PL/SQL学习笔记之条件控制语句

IF (condition) THEN
commands;
END IF;

IF (condition) THEN
S1;
ELSE
S2;
END IF;

IF(boolean_expression 1)THEN
S1;
ELSIF( boolean_expression 2) THEN
S2;
ELSIF( boolean_expression 3) THEN
S3;
ELSE
S4;
END IF;

CASE selector
WHEN 'value1' THEN S1;
WHEN 'value2' THEN S2;
WHEN 'value3' THEN S3;
...
ELSE Sn;  -- default case
END CASE;

CASE
WHEN selector = 'value1' THEN S1;
WHEN selector = 'value2' THEN S2;
WHEN selector = 'value3' THEN S3;
...
ELSE Sn;  -- default case
END CASE;