数据库超级传送门

IF

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--- IF
IF <EXPRESSION1> THEN
    OPERATION1;
END IF;
--- IF ELSE
IF <EXPRESSION1> THEN
    OPERATION1;
ELSE
    OPERATION2;
END IF;
--- IF ELSIF
IF <EXPRESSION1> THEN
    OPERATION1;
ELSIF <EXPRESSION1> THEN
    OPERATION2;
……
ELSE
    OPERATION3;
END IF;

CASE

如果case语句没有用else并且when中没有匹配项，将会返回一个错误。

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SET SERVEROUTPUT ON
DECLARE
i number:=1;
BEGIN
    CASE i
        WHEN 0 THEN
            dbms_output.put_line('i is 0');
        WHEN 1 THEN
            dbms_output.put_line('i is 1');
        ELSE
            dbms_output.put_line('i is more than 1');
    END CASE
END;
/

循环

LOOP无条件循环

exit when 是可选项，不写的话就永远循环下去了

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LOOP
    OPERATION1
    EXIT WHEN <EXPRESSIOIN1>;
END LOOP;

WHILE循环

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WHILE <EXPRESSION1> LOOP
    OPEARATOIN1
END LOOP;

FOR循环

当在IN 后面输入REVERSE后，是在要求范围内降序循环

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SET SERVEROUTPUT ON 
DECLARE
    sum number:=0;
BEGIN
    FOR i IN 1..100 LOOP
        sum:=sum+i;
    END LOOP;
    dbms_output.put_line('sum is '|| sum);
END;
/

GOTO

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SET SERVEROUTPUT ON 
DECLARE
    SUM number:=0;
BEGIN
    IF SUM > 0 THEN
        GOTO position1;
    ELSIF SUM<=0 THEN
        GOTO position2;
    END IF;
<<position1>>
    dbms_output.put_line('Here is position1');
<<position2>>
    dbms_output.put_line('Here is position2');
END;
/