgml =================================================================== RCS file: /home/projects/pgsql/cvsroot/pgsql/doc/src/sgml/plsql.sgml,v retrieving revision 2.32 diff -w -b -i -B -c -r2.32 plsql.sgml *** plsql.sgml 2001/05/17 21:50:16 2.32 --- plsql.sgml 2001/05/22 12:38:49 *************** *** 880,891 **** Conditional Control: IF statements ! IF statements let you take action ! according to certain conditions. PL/pgSQL has three forms of ! IF: IF-THEN, IF-THEN-ELSE, IF-THEN-ELSE IF. NOTE: All ! PL/pgSQL IF statements need a corresponding END ! IF statement. In ELSE-IF statements you need two: ! one for the first IF and one for the second (ELSE IF). --- 880,890 ---- Conditional Control: IF statements ! IF statements let you execute commands based on ! certain conditions. PL/PgSQL has four forms of IF: IF-THEN, IF-THEN-ELSE, ! IF-THEN-ELSE IF, IF-THEN-ELSIF-THEN-ELSE. NOTE: All PL/PgSQL IF statements need ! a corresponding END IF clause. With ELSE-IF statements, ! you need two: one for the first IF and one for the second (ELSE IF). *************** *** 979,984 **** --- 978,1018 ---- + + + + IF-THEN-ELSIF-ELSE + + + + + IF-THEN-ELSIF-ELSE allows you test multiple conditions + in one statement. Internally it is handled as nested + IF-THEN-ELSE-IF-THEN commands. The optional ELSE + branch is executed when none of the conditions are met. + + + + Here is an example: + + + + IF number = 0 THEN + result := ''zero''; + ELSIF number < 0 THEN + result := ''negative''; + ELSIF number > 0 THEN + result := ''negative''; + ELSE + -- now it seems to be NULL + result := ''NULL''; + END IF; + + + + + +