1.创建数据库

//存在会打开，不存在，会创建
sqlite3 TEST.sqlite

//查看数据库表概要 sqlite_master 一个特殊的表，储存了数据的相关信息
.schema sqlite_master

//注释
.help -- 这是帮助信息
.help /*这是帮助信息*/

//检查sqlite数据库列表
.databases

//查看数据库中的表
.tables

//查看建表信息
.schema
.schema Person

//退出sqlite
.quit

//导出完整数据库到文本文件中
sqlite3 TEST.sqlite .dump > TEST.sql

//导入文本文件中数据到数据库
sqlite3 TEST.sqlite < TEST.sql

//附加数据库，如果存在SQLite.sqlite数据库，则把SQLite.sqlite和new绑定。不存在，则会创建，然后绑定。temp和main不能被附加。
ATTACH DATABASE 'SQLite.sqlite' As 'new';

//分离数据库
DETACH DATABASE 'new';

//终端设置
.header on
.mode column
.timer on
.width 10,20,30 //设置输出宽度

默认不区分大小写，但是有部分特殊的是大小写敏感的。比如GLOB和glob。

2.创建表

//语法
CREATE TABLE database_name.table_name(
   column1 datatype  PRIMARY KEY(one or more columns),
   column2 datatype,
   column3 datatype,
   .....
   columnN datatype,
);

//使用
CREATE TABLE Person (
id INT PRIMARK KEY NOT NULL, 
name TEXT NOT NULL, 
age INT NOT NULL, 
score INT);

3.删除表

//语法
DROP TABLE database_name.table_name;

//使用
DROP TABLE Student;

4.插入

//语法1
INSERT INTO TABLE_NAME [(column1, column2, column3,...columnN)]  
VALUES (value1, value2, value3,...valueN);
//语法3
INSERT INTO TABLE_NAME VALUES (value1,value2,value3,...valueN);

//使用
INSERT INTO Person (id, name, age, score) VALUES (0,"zs",10,99);

INSERT INTO Person VALUES (1,"ls",11,98);

INSERT INTO Person (id, name, age) VALUES (2,"ww",11);

//通过拷贝，将一个表拷入另外一个表中
INSERT INTO first_table_name [(column1, column2, ... columnN)] 
   SELECT column1, column2, ...columnN 
   FROM second_table_name
   [WHERE condition];

//使用
INSERT INTO Student (id, name, age, score) SELECT id, name, age, score FROM Person;

5.查询

//基本语法，查询具体字段
SELECT column1, column2, columnN FROM table_name;
//简化，查询所有
SELECT * FROM table_name;

//使用
SELECT id,name,age,score FROM Student;
SELECT * FROM Student;

//查询数据库中的表
SELECT tbl_name FROM sqlite_master WHERE type = 'table';

//列出表的完整信息
SELECT sql FROM sqlite_master WHERE type = 'table' AND tbl_name = 'Student';

6.运算符

//=
SELECT * FROM Student WHERE age = 10;

//>
SELECT * FROM Student WHERE age > 10;

//!=
SELECT * FROM Student WHERE age != 10;

//<>
SELECT * FROM Student WHERE age <> 10;

//>=
SELECT * FROM Student WHERE age >= 10;

//AND
SELECT * FROM Student WHERE age < 12 AND id < 2;

//OR
SELECT * FROM Student WHERE age = 11 OR id = 0;

//IS NOT NULL
SELECT * FROM Student WHERE score IS NOT NULL;

//LIKE
SELECT * FROM Student WHERE name LIKE "Z%";

//GLOB
SELECT * FROM Student WHERE name GLOB "z*";

//IN
SELECT * FROM Student WHERE age IN (10,11);

//NOT IN
SELECT * FROM Student WHERE age NOT IN (10,13);

//BETWEEN AND
SELECT * FROM Student WHERE age BETWEEN 9 AND 12;

//EXISTS
SELECT * FROM Student WHERE EXISTS (SELECT AGE FROM Student WHERE age > 10);

//子查询
SELECT * FROM Student WHERE age > (SELECT age FROM Student WHERE id >= 0);

//AVG()
SELECT AVG(age) FROM Student;

//SUM()
SELECT SUM(age) FROM Student;

//COUNT()
SELECT COUNT(age) FROM Student;

//CURRENT_TIMESTAMP
SELECT CURRENT_TIMESTAMP;

7.更新

//语法
UPDATE table_name
SET column1 = value1, column2 = value2...., columnN = valueN
WHERE [condition];

//使用
UPDATE Student SET score = 88 WHERE id = 2;

//更新全部
UPDATE Student SET color = "red", score = 90;

8.删除

//语法
DELETE FROM table_name
WHERE [condition];

//使用
DELETE FROM Student WHERE id = 2;

//删除全部
ELETE FROM Student;

//清除未使用的空间，建议使用删除全部后，都清除一次
VACUUM;

