mysql存储过程执行动态SQL

不需要使用游标循环来读取，直接select * into @变量就OK了，还可以传递参数来执行。 
MySql通用分页存储过程
 
 过程参数
 4 p_cloumns varchar(500),p_tables varchar(100),p_where varchar(4000),p_order varchar(100),p_pageindex int,p_pagesize int,out p_recordcount int,out p_pagecount int
 5
 6 $$:begin
 7 declare v_sqlcounts varchar(4000);
 8 declare v_sqlselect varchar(4000);
 9 #拼接查询总记录的SQL语句
10 set v_sqlcounts = concat('select count(*) into @recordcount from ',p_tables,p_where);
11 #select v_sqlcounts;leave $$;
12 set @sqlcounts = v_sqlcounts;
13 prepare stmt from @sqlcounts;
14 execute stmt;
15 deallocate prepare stmt;
16 #获取动态SQL语句返回值
17 set p_recordcount = @recordcount;
18 #根据总记录跳数计算出总页数
19 set p_pagecount = ceiling((p_recordcount+0.0)/p_pagesize);
20 if p_pageindex <1 then
21 set p_pageindex = 1;
22 elseif p_pageindex > p_pagecount and p_pagecount <> 0 then
23 set p_pageindex = p_pagecount;
24 end if;
25 #拼接分页查询记录的动态SQL语句
26 set v_sqlselect = concat('select ',p_cloumns,' from ',p_tables,p_where,if(p_order is not null,p_order,''),' limit ',(p_pageindex-1)*p_pagesize,' , ',p_pagesize);
27 #select v_sqlselect;leave $$;
28 set @sqlselect = v_sqlselect;
29 prepare stmtselect from @sqlselect;
30 execute stmtselect;
31 deallocate prepare stmtselect;
32end $$

#拼接查询总记录的SQL语句 set v_sqlcounts = concat('select count(*) into @recordcount from ',v_tables,v_where); set @sqlcounts := v_sqlcounts; #预处理动态SQL prepare stmt from @sqlcounts; #传递动态SQL内参数 set @s1= categoryid; execute stmt using @s1; deallocate prepare stmt; #获取动态SQL语句返回值 set recordcount = @recordcount;

 以上我上再做存储过程分页里用到动态SQL里将查询到的count记录条数通过变量@recordcount放到recordcount里面了。

mysql的IF ELSE和其他数据库的判断有点不一样，简单的判断语句如下。

#根据总记录跳数计算出总页数 set pagecount = ceiling((recordcount+0.0)/pagesize); if pageindex <1 then set pageindex = 1; elseif pageindex > pagecount then set pageindex = pagecount; else select pageindex,pagecount; end if;