摘要:
删除重复的记录 mysql> SELECT goods_id,goods_name FROM tdb_goods GROUP BY goods_name HAVING count(goods_name) >= 2;+ + +| goods_id | goods_name |+ + +| 18 | H 阅读全文
摘要:
mysql> CREATE TABLE tdb_goods_types( -> type_id SMALLINT UNSIGNED PRIMARY KEY AUTO_INCREMENT, -> type_name VARCHAR(20) NOT NULL, -> parent_id SMALLINT 阅读全文
摘要:
mysql> SELECT goods_id,goods_name,cate_name,brand_name,goods_price FROM tdb_goods AS g -> INNER JOIN tdb_goods_cates AS c ON g.cate_id=c.cate_id -> IN 阅读全文
摘要:
1、MySQL在SELECT语句、多表更新、多表删除语句中支持JOIN操作。 语法结构 table_reference {[INNER |CROSS] JOIN} | {LEFT|RIGHT} [OUTER] JOIN} table_reference ON conditional_expr(on后 阅读全文
摘要:
1、显示(查看)创建的数据表的结构。 mysql> SHOW COLUMNS FROM tdb_goods_cates; + -+ --+ + + + -+| Field | Type | Null | Key | Default | Extra |+ + -+ + + + --+| cate_id 阅读全文