createprocedure if_exp(in s_id int,in name_or_major int,in name_major varchar(20)) begin if name_or_major=1then update student set name=name_major where id=s_id; endif; if name_or_major=2then update student set major=name_major where id=s_id; endif; end//
执行结果如下:
三、case分支语句
如果是采用case语句,则其语法结构为:
case 【变量】 when 【值1】 then 【语句1】 when 【值2】 then 【语句2】 …… endcase;
case分支存储过程SQL语句示例如下:
createprocedure case_exp(in s_id int,in name_or_major int,in name_major varchar(30)) begin case name_or_major when1then update student set name=name_major where id=s_id; when2then update student set name=name_major where id=s_id; endcase; end//