//联系人:石虎QQ: 1224614774昵称:嗡嘛呢叭咪哄

/*简单约束*/

CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER);

CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOTNULL, age INTEGER NOTNULL);

CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT UNIQUE, age INTEGER);

CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER DEFAULT1);

/*分页*/

SELECT * FROM t_student ORDER BY id ASC LIMIT30,10;

/*排序*/

SELECT * FROM t_student WHERE score >50ORDER BY age DESC;

SELECT * FROM t_student WHERE score <50ORDER BY age ASC , score DESC;

/*计量*/

SELECT COUNT(*) FROM t_student WHERE age >50;

/*别名*/

SELECT name as myName, age as myAge, score as myScore FROM t_student;

SELECT name myName, age myAge, score myScore FROM t_student;

SELECT s.name myName, s.age myAge, s.score myScore FROM t_student s WHERE s.age >50;

/*查询*/

SELECT name, age, score FROM t_student;

SELECT * FROM t_student;

/*修改指定数据*/

UPDATE t_student SET name ='MM'WHERE age =10;

UPDATE t_student SET name ='WW'WHERE age is7;

UPDATE t_student SET name ='XXOO'WHERE age <20;

UPDATE t_student SET name ='NNMM'WHERE age <50and score >10;

/*删除数据*/

DELETE FROM t_student;

/*更新数据*/

UPDATE t_student SET name ='gq';

/*插入数据*/

INSERT INTO t_student(name, age) VALUES('hml2',32);

INSERT INTO t_student(name) VALUES('hml2');

INSERT INTO t_student(age, name) VALUES(33,'hml3');

/*插入数据*/

INSERT INTO t_student(name, age, score) VALUES ('lee','28',100);

/*添加主键*/

CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, score REAL);

/*添加主键*/

CREATE TABLE IF NOT EXISTS t_student (id INTEGER, name TEXT, age INTEGER, score REAL, PRIMARY KEY(id));

/***********************DDL************************/

/*删除表*/

DROP TABLE IF EXISTS t_student;

DROP TABLE t_student;

/*创建表*/

CREATE TABLE IF NOT EXISTS t_student(name TEXT, age INTEGER, id INTEGER PRIMARY KEY AUTOINCREMENT);

CREATE TABLE t_student(name TEXT, age INTEGER, id INTEGER PRIMARY KEY AUTOINCREMENT);

CREATE TABLE t_student(name TEXT, age INTEGER, id INTEGER PRIMARY KEY);

CREATE TABLE t_student(name TEXT, age INTEGER, id INTEGER, PRIMARY KEY(id));

CREATE TABLE t_student(name TEXT, age INTEGER, id INTEGER );