◆SELECTCOUNT(*)FROMUS...... SELECT COUNT(*) FROM USER_TAB_COLUMNS WHERE TABLE_NAME=UPPER('legalentity') MYSQL中的外键: /*===============================*/ /* DBMS name: MySQL 4.0 */ /* Created on: 2005-8-9 16:38:37 */ /*===============================*/ drop table if exists Article; drop table if exists Board; drop table if exists User; /*======================================*/ /* Table: Article */ /*======================================*/ create table Article ( id int not null primary key, parent_id int, index(parent_id), foreign key (parent_id) references Article (id) , board_id int not null, index(board_id), foreign key (board_id) references Board (id) , article_type int not null, title varchar(255) not null, body text, create_by int not null, index(create_by), foreign key (create_by) references User (id) , create_time datetime not null, hits int not null, bytes int, last_update_by int not null, index(last_update_by), foreign key (last_update_by) references User (id), last_update_time datetime not null, ) type = InnoDB; /*===================================*/ /* Table: Board */ /*===================================*/ create table Board ( id int not null primary key, create_by int not null, index(create_by), foreign key (create_by) references User (id), parent_id int, index(parent_id), foreign key (parent_id) references Board (id), name varchar(50) not null, remark varchar(255), create_time datetime not null, ) type = InnoDB; /*====================================*/ /* Table: User */ /*====================================*/ create table User ( id int not null primary key, name varchar(50) not null, pwd varchar(50) not null, ) type = InnoDB; |
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