mysql 存储过程 字段去重
BEGIN
DECLARE bl_id int;
DECLARE from_ids varchar(100);
DECLARE bl_from_id varchar(100);#中间变量
DECLARE i int;
DECLARE Done INT DEFAULT 0;
DECLARE IMP_TABLE_CUR CURSOR FOR
(select id,from_id from weixin_fromid ORDER BY from_id); #from_id要去重的字段
DECLARE IMP_TABLE_VALID_CUR CURSOR FOR
select id,from_id from weixin_fromid ORDER BY from_id;
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1;
set bl_from_id='a';#选一个from_id达不到的值
set i=0;
open IMP_TABLE_CUR;
FETCH next from IMP_TABLE_CUR INTO bl_id,from_ids; -- 获取游标里的值
repeat
IF NOT Done THEN
if bl_from_id=from_ids THEN
DELETE from weixin_fromid where id=bl_id;
set i=i+1;
ELSE
set bl_from_id=from_ids;
end if;
end if;
FETCH next from IMP_TABLE_CUR INTO bl_id,from_ids;
until done end repeat;
select i;
END
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