mysql建表文档_mysql建表建库
create database if not exists `dbname`;
DROP TABLE IF EXISTS `tbname`;
CREATE TABLE `tbname`(...)
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create database if not exists `dbname`;
DROP TABLE IF EXISTS `tbname`;
CREATE TABLE `tbname`(...)
表：
usr:
username
password
create table usr
(username char(15) primary key,
password char(15)
)
topic:
topicID
topicName
TContent
Ttime
TUser
create talbe topic
(topicID int auto_increment primary key,
topicName varchar(50),
TContent text,
Ttime date,
TUser char(15)
)
alter table topic
add constraint FK_TUser foreign key(TUser) references usr(username);
answerTopic
AnUser
AnTime
AnContent
topicID
create table answerTopic
(
AnTopicID int auto_increment primary key,
AnUser char(15),
Antime date ,
AnContent text,
topicID int
)
alter table answerTopic
add constraint FK_anuser foreign key(AnUser) references usr(username);
alter talbe answerTopic
add constraint FK_topicID foreign key(topicID) references topic(topicID);
drop table if exists `usr`;
create table usr
(username char(15) primary key,
password char(15)
);
drop table if exists `topic`;
create table topic
(topicID int auto_increment primary key,
topicName varchar(50),
TContent text(1000),
Ttime date,
TUser char(15)
);
drop table if exists `answerTopic`;
create table answerTopic
(
AnTopicID int auto_increment primary key,
AnUser char(15),
Antime date ,
AnContent text,
topicID int
);
alter table topic
add constraint FK_TUser foreign key(TUser) references usr(username);
alter table answerTopic
add constraint FK_anuser foreign key(AnUser) references usr(username);
alter table answerTopic
add constraint FK_topicID foreign key(topicID) references topic(topicID);
create database if not exists `dbname`; DROP TABLE IF EXISTS `tbname`; CREATE TABLE `tbname`(...) 用户登录user 查看贴子 用户发贴 回复贴子 create database if not exists `dbname`; DROP TABLE IF EXISTS `tbname`; CREATE TABLE `tbname`(...) 表： usr: username password create table usr (username char(15) primary key, password char(15) ) topic: topicID topicName TContent Ttime TUser create talbe topic (topicID int auto_increment primary key, topicName varchar(50), TContent text, Ttime date, TUser char(15) ) alter table topic add constraint FK_TUser foreign key(TUser) references usr(username); answerTopic AnUser AnTime AnContent topicID create table answerTopic ( AnTopicID int auto_increment primary key, AnUser char(15), Antime date , AnContent text, topicID int ) alter table answerTopic add constraint FK_anuser foreign key(AnUser) references usr(username); alter talbe answerTopic add constraint FK_topicID foreign key(topicID) references topic(topicID); drop table if exists `usr`; create table usr (username char(15) primary key, password char(15) ); drop table if exists `topic`; create table topic (topicID int auto_increment primary key, topicName varchar(50), TContent text(1000), Ttime date, TUser char(15) ); drop table if exists `answerTopic`; create table answerTopic ( AnTopicID int auto_increment primary key, AnUser char(15), Antime date , AnContent text, topicID int ); alter table topic add constraint FK_TUser foreign key(TUser) references usr(username); alter table answerTopic add constraint FK_anuser foreign key(AnUser) references usr(username); alter table answerTopic add constraint FK_topicID foreign key(topicID) references topic(topicID);