该存储过程是根据用户输入的条件和排序方式查询用户的信息，排序条件可以没有
调用方式：call GetUsersDynamic('age<=30','');
/********动态查询用户的信息********/
CREATE PROCEDURE GetUsersDynamic(WhereCondition varchar(500),OrderByExpress varchar(100))
begin
declare stmt varchar(2000);
if LENGTH(OrderbyExpress)>0 then
begin
set @sqlstr=concat('select id,name,password,age,getdate(adddate) as AddDate from users where ',WhereCondition,' order by ',OrderByExpress);
end;
else
begin
set @sqlstr=concat('select id,name,password,age,getdate(adddate) as AddDate from users where ',WhereCondition);
end;
end if;
prepare stmt from @sqlstr;
execute stmt;
end;
getdate()是一个自定义的函数，作用是返回日期的短格式
CREATE DEFINER=`root`@`localhost` FUNCTION `getdate`($date datetime) RETURNS varchar(50) CHARSET latin1
return date_format($date,'%Y-%m-%d');
动态插入数据的存储过程，（注意四个单引号表示一个一引号）：
CREATE DEFINER=`root`@`localhost` PROCEDURE `InsertUser`(in name2 varchar(50),in password2 varchar(32),in age2 int,in adddate2 datetime)
begin
DECLARE stmt varchar(2000);
set @sqlstr=concat('insert into users(name,password,age,adddate) values(');
set @sqlstr=concat(@sqlstr,'''',name2,'''',',','''',password2,'''',',',age2,',','''',adddate2,'''',')');
prepare stmt from @sqlstr;
execute stmt;
end;
（http://www.bmestu.com/studynewstail.asp?Stnew_ID=1321）
另一种带参数的形式：
在mysql存储过程中动态执行sql文
mysql> PREPARE stmt1 FROM 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse';
mysql> SET @a = 3;
mysql> SET @b = 4;
mysql> EXECUTE stmt1 USING @a, @b;
mysql> SET @a = 'select * from table1 ';
mysql> SET @b = 'where column1>10 limit 1';
mysql> SET @a = concat(@a,@b);
mysql> PREPARE stmt1 FROM @a;
mysql> EXECUTE stmt1;
