PostgreSQL语法
本章提供了PostgreSQL的SQL命令，这些命令的准确语法规则。这组命令是从psql的命令行工具。上一节我们已经安装Postgres，直接打开psql：
Program Files > PostgreSQL 9.2 > SQL Shell(psql).
使用psql的时候，可以生成完整的命令列表使用的 help命令。对于一个特定的命令的语法使用下面的命令：
postgres-# help <command_name>
SQL语句
一个SQL语句，包括令牌，每个令牌可以代表一个关键字，标识符，带引号的标识符，常量，或特殊的字符符号。以下表格使用简单的SELECT语句来说明一个基本的，完整的SQL语句及其组件。
| SELECT | id, name | FROM | states | |
|---|---|---|---|---|
| Token Type | Keyword | Identifiers | Keyword | Identifier |
| Description | Command | Id and name columns | Clause | Table name |
PostgreSQL的SQL命令
ABORT
中止当前事务。
ABORT [ WORK | TRANSACTION ]
ALTER AGGREGATE
更改聚合函数的定义。
ALTER AGGREGATE name ( type ) RENAME TO new_name ALTER AGGREGATE name ( type ) OWNER TO new_owner
ALTER CONVERSION
更改一个转换的定义。
ALTER CONVERSION name RENAME TO new_name
ALTER CONVERSION name OWNER TO new_owner
ALTER DATABASE
更改数据库的具体参数。
ALTER DATABASE name SET parameter { TO | = } { value | DEFAULT } ALTER DATABASE name RESET parameter ALTER DATABASE name RENAME TO new_name ALTER DATABASE name OWNER TO new_owner
ALTER DOMAIN
变更的定义域的具体参数。
ALTER DOMAIN name { SET DEFAULT expression | DROP DEFAULT } ALTER DOMAIN name { SET | DROP } NOT NULL ALTER DOMAIN name ADD domain_constraint ALTER DOMAIN name DROP CONSTRAINT constraint_name [ RESTRICT | CASCADE ] ALTER DOMAIN name OWNER TO new_owner
ALTER FUNCTION
改变它的定义了一个函数。
ALTER FUNCTION name ( [ type [, ...] ] ) RENAME TO new_name ALTER FUNCTION name ( [ type [, ...] ] ) OWNER TO new_owner
ALTER GROUP
更改用户组
ALTER GROUP groupname ADD USER username [, ... ] ALTER GROUP groupname DROP USER username [, ... ] ALTER GROUP groupname RENAME TO new_name
ALTER INDEX
更改索引的定义
ALTER INDEX name OWNER TO new_owner
ALTER INDEX name SET TABLESPACE indexspace_name
ALTER INDEX name RENAME TO new_name
ALTER LANGUAGE
更改程序语言的定义.
ALTER LANGUAGE name RENAME TO new_name
ALTER OPERATOR
更改操作员的定义.
ALTER OPERATOR name ( { lefttype | NONE } , { righttype | NONE } ) OWNER TO new_owner
ALTER OPERATOR CLASS
改变一个操作符的定义.
ALTER OPERATOR CLASS name USING index_method RENAME TO new_name
ALTER OPERATOR CLASS name USING index_method OWNER TO new_owner
ALTER SCHEMA
更改一个模式的定义.
ALTER SCHEMA name RENAME TO new_name
ALTER SCHEMA name OWNER TO new_owner
ALTER SEQUENCE
更改序列发生器的定义.
ALTER SEQUENCE name [ INCREMENT [ BY ] increment ] [ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ] [ RESTART [ WITH ] start ] [ CACHE cache ] [ [ NO ] CYCLE ]
ALTER TABLE
更改的表的定义.
ALTER TABLE [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ ONLY ] name [ * ] RENAME [ COLUMN ] column TO new_column ALTER TABLE name RENAME TO new_name
动作是以下行之一:
ADD [ COLUMN ] column_type [ column_constraint [ ... ] ] DROP [ COLUMN ] column [ RESTRICT | CASCADE ] ALTER [ COLUMN ] column TYPE type [ USING expression ] ALTER [ COLUMN ] column SET DEFAULT expression ALTER [ COLUMN ] column DROP DEFAULT ALTER [ COLUMN ] column { SET | DROP } NOT NULL ALTER [ COLUMN ] column SET STATISTICS integer ALTER [ COLUMN ] column SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN } ADD table_constraint DROP CONSTRAINT constraint_name [ RESTRICT | CASCADE ] CLUSTER ON index_name SET WITHOUT CLUSTER SET WITHOUT OIDS OWNER TO new_owner SET TABLESPACE tablespace_name
ALTER TABLESPACE
更改一个表空间的定义.
ALTER TABLESPACE name RENAME TO new_name
ALTER TABLESPACE name OWNER TO new_owner
ALTER TRIGGER
改变一个触发器的定义.
ALTER TRIGGER name ON table RENAME TO new_name
ALTER TYPE
Change the definition of a type.
