mysql存储--游标

游标的使用
要声明，
1.接收游标数据的变量
2.遍历数据结束标志
3.游标数据来源--游标
4.将结束标志绑定到游标
然后才是打开游标
根据标志来操作游标
关游标

CREATE PROCEDURE DEL_SUB1()  
     READS SQL DATA  
BEGIN  
     DECLARE sub_id INT;  
     DECLARE done INT DEFAULT 0;  
     DECLARE cur1 CURSOR FOR select subscribe_id from sy_subscribe where  length(source_keyword)=CHARACTER_LENGTH(source_keyword)  and length(source_keyword)=32;  
     DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;  
  
     OPEN cur1;  
     emp_loop: LOOP  
         FETCH cur1 INTO sub_id;
 select sub_id;  -- 输出到控制台
					if done=0 then 
							update sy_subscribe t , sy_subscribe t1 set  t.source_keyword= t1.source_id , t.source_id = t1.source_keyword ,t.unique_id = CONCAT(t1.source_id,'_',t1.source_keyword)
									where t.subscribe_type = 1 and t.subscribe_id = t1.subscribe_id and t.subscribe_id = sub_id;
					end if;
         IF done=1 THEN  
             LEAVE emp_loop;  
         END IF;  
		
     END LOOP emp_loop;  
     CLOSE cur1;  
END