顯示數(shù)據(jù)表信息和結(jié)構(gòu): SHOW CREATE TABLE tb1;
顯示數(shù)據(jù)表列結(jié)構(gòu): SHOW COLUMNS FROM tb1;
顯示數(shù)據(jù)表全部記錄： SELECT * FROM tb1
插入記錄: INSERT tb_name [(col_name, ...)] VALUES(val,..)
設(shè)置主鍵和排序： CREATE TABLE tb3(id SMALLINT UNSIGNED AUTO_INCREMENT KEY,username VARCHAR(30));
主鍵約束唯一約束： PRIMARY KEY, UNIQUE KEY
設(shè)置默認(rèn)值：
CREATE TABLE tb6(
id SMALLINT UNSIGNED AUTO_INCREMENT KEY,
username VARCHAR(20) NOT NULL UNIQUE KEY,
sex ENUM('1','2','3') DEFAULT '3'
);
- 外鍵約束：
CREATE TABLE province(
id SMALLINT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
pname VARCHAR(20) NOT NULL
);
CREATE TABLE users(
id SMALLINT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(10) NOT NULL,
pid SMALLINT UNSIGNED,
FOREIGN KEY (pid) REFERENCES province(id)
);
SHOW INDEXES FROM province\G;
SHOW INDEXES FROM users\G;