ALTER TYPE name OWNER TO new_owner
ALTER USER
更改数据库用户帐户
ALTER USER name [ [ WITH ] option [ ... ] ] ALTER USER name RENAME TO new_name ALTER USER name SET parameter { TO | = } { value | DEFAULT } ALTER USER name RESET parameter
选项可以是:
[ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password' | CREATEDB | NOCREATEDB | CREATEUSER | NOCREATEUSER | VALID UNTIL 'abstime'
ANALYZE
收集数据库的统计信息.
ANALYZE [ VERBOSE ] [ table [ (column [, ...] ) ] ]
BEGIN
Start a transaction block.
BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]
transaction_mode是其中一个:
ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED } READ WRITE | READ ONLY
CHECKPOINT
强制事务处理日志检查点.
CHECKPOINT
CLOSE
关闭游标.
CLOSE name
CLUSTER
根据索引集群表.
CLUSTER index_name ON table_name
CLUSTER table_name
CLUSTER
COMMENT
定义或改变一个对象的注释.
COMMENT ON { TABLE object_name | COLUMN table_name.column_name | AGGREGATE agg_name (agg_type) | CAST (source_type AS target_type) | CONSTRAINT constraint_name ON table_name | CONVERSION object_name | DATABASE object_name | DOMAIN object_name | FUNCTION func_name (arg1_type, arg2_type, ...) | INDEX object_name | LARGE OBJECT large_object_oid | OPERATOR op (left_operand_type, right_operand_type) | OPERATOR CLASS object_name USING index_method | [ PROCEDURAL ] LANGUAGE object_name | RULE rule_name ON table_name | SCHEMA object_name | SEQUENCE object_name | TRIGGER trigger_name ON table_name | TYPE object_name | VIEW object_name } IS 'text'
COMMIT
提交当前事务.
COMMIT [ WORK | TRANSACTION ]
COPY
Copy data between a file and a table.
COPY table_name [ ( column [, ...] ) ] FROM { 'filename' | STDIN } [ [ WITH ] [ BINARY ] [ OIDS ] [ DELIMITER [ AS ] 'delimiter' ] [ NULL [ AS ] 'null string' ] [ CSV [ QUOTE [ AS ] 'quote' ] [ ESCAPE [ AS ] 'escape' ] [ FORCE NOT NULL column [, ...] ] COPY table_name [ ( column [, ...] ) ] TO { 'filename' | STDOUT } [ [ WITH ] [ BINARY ] [ OIDS ] [ DELIMITER [ AS ] 'delimiter' ] [ NULL [ AS ] 'null string' ] [ CSV [ QUOTE [ AS ] 'quote' ] [ ESCAPE [ AS ] 'escape' ] [ FORCE QUOTE column [, ...] ]
CREATE AGGREGATE
Define a new aggregate function.
CREATE AGGREGATE name ( BASETYPE = input_data_type, SFUNC = sfunc, STYPE = state_data_type [ , FINALFUNC = ffunc ] [ , INITCOND = initial_condition ] )
CREATE CAST
Define a new cast.
CREATE CAST (source_type AS target_type) WITH FUNCTION func_name (arg_types) [ AS ASSIGNMENT | AS IMPLICIT ] CREATE CAST (source_type AS target_type) WITHOUT FUNCTION [ AS ASSIGNMENT | AS IMPLICIT ]
CREATE CONSTRAINT TRIGGER
定义一个新的约束触发器
CREATE CONSTRAINT TRIGGER name AFTER events ON table_name constraint attributes FOR EACH ROW EXECUTE PROCEDURE func_name ( args )
CREATE CONVERSION
定义一个新的转换
CREATE [DEFAULT] CONVERSION name FOR source_encoding TO dest_encoding FROM func_name
CREATE DATABASE
创建一个新的数据库.
CREATE DATABASE name [ [ WITH ] [ OWNER [=] db_owner ] [ TEMPLATE [=] template ] [ ENCODING [=] encoding ] [ TABLESPACE [=] tablespace ] ]
CREATE DOMAIN
定义一个新的域.
CREATE DOMAIN name [AS] data_type [ DEFAULT expression ] [ constraint [ ... ] ]
Where constraint is:
[ CONSTRAINT constraint_name ] { NOT NULL | NULL | CHECK (expression) }
CREATE FUNCTION
定义一个新的函数.
CREATE [ OR REPLACE ] FUNCTION name ( [ [ arg_name ] arg_type [, ...] ] ) RETURNS ret_type { LANGUAGE lang_name | IMMUTABLE | STABLE | VOLATILE | CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT | [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER | AS 'definition' | AS 'obj_file', 'link_symbol' } ... [ WITH ( attribute [, ...] ) ]
CREATE GROUP
定义一个新的用户组.
CREATE GROUP name [ [ WITH ] option [ ... ] ] Where option can be: SYSID gid | USER username [, ...]
CREATE INDEX
定义一个新的索引.
