『ORACLE』 PLSQL—基本循环（11g）

循环原则：

如果循环内部必须执行一次，则使用基本循环

如果知道循环次数，则使用FOR循环

如果必须在每次循环开始时判断条件，则使用WHILE循环

1、基本循环

SQL> declare
2 i number := 0;
3 begin
4 loop
5 dbms_output.put_line(i);
6 i := i+1;
7 exit when i = 10;
8 end loop;
9 end;
10 /
0
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9

PL/SQL procedure successfully completed.

 

SQL> declare
2 i number := 0;
3 begin
4 loop
5 i := i+1;
6 dbms_output.put_line(i);
7 exit when i = 10;
8 end loop;
9 end;
10 /
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10

PL/SQL procedure successfully completed.

2、FOR循环

 

SQL> declare
2 i number := 0 ;
3 begin
4 for i in 0 .. 10 loop
5 dbms_output.put_line(i);
6 end loop;
7 end;
8 /
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10

 

PL/SQL procedure successfully completed.

3、WHILE循环

SQL> declare
2 i number:=0;
3 begin
4 while i<=10 loop
5 dbms_output.put_line(i);
6 i:=i+1;
7 end loop;
8 end;
9 /
0
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10

PL/SQL procedure successfully completed.