SQLite详解，案例，手册

SQLite 存储类型

1.NULL

2.INTEGER

3.REAL

4.TEXT

5.BLOB

创建表

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

删除数据表

DROP TABLE COMPANY;

插入数据表

1.方式一

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (1, 'Paul', 32, 'California', 20000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (2, 'Allen', 25, 'Texas', 15000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (5, 'David', 27, 'Texas', 85000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 );

2.方式二

INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 );

查询数据表

1.查询全部

SELECT * FROM COMPANY;

2.查询部分

SELECT ID, NAME, SALARY FROM COMPANY;

SQLite 算术运算符

select 10 + 20;
select 10 - 20;
select 10 * 20;
select 10 / 5;
select 12 %  5;

SQLite 比较运算符

SELECT * FROM COMPANY WHERE SALARY > 50000;
SELECT * FROM COMPANY WHERE SALARY = 20000;
SELECT * FROM COMPANY WHERE SALARY != 20000;
SELECT * FROM COMPANY WHERE SALARY <> 20000;
SELECT * FROM COMPANY WHERE SALARY >= 65000;

SQLite 逻辑运算符

SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000;
SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000;
SELECT * FROM COMPANY WHERE AGE IS NOT NULL;
SELECT * FROM COMPANY WHERE NAME LIKE 'Ki%';
SELECT * FROM COMPANY WHERE NAME GLOB 'Ki*';
SELECT * FROM COMPANY WHERE AGE IN ( 25, 27 );
SELECT * FROM COMPANY WHERE AGE NOT IN ( 25, 27 );
SELECT * FROM COMPANY WHERE AGE BETWEEN 25 AND 27;
SELECT AGE FROM COMPANY WHERE EXISTS (SELECT AGE FROM COMPANY WHERE SALARY > 65000);
SELECT * FROM COMPANY WHERE AGE > (SELECT AGE FROM COMPANY WHERE SALARY > 65000);

数值表达式

SELECT COUNT(*) AS "RECORDS" FROM COMPANY;

更新数据

UPDATE COMPANY SET ADDRESS = 'Texas' WHERE ID = 6;  -- 按条件修改
UPDATE COMPANY SET ADDRESS = 'Texas', SALARY = 20000.00; -- 修改全部

删除数据

DELETE FROM COMPANY WHERE ID = 7; -- 按条件删除
DELETE FROM COMPANY; -- 删除全部

LIKE查询

SELECT * FROM COMPANY WHERE AGE  LIKE '2%'; -- 查询2开头的年龄数据
SELECT * FROM COMPANY WHERE ADDRESS  LIKE '%-%'; -- 查询文本里包含一个连字符（-）的所有记录
SELECT * FROM COMPANY WHERE AGE  LIKE '_5'; -- 查询第二位是5的年龄数据

GLOB查询

like：百分号（%）代表零个、一个或多个数字或字符。下划线（_）代表一个单一的数字或字符。

glob：星号（*）代表零个、一个或多个数字或字符。问号（?）代表一个单一的数字或字符。

SELECT * FROM COMPANY WHERE AGE  GLOB '2*';
SELECT * FROM COMPANY WHERE ADDRESS  GLOB '*-*';

Limit 子句

SELECT * FROM COMPANY LIMIT 6; -- 获取6条记录
SELECT * FROM COMPANY LIMIT 3 OFFSET 2; -- 获取第二行之后的三条记录

Order By

SELECT * FROM COMPANY ORDER BY SALARY ASC;
SELECT * FROM COMPANY ORDER BY NAME, SALARY ASC;
SELECT * FROM COMPANY ORDER BY NAME DESC;

Group By

SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME;
SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME ORDER BY NAME DESC;

Having

SELECT * FROM COMPANY GROUP BY name HAVING count(name) > 2; -- 对group by之后进行筛选

DISTINCT

SELECT DISTINCT name FROM COMPANY; -- 去除重复记录

SQLite 约束

1.NOT NULL

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

2.DEFAULT 约束

CREATE TABLE COMPANY(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL,
   ADDRESS        CHAR(50),
   SALARY         REAL    DEFAULT 50000.00
);

3.UNIQUE 约束

CREATE TABLE COMPANY(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL UNIQUE,
   ADDRESS        CHAR(50),
   SALARY         REAL    DEFAULT 50000.00
);

4.PRIMARY KEY 约束

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

5.CHECK 约束

CHECK 约束启用输入一条记录要检查值的条件。如果条件值为 false，则记录违反了约束，且不能输入到表。

CREATE TABLE COMPANY3(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL,
   ADDRESS        CHAR(50),
   SALARY         REAL    CHECK(SALARY > 0)
);

