解决问题no解决代码问题的博客一条赋值变量引发的巨坑,自己备注一下,浪费了不少时间这边关键字,我都用了大写,方便观看CREATE TRIGGER num_in AFTER INSERT ON user_tFOR EACH ...//赋值SET num = (SELECT COUNT(id) FROM user_t);UPDATE co...
lzxomg的博客mysql 表table_a B字段值赋值给A字段 update 语句 -- 同一个表 UPDATE table_a SET A=(SELECT B FROM (SELECT * FROM table_a) b WHERE b.id = table_a.id) -- 两个表 UPDATE table_a SET A = (SELECT B FROM ...
DokcelyNg的博客select case field when ‘’ then ‘指定一个值’ when '未知’then ‘指定一个值’ else field end ...select case when field =’’ then ‘指定一个值’ when field is null then ‘指定一个值’ els...