| 结构定义 |
| CREATE TABLE | 创建新表。 语法:
| sql-command::= | CREATE [TEMP | TEMPORARY] TABLE table-name ( column-def [, column-def]* [, constraint]* ) | | sql-command::= | CREATE [TEMP | TEMPORARY] TABLE [database-name.] table-name AS select-statement | | column-def::= | name [type] [[CONSTRAINT name] column-constraint]* | | type::= | typename | typename ( number ) | typename ( number , number ) | | column-constraint::= | NOT NULL [ conflict-clause ] | PRIMARY KEY [sort-order] [ conflict-clause ] | UNIQUE [ conflict-clause ] | CHECK ( expr ) [ conflict-clause ] | DEFAULT value | COLLATE collation-name | | constraint::= | PRIMARY KEY ( column-list ) [ conflict-clause ] | UNIQUE ( column-list ) [ conflict-clause ] | CHECK ( expr ) [ conflict-clause ] | | conflict-clause::= | ON CONFLICT conflict-algorithm |
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| CREATE VIEW | 创建一个视图(虚拟表),该表以另一种方式表示一个或多个表中的数据。 语法:
| sql-command::= | CREATE [TEMP | TEMPORARY] VIEW [database-name.] view-name AS select-statement |
例子: CREATE VIEW master_view AS SELECT * FROM sqlite_master WHERE type='view'; 说明: 创建一个名为master_view的视图,其中包括sqlite_master这个表中的所有视图表。 |
| CREATE TRIGGER | 创建触发器,触发器是一种特殊的存储过程,在用户试图对指定的表执行指定的数据修改语句时自动执行。 语法:
| sql-statement::= | CREATE [TEMP | TEMPORARY] TRIGGER trigger-name [ BEFORE | AFTER ] database-event ON [database-name .] table-name trigger-action |
| sql-statement::= | CREATE [TEMP | TEMPORARY] TRIGGER trigger-name INSTEAD OF database-event ON [database-name .] view-name trigger-action |
| database-event::= | DELETE | INSERT | UPDATE | UPDATE OF column-list |
| trigger-action::= | [ FOR EACH ROW | FOR EACH STATEMENT ] [ WHEN expression ] BEGIN trigger-step ; [ trigger-step ; ]* END |
| trigger-step::= | update-statement | insert-statement | delete-statement | select-statement |
例子: CREATE TRIGGER update_customer_address UPDATE OF address ON customers BEGIN UPDATE orders SET address = new.address WHERE customer_name = old.name; END; 说明: 创建了一个名为update_customer_address的触发器,当用户更新customers表中的address字段时,将触发并更新orders表中的address字段为新的值。 比如执行如下一条语句: UPDATE customers SET address = '1 Main St.' WHERE name = 'Jack Jones'; 数据库将自动执行如下语句: UPDATE orders SET address = '1 Main St.' WHERE customer_name = 'Jack Jones'; |
| CREATE INDEX | 为给定表或视图创建索引。 语法:
| sql-statement::= | CREATE [UNIQUE] INDEX index-name ON [database-name .] table-name ( column-name [, column-name]* ) [ ON CONFLICT conflict-algorithm ] | | column-name::= | name [ COLLATE collation-name] [ ASC | DESC ] |
例子: CREATE INDEXidx_email ON customers (email); 说明: 为customers表中的email创建一个名为idx_email的字段。 |
| 结构删除 |
| DROP TABLE | 删除表定义及该表的所有索引。 语法:
| sql-command::= | DROP TABLE [database-name.] table-name | 例子: DROP TABLE customers; |
| DROP VIEW | 删除一个视图。 语法:
| sql-command::= | DROP VIEW view-name |
例子: DROP VIEW master_view; |
| DROP TRIGGER | 删除一个触发器。 语法:
| sql-statement::= | DROP TRIGGER [database-name .] trigger-name |
例子: DROP TRIGGER update_customer_address; |
| DROP INDEX | 删除一个索引。 语法:
| sql-command::= | DROP INDEX [database-name .] index-name |
例子: DROP INDEX idx_email; |
| 数据操作 |
| INSERT | 将新行插入到表。 语法:
| sql-statement::= | INSERT [OR conflict-algorithm] INTO [database-name .] table-name [(column-list)] VALUES(value-list) | INSERT [OR conflict-algorithm] INTO [database-name .] table-name [(column-list)] select-statement |
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| UPDATE | 更新表中的现有数据。 语法:
| sql-statement::= | UPDATE [ OR conflict-algorithm ] [database-name .] table-name SET assignment [, assignment]* [WHERE expr] | | assignment::= | column-name = expr |
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| DELETE | 从表中删除行。 语法:
| sql-statement::= | DELETE FROM [database-name .] table-name [WHERE expr] |
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| SELECT | 从表中检索数据。 语法:
| sql-statement::= | SELECT [ALL | DISTINCT] result [FROM table-list] [WHERE expr] [GROUP BY expr-list] [HAVING expr] [compound-op select]* [ORDER BY sort-expr-list] [LIMIT integer [( OFFSET | , ) integer]] | | result::= | result-column [, result-column]* | | result-column::= | * | table-name . * | expr [ [AS] string ] | | table-list::= | table [join-op table join-args]* | | table::= | table-name [AS alias] | ( select ) [AS alias] | | join-op::= | , | [NATURAL] [LEFT | RIGHT | FULL] [OUTER | INNER | CROSS] JOIN | | join-args::= | [ON expr] [USING ( id-list )] | | sort-expr-list::= | expr [sort-order] [, expr [sort-order]]* | | sort-order::= | [ COLLATE collation-name ] [ ASC | DESC ] | | compound_op::= | UNION | UNION ALL | INTERSECT | EXCEPT |
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| REPLACE | 类似INSERT 语法:
| sql-statement::= | REPLACE INTO [database-name .] table-name [( column-list )] VALUES ( value-list ) | REPLACE INTO [database-name .] table-name [( column-list )] select-statement |
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