Joins

交叉连接 - CROSS JOIN
内连接 - INNER JOIN
外连接 - OUTER JOIN

准备表

  CREATE TABLE DEPARTMENT(
     ID INT PRIMARY KEY      NOT NULL,
     DEPT           CHAR(50) NOT NULL,
     EMP_ID         INT      NOT NULL
  );

  INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID)
  VALUES (1, 'IT Billing', 1 );

  INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID)
  VALUES (2, 'Engineering', 2 );

  INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID)
  VALUES (3, 'Finance', 7 );

SELECT EMP_ID, NAME, DEPT FROM COMPANY CROSS JOIN DEPARTMENT; -- 交叉连接
SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; -- 内连接
SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; -- 外连接

NULL处理

UPDATE COMPANY SET ADDRESS = NULL, SALARY = NULL where ID IN(6,7);
SELECT  ID, NAME, AGE, ADDRESS, SALARY FROM COMPANY WHERE SALARY IS NOT NULL;
SELECT  ID, NAME, AGE, ADDRESS, SALARY FROM COMPANY WHERE SALARY IS NULL;

别名

SELECT C.ID, C.NAME, C.AGE, D.DEPT
        FROM COMPANY AS C, DEPARTMENT AS D
        WHERE  C.ID = D.EMP_ID;

SELECT C.ID AS COMPANY_ID, C.NAME AS COMPANY_NAME, C.AGE, D.DEPT
        FROM COMPANY AS C, DEPARTMENT AS D
        WHERE  C.ID = D.EMP_ID;

触发器

准备表

CREATE TABLE AUDIT(
    EMP_ID INT NOT NULL,
    ENTRY_DATE TEXT NOT NULL
);

CREATE TRIGGER audit_log AFTER INSERT 
ON COMPANY
BEGIN
   INSERT INTO AUDIT(EMP_ID, ENTRY_DATE) VALUES (new.ID, datetime('now'));
END; -- 创建触发器，每增加一条数据，就插入一条数据到AUDIT中

查询已存在的触发器

SELECT name FROM sqlite_master
WHERE type = 'trigger';

SELECT name FROM sqlite_master
WHERE type = 'trigger' AND tbl_name = 'COMPANY';

DROP TRIGGER audit_log; -- 删除触发器

ALTER修改表

ALTER TABLE COMPANY RENAME TO OLD_COMPANY; -- 修改名字
ALTER TABLE OLD_COMPANY ADD COLUMN SEX char(1); -- 增加字段

视图

CREATE VIEW COMPANY_VIEW AS
SELECT ID, NAME, AGE
FROM  COMPANY; -- 创建视图

SELECT * from COMPANY_VIEW; -- 查询视图

DROP VIEW COMPANY_VIEW; -- 删除视图

事务

BEGIN;
DELETE FROM COMPANY WHERE AGE = 25;
ROLLBACK; -- 取消

BEGIN;
DELETE FROM COMPANY WHERE AGE = 25;
COMMIT;  -- 确认

子查询

SELECT * 
     FROM COMPANY 
     WHERE ID IN (SELECT ID 
                  FROM COMPANY 
                  WHERE SALARY > 45000) ; -- 查询
INSERT INTO COMPANY_BKP
     SELECT * FROM COMPANY 
     WHERE ID IN (SELECT ID 
                  FROM COMPANY) ;  -- 插入
 UPDATE COMPANY
     SET SALARY = SALARY * 0.50
     WHERE AGE IN (SELECT AGE FROM COMPANY_BKP
                   WHERE AGE >= 27 ); -- 更新

DELETE FROM COMPANY
     WHERE AGE IN (SELECT AGE FROM COMPANY_BKP
                   WHERE AGE > 27 ); -- 删除

自增

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

方法论:整理的好辛苦

posted @ 2017-05-04 19:16 TBHacker 阅读(500) 评论(0) 编辑收藏举报

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SQLite详解，案例，手册

SQLite 存储类型

创建表

删除数据表

插入数据表

查询数据表

SQLite 算术运算符

SQLite 比较运算符

SQLite 逻辑运算符

数值表达式

更新数据

删除数据

LIKE查询

GLOB查询

Limit 子句

Order By

Group By

Having

DISTINCT

SQLite 约束

Joins

NULL处理

别名

触发器

ALTER修改表

视图

事务

子查询

自增

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