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 GLOB 和 glob 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;