CREATE [ UNIQUE ] INDEX name ON table [ USING method ] ( { column | ( expression ) } [ opclass ] [, ...] ) [ TABLESPACE tablespace ] [ WHERE predicate ]
CREATE LANGUAGE
定义一个新的程序语言.
CREATE [ TRUSTED ] [ PROCEDURAL ] LANGUAGE name HANDLER call_handler [ VALIDATOR val_function ]
CREATE OPERATOR
定义一个新的操作.
CREATE OPERATOR name ( PROCEDURE = func_name [, LEFTARG = left_type ] [, RIGHTARG = right_type ] [, COMMUTATOR = com_op ] [, NEGATOR = neg_op ] [, RESTRICT = res_proc ] [, JOIN = join_proc ] [, HASHES ] [, MERGES ] [, SORT1 = left_sort_op ] [, SORT2 = right_sort_op ] [, LTCMP = less_than_op ] [, GTCMP = greater_than_op ] )
CREATE OPERATOR CLASS
定义一个新的操作符类.
CREATE OPERATOR CLASS name [ DEFAULT ] FOR TYPE data_type USING index_method AS { OPERATOR strategy_number operator_name [ ( op_type, op_type ) ] [ RECHECK ] | FUNCTION support_number func_name ( argument_type [, ...] ) | STORAGE storage_type } [, ... ]
CREATE RULE
定义一个新的重写规则.
CREATE [ OR REPLACE ] RULE name AS ON event TO table [ WHERE condition ] DO [ ALSO | INSTEAD ] { NOTHING | command | ( command ; command ... ) }
CREATE SCHEMA
定义一个新的模式.
CREATE SCHEMA schema_name [ AUTHORIZATION username ] [ schema_element [ ... ] ] CREATE SCHEMA AUTHORIZATION username [ schema_element [ ... ] ]
CREATE SEQUENCE
定义一个新的序列发生器.
CREATE [ TEMPORARY | TEMP ] SEQUENCE name [ INCREMENT [ BY ] increment ] [ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ] [ START [ WITH ] start ] [ CACHE cache ] [ [ NO ] CYCLE ]
CREATE TABLE
定义一个新表.
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name ( { column_name data_type [ DEFAULT default_expr ] [ column_constraint [ ... ] ] | table_constraint | LIKE parent_table [ { INCLUDING | EXCLUDING } DEFAULTS ] } [, ... ] ) [ INHERITS ( parent_table [, ... ] ) ] [ WITH OIDS | WITHOUT OIDS ] [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ] [ TABLESPACE tablespace ]Where column_constraint is:
[ CONSTRAINT constraint_name ] { NOT NULL | NULL | UNIQUE [ USING INDEX TABLESPACE tablespace ] | PRIMARY KEY [ USING INDEX TABLESPACE tablespace ] | CHECK (expression) | REFERENCES ref_table [ ( ref_column ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE action ] [ ON UPDATE action ] } [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
And table_constraint is:
[ CONSTRAINT constraint_name ] { UNIQUE ( column_name [, ... ] ) [ USING INDEX TABLESPACE tablespace ] | PRIMARY KEY ( column_name [, ... ] ) [ USING INDEX TABLESPACE tablespace ] | CHECK ( expression ) | FOREIGN KEY ( column_name [, ... ] ) REFERENCES ref_table [ ( ref_column [, ... ] ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE action ] [ ON UPDATE action ] } [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
CREATE TABLE AS
定义一个新表的查询结果。
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name [ (column_name [, ...] ) ] [ [ WITH | WITHOUT ] OIDS ] AS query
CREATE TABLESPACE
定义一个新的表空间。
CREATE TABLESPACE tablespace_name [ OWNER username ] LOCATION 'directory'
CREATE TRIGGER
定义一个新的触发器。
CREATE TRIGGER name { BEFORE | AFTER } { event [ OR ... ] } ON table [ FOR [ EACH ] { ROW | STATEMENT } ] EXECUTE PROCEDURE func_name ( arguments )
CREATE TYPE
定义一个新的数据类型。
CREATE TYPE name AS ( attribute_name data_type [, ... ] ) CREATE TYPE name ( INPUT = input_function, OUTPUT = output_function [ , RECEIVE = receive_function ] [ , SEND = send_function ] [ , ANALYZE = analyze_function ] [ , INTERNALLENGTH = { internal_length | VARIABLE } ] [ , PASSEDBYVALUE ] [ , ALIGNMENT = alignment ] [ , STORAGE = storage ] [ , DEFAULT = default ] [ , ELEMENT = element ] [ , DELIMITER = delimiter ] )
CREATE USER
定义一个新的数据库用户帐户。
CREATE USER name [ [ WITH ] option [ ... ] ]
选项可以是：
SYSID uid | [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password' | CREATEDB | NOCREATEDB | CREATEUSER | NOCREATEUSER | IN GROUP group_name [, ...] | VALID UNTIL 'abs_time'
CREATE VIEW
定义一个新的视图。
CREATE [ OR REPLACE ] VIEW name [ ( column_name [, ...] ) ] AS query
