ALTER TABLE table_name DROP INDEX IF EXISTS index_name; PostgreSQL 在PostgreSQL中,DROP INDEX命令本身支持IF EXISTS子句: sql DROP INDEX IF EXISTS index_name; 注意,在PostgreSQL中,ALTER TABLE命令并不直接支持DROP INDEX IF EXISTS语法。 SQL Server 在SQL Server中,从2016版本(13.x)开始,DROP INDEX命...
ALTER TABLE [ IF EXISTS ] [ ONLY ]name[ * ]action[, ... ] ALTER TABLE [ IF EXISTS ] [ ONLY ]name[ * ] RENAME [ COLUMN ]column_nameTOnew_column_nameALTER TABLE [ IF EXISTS ] [ ONLY ]name[ * ] RENAME CONSTRAINTconstraint_nameTOnew_constraint_nameALTER TABLE [ IF EXISTS ]nameR...
PostgreSQL 9.3.1 中文手册 上一页 上一级 下一页ALTER TABLE 名称ALTER TABLE -- 修改表的定义 大纲 ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] RENAME [ COLUMN ] column_name TO new_column_name ALTER TABLE [ ...
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] RENAME [ COLUMN ] column_name TO new_column_name ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] RENAME CONSTRAINT constraint_name TO new_constraint_name ALTER TA...
PostgreSQL中对应的语法在alter table中,因为触发器与表相关,这样设计语法也符合逻辑的。 https://www.postgresql.org/docs/devel/static/sql-altertable.html ALTERTABLE[ IFEXISTS] [ONLY] name [*] action [, ... ] DISABLETRIGGER[ trigger_name|ALL|USER] ...
PostgreSQL 9.3.1 中文手册 上一页 上一级 下一页ALTER TABLE 名称ALTER TABLE -- 修改表的定义 大纲 ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ] RENAME [ COLUMN ] column_name TO new_column_name ALTER TABLE [ ...
PostgreSQL ALTER TABLE examples Let’s create a new table called links for practicing with the ALTER TABLE statement. DROP TABLE IF EXISTS links; CREATE TABLE links ( link_id serial PRIMARY KEY, title VARCHAR (512) NOT NULL, url VARCHAR (1024) NOT NULL ); To add a new column named acti...
在PostgreSQL中,ALTER TABLE命令用于修改现有表的结构。当对表进行大规模修改时,可能会导致ALTER TABLE执行变慢的情况。 Alter Table太慢可能由以下几个因素引起:...
ALTER TABLE [ IF EXISTS ] name RENAME TO new_name ALTER TABLE [ IF EXISTS ] name SET SCHEMA new_schema ALTER TABLE ALL IN TABLESPACE name [ OWNED BY role_name [, ... ] ] SET TABLESPACE new_tablespace [ NOWAIT ] ALTER TABLE [ IF EXISTS ] name ATTACH PARTITION partition_name { ...
Also note that the PostgreSQL syntax isnotsupported; thus, this willnotwork: ALTER TABLE IF EXISTS tab_name ... ; At this point, you are probably wondering: “But then, is this feature totally useless for me? Is there still no way to alter a table only if it exists?”. Hey, don’...