Mysql5.7下的三種循環

方法一:while .....do.....end while
create procedure pwhile()
begin
declare i int;
set i = 0;
while i <10 do
insert into table_name values (i);
set i = i+1;
end while;
end;

call pwhile();

方法二:repeat ....until... end repeat
create procedure prepeat()
begin
declare i int ;
set i =0;
repeat
insert into table_name values(i);
set i +=1;
until i <20;
end repeat;
end;

call prepeat();

方法三:loop ....end loop
create procedure ploop()
begin
declare i int;
set i = 0;
loop_lable:loop
insert into table_name values (i);
set i = i+1;
if i >=20 then
leave loop_table;
end if ;
end loop;
end;
call ploop();

利用iterate 迭代循環,當然,iterate既可用於loop循環,也可用於while,repeate 這幾種循環中,下面,以將iterate 用於loop循環爲例:

create procedure piter()
begin
declare i int;
set i = 35;
loop_label:loop
if i = 43 then
set i = i+1;
iterate loop_label;
end if;
insert into t4 values(i);
set i = i+1;
if i>50 then
leave loop_label
end if;
end loop;
end;

call piter();


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