9.LIKE

//匹配上了，返回1
//%表示0个或者多个
//_一个
SELECT * FROM Person WHERE name LIKE "z%";
SELECT * FROM Person WHERE name LIKE "z_";

10.GLOB

//同LIKE
//*表示0个或者多个
//?一个
SELECT * FROM Person WHERE name GLOB "l*";
SELECT * FROM Person WHERE name GLOB "l?";

11.LIMIT

//限制返回数量
//语法
SELECT column1, column2, columnN 
FROM table_name
LIMIT [no of rows]

SELECT column1, column2, columnN 
FROM table_name
LIMIT [no of rows] OFFSET [row num]

//使用
SELECT * FROM Person LIMIT 1;
SELECT * FROM Person LIMIT 1 OFFSET 1;

12.ORDER BY

排序

//语法
SELECT column-list 
FROM table_name 
[WHERE condition] 
[ORDER BY column1, column2, .. columnN] [ASC | DESC];

//使用
SELECT * FROM Person ORDER BY score;//默认ASC升序
SELECT * FROM Person ORDER BY score DESC;//降序
SELECT * FROM Person ORDER BY score, name ASC;//按照score,name排序

13.GROUP BY

分组

//语法
SELECT column-list
FROM table_name
WHERE [ conditions ]
GROUP BY column1, column2....columnN
ORDER BY column1, column2....columnN

//使用
SELECT * FROM Person GROUP BY name;
SELECT name,score FROM Person GROUP BY name ORDER BY name DESC;

14.HAVING

过滤

//语法
SELECT column1, column2
FROM table1, table2
WHERE [ conditions ]
GROUP BY column1, column2
HAVING [ conditions ]
ORDER BY column1, column2

//使用
SELECT * FROM Person GROUP BY name HAVING count(name) > 1;

15.DISTINCT

清除重复

//语法
SELECT DISTINCT column1, column2,.....columnN 
FROM table_name
WHERE [condition]

//使用
SELECT DISTINCT name FROM Person;

16.各种语句在SELECT中的位置

SELECT
FROM
WHERE
GROUP BY
HAVING
ORDER BY

17.约束

//NOT NULL，不能为空
CREATE TABLE Person (id INT PRIMARK KEY NOT NULL, name TEXT NOT NULL, age INT NOT NULL, score INT);

//DEFAULT，提供一个默认值
CREATE TABLE Student (id INT PRIMARK KEY NOT NULL, name TEXT DEFAULT "_");

//PRIMARY KEY，主键，不能重复
CREATE TABLE Student (id INT PRIMARK KEY NOT NULL, name TEXT DEFAULT "_");

//CHECK，约束，检查输入值，不满足不能输入到表
CREATE TABLE Teacher (id INT PRIMARK KEY NOT NULL, age INT CHECK(age>10));

18.结合

//交叉连接，两者相互叠加
SELECT ... FROM table1 CROSS JOIN table2 ...

//使用
SELECT name,height,age FROM Person CROSS JOIN TEACHER;


//内连接，按照条件合并
SELECT ... FROM table1 [INNER] JOIN table2 ON conditional_expression ...
SELECT ... FROM table1 JOIN table2 USING ( column1 ,... ) ...
SELECT ... FROM table1 NATURAL JOIN table2...

//使用
SELECT name,height FROM Person INNER JOIN TEACHER ON Person.id = TEACHER.id;

//外连接
SELECT ... FROM table1 LEFT OUTER JOIN table2 ON conditional_expression ...
SELECT ... FROM table1 LEFT OUTER JOIN table2 USING ( column1 ,... ) ...

//使用
SELECT name,height FROM Person LEFT OUTER JOIN TEACHER ON Person.id = TEACHER.id;

19.NULL

表示一个值的缺失，在字段中显示为一个空白的值。

//语法
CREATE TABLE COMPANY(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL,
   ADDRESS        CHAR(50),
   SALARY         REAL
);

20.别名

可以暂时把表或者列重命名，不会改变数据库表名。

//语法-表
SELECT column1, column2....
FROM table_name AS alias_name
WHERE [condition];
//列
SELECT column_name AS alias_name
FROM table_name
WHERE [condition];


SELECT C.id,C.name,C.age,D.height
FROM Person as C, TEACHER as D
 WHERE C.id = D.id;

SELECT C.id AS ID,C.name AS NAME,D.height AS HEIGHT
FROM Person AS C, TEACHER AS D
WHERE C.id = D.id;

21.触发器

当数据库发生指定事件时，触发器会被调用。

• 发生DELETE/INSERT/UPDATE时触发，或者一个、多个指定表的列发生更新时触发
• 只支持FOR EACH ROW触发
• 没提供WHEN子句，会对所有执行SQL语句触发
• BEFORE或AFTER关键字决定何时执行触发器
• 当触发器关联的表删除时，自动删除触发器
• 要修改的表必须存在同一数据库
• 一个特殊的SQL函数RAISE可以用于触发器程序抛出异常

