MySQL判断字符串是否是数字
SELECT * FROM **** WHERE trim(字段名) REGEXP '[^0-9]'=1
select count(id),字段from 表名 group by字段 having count(字段)>1;...
mysql> select CONCAT('My', 'S', 'QL');...
SELECT product_brand FROM shop_product WHERE LENGTH(product_brand)>...
是由表格字段ID的数据库类型造成的,smallint最大数值就是65535,修改成int就可以了...
DELETE t1 FROM invest_year t1, invest_year t2 WHERE t1.pro_id = t2.pro_id AND t1.pro_year = t...
truncate table 表名...