SQLite 语法规则

SQLite 是遵循一套独特的语法的规则和准则

这节我们先介绍基本的 SQLite 语法规则,并提供一些简单的小范例来快速入门

规则 1: 大小写不敏感

SQLite 是 不区分大小写 的。 但也有一些命令是大小写敏感的,比如 GLOBglob 有不同的含义

最佳实战: 虽然 SQLite 不区分大小写,但我们建议所有的命令和 SQLite 保留字都大写,除此之外所有的都小写,包括表名(table)

接下来的语句我们也会遵循这一点,如果有错误,谢谢你提出来

规则 2: 注释以 -- 开头

我们可以在 SQLite 中添加注释以增加其可读性。 SQLite 注释是附加的注释,他们可以出现在任何空白处,包括在表达式内和其他 SQL 语句的中间,但它们不能嵌套

SQLite的注释有两种:

  • SQL注释:以两个连续的 "-" 字符(ASCII 0x2d)开始,并扩展至下一个换行符(ASCII 0x0a)或直到输入结束,以先到者为准。

    SQL注释不能嵌套

范例:

sqlite>.help -- This is a single line comment
  • C 风格注释:C 风格的注释,以 "/" 开始,并扩展至下一个 "/" 字符对或直到输入结束,以先到者为准。

    C 风格的注释可以嵌套

范例:

sqlite>.help /* This is C like comment */

规则 3: SQLite 语句必须以分号(;)结束

所有的 SQLite 语句可以以任何关键字开始,如 SELECT、INSERT、UPDATE、DELETE、ALTER、DROP 等,但必须以分号(;)结束


SQLite 所有的命令语法使用范例

SQLite ANALYZE 语句

ANALYZE;

或者

ANALYZE database_name;

或者

ANALYZE database_name.table_name;

SQLite AND 子句

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION-1 AND CONDITION-2;

SQLite OR 子句

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION-1 OR CONDITION-2;

SQLite ALTER TABLE 语句

ALTER TABLE table_name ADD COLUMN column_def...;

SQLite ALTER TABLE RENAME TO 语句

ALTER TABLE table_name RENAME TO new_table_name;

SQLite ATTACH DATABASE 语句

ATTACH DATABASE 'DatabaseName' As 'Alias-Name';

SQLite BEGIN TRANSACTION 语句

BEGIN;
or
BEGIN EXCLUSIVE TRANSACTION;

SQLite BETWEEN 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name BETWEEN val-1 AND val-2;

SQLite COMMIT 语句:

COMMIT;

SQLite CREATE INDEX 语句:

CREATE INDEX index_name
ON table_name ( column_name COLLATE NOCASE );

SQLite CREATE UNIQUE INDEX 语句:

CREATE UNIQUE INDEX index_name
ON table_name ( column1, column2,...columnN);

SQLite CREATE TABLE 语句:

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

SQLite CREATE TRIGGER 语句:

CREATE TRIGGER database_name.trigger_name 
BEFORE INSERT ON table_name FOR EACH ROW
BEGIN 
   stmt1; 
   stmt2;
   ....
END;

SQLite CREATE VIEW 语句:

CREATE VIEW database_name.view_name  AS
SELECT statement....;

SQLite CREATE VIRTUAL TABLE 语句:

CREATE VIRTUAL TABLE database_name.table_name USING weblog( access.log );
or
CREATE VIRTUAL TABLE database_name.table_name USING fts3( );

SQLite COMMIT TRANSACTION 语句:

COMMIT;

SQLite COUNT 子句:

SELECT COUNT(column_name)
FROM   table_name
WHERE  CONDITION;

SQLite DELETE 语句:

DELETE FROM table_name
WHERE  {CONDITION};

SQLite DETACH DATABASE 语句:

DETACH DATABASE 'Alias-Name';

SQLite DISTINCT 子句:

SELECT DISTINCT column1, column2....columnN
FROM   table_name;

SQLite DROP INDEX 语句:

DROP INDEX database_name.index_name;

SQLite DROP TABLE 语句:

DROP TABLE database_name.table_name;

SQLite DROP VIEW 语句:

DROP VIEW view_name;

SQLite DROP TRIGGER 语句:

DROP TRIGGER trigger_name

SQLite EXISTS 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name EXISTS (SELECT * FROM   table_name );

SQLite EXPLAIN 语句:

EXPLAIN INSERT statement...;
or 
EXPLAIN QUERY PLAN SELECT statement...;

SQLite GLOB 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name GLOB { PATTERN };

SQLite GROUP BY 子句:

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name;

SQLite HAVING 子句:

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name
HAVING (arithematic function condition);

SQLite INSERT INTO 语句:

INSERT INTO table_name( column1, column2....columnN)
VALUES ( value1, value2....valueN);

SQLite IN 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name IN (val-1, val-2,...val-N);

SQLite Like 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name LIKE { PATTERN };

SQLite NOT IN 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name NOT IN (val-1, val-2,...val-N);

SQLite ORDER BY 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION
ORDER BY column_name {ASC|DESC};

SQLite PRAGMA 语句:

PRAGMA pragma_name;

范例

PRAGMA page_size;
PRAGMA cache_size = 1024;
PRAGMA table_info(table_name);

SQLite RELEASE SAVEPOINT 语句:

RELEASE savepoint_name;

SQLite REINDEX 语句:

REINDEX collation_name;
REINDEX database_name.index_name;
REINDEX database_name.table_name;

SQLite ROLLBACK 语句:

ROLLBACK;
ROLLBACK TO SAVEPOINT savepoint_name;

SQLite SAVEPOINT 语句:

SAVEPOINT savepoint_name;

SQLite SELECT 语句

SELECT column1, column2....columnN
FROM   table_name;

SQLite UPDATE 语句

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

SQLite VACUUM 语句:

VACUUM;

SQLite WHERE 子句

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION;

SQLite 基础教程

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