//语法
CREATE  TRIGGER trigger_name [BEFORE|AFTER] event_name 
ON table_name
BEGIN
 -- Trigger logic goes here....
END;

//使用 a触发器的标示符
CREATE TRIGGER a AFTER INSERT ON Person
BEGIN
INSERT INTO AUDIT(id,date) VALUES(new.id,datetime("now"));
END;


//列出触发器
SELECT name FROM sqlite_master WHERE type = "trigger";

//特定表的触发器
SELECT name FROM sqlite_master WHERE type = "trigger" AND tbl_name = "Person";

//删除触发器 audit_log是触发器标示符
DROP TRIGGER audit_log;

22.索引

一种特殊的查找表，用于加快数据的检索。
能够加快SELECT和WHERE子句的速度，但是会减慢UPDATE和INSERT的输入。

//基本语法
CREATE INDEX index_name ON table_name;

//单列索引
CREATE INDEX index_name
ON table_name (column_name);

//唯一索引
CREATE UNIQUE INDEX index_name
on table_name (column_name);

//组合索引
CREATE INDEX index_name
on table_name (column1, column2);

//使用
CREATE INDEX id_id ON Person(id);

//查看表的索引
.indices Person

//查看数据库所有索引
SELECT * FROM sqlite_master WHERE type = "index";

//删除索引
DROP INDEX index_name;

不应该使用索引的情况：

• 表内容较小
• 大批量插入和更新
• 含有大量NULL值的列上
• 频繁操作的列上

23.ALERT

可以重命名表和增加新的列。

//语法-重命名
ALTER TABLE database_name.table_name RENAME TO new_table_name;
//语法-添加新的列
ALTER TABLE database_name.table_name ADD COLUMN column_def...;

//使用-重命名
ALTER TABLE TEACHER RENAME TO Teachers;
//使用-添加新的列
ALTER TABLE Teachers ADD COLUMN sex char(1);

24.视图

可以创建出一个视图，该视图和表一样，但是不能够执行DELETE/INSERT/UPDATE语句，但是可以添加触发器。

//语法
CREATE [TEMP | TEMPORARY] VIEW view_name AS
SELECT column1, column2.....
FROM table_name
WHERE [condition];

//使用-创建
CREATE VIEW PERSONVIEW AS SELECT * FROM Person;

//查询
 select * FROM PERSONVIEW;

//删除
drop view PERSONVIEW;

25.子查询

可以与SELECT/INSERT/UPDATE/DELETE一起使用，进一步限制要检索的数据。

• 子查询必须用括号括起来
• 子查询在SELECT中只能有一个列
• ORDER BY 不能用在子查询中
• 子查询返回多余一行，智能与多值运算符一起使用，如IN
• BETWEEN不能与子查询一起使用，但可以在子查询内使用

//语法-SELECT
SELECT column_name [, column_name ]
FROM   table1 [, table2 ]
WHERE  column_name OPERATOR
      (SELECT column_name [, column_name ]
      FROM table1 [, table2 ]
      [WHERE])


//使用
SELECT * FROM Person WHERE id IN (SELECT id FROM Person WHERE id > 1);

//语法-INSERT
INSERT INTO table_name [ (column1 [, column2 ]) ]
           SELECT [ *|column1 [, column2 ]
           FROM table1 [, table2 ]
           [ WHERE VALUE OPERATOR ]

//使用
INSERT INTO PersonT SELECT * FROM Person WHERE id IN (SELECT id FROM Person);

//语法-UPDATE
UPDATE table
SET column_name = new_value
[ WHERE OPERATOR [ VALUE ]
   (SELECT COLUMN_NAME
   FROM TABLE_NAME)
   [ WHERE) ]


//语法-DELETE
DELETE FROM TABLE_NAME
[ WHERE OPERATOR [ VALUE ]
   (SELECT COLUMN_NAME
   FROM TABLE_NAME)
   [ WHERE) ]

26.自动递增

用于表中的字段自动的递增

//语法
CREATE TABLE table_name(
   column1 INTEGER AUTOINCREMENT,
   column2 datatype,
   column3 datatype,
   .....
   columnN datatype,
);

//使用
CREATE TABLE C (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL);

27.SQLite注入

用户通过输入，并将输入内容插入到 SQLite 数据库中，这个时候您就面临着一个被称为 SQL 注入的安全问题。注入通常在请求用户输入时发生，比如需要用户输入姓名，但用户却输入了一个 SQLite 语句，而这语句就会在不知不觉中在数据库上运行。

防治办法就是，插入前进行判断。

28.EXPLAIN

可用EXPLAIN来描述表的细节。

//语法
EXPLAIN [SQLite Query]
EXPLAIN  QUERY PLAN [SQLite Query]

29.日期和时间

YYYY年
MM月
DD日
HH时
MM分
SS秒
SSS毫秒
now当前

30.常用函数