ALTERTABLEtable_name RENAMECOLUMNold_column_nameTOnew_column_name; 示例: 将middle_name列重命名为second_name: ALTERTABLEemployees RENAMECOLUMNmiddle_nameTOsecond_name; 6. 添加和删除约束 6.1 添加约束 要向表中添加约束,可以使用以下语法: ALTERTABLEtable_nameADDCONSTRAINTconstraint_name constraint_definition...
Postgres on Neon comes with a data admin UI. Get the free plan here. Summary: in this tutorial, you will learn how to use the PostgreSQL ALTER TABLE statement to modify the structure of a table. Introduction to PostgreSQL ALTER TABLE statement To change the structure of an existing table,...
ALTER TABLE table_name RENAME COLUMN column_name(修改表中的列名称) ALTERTABLEmovies.movies_aliyundrive-- RENAME COLUMN "仅供学习参考使用,下载后请于24小时内删除.不" TO "分类",-- RENAME COLUMN f2 TO "名称",RENAMECOLUMNf3TO"链接";
@文心快码postgres alter table alter column 文心快码 在PostgreSQL中,ALTER TABLE和ALTER COLUMN是用于修改表结构的关键命令。以下是针对你的问题的详细回答: 解释ALTER TABLE和ALTER COLUMN在PostgreSQL中的用途: ALTER TABLE:用于修改已存在的表结构,比如添加、删除或修改列,更改表的约束条件等。 ALTER COLUMN:是...
ALTER TABLE [ ONLY ] name [ * ] RENAME [ COLUMN ] column TO new_column ALTER TABLE name RENAME TO new_name ALTER TABLE name SET SCHEMA new_schema 这里action 是下列之一: ADD [ COLUMN ] column type [ column_constraint [ ... ] ] ...
Example 8: Renaming a Table To rename a specific table in Postgres, users need to use the “ALTER TABLE” command with the “RENAME TO” clause: ALTER TABLE emp_data RENAME TO emp_info; The above-specified statement will rename the “emp_data” table to “emp_info”: ...
How to Rename a Column in Postgres? A table column inPostgreSQLcan be renamed/modified using the"ALTER TABLE"command: ALTER TABLE tbl_name RENAME old_col_name TO new_col_name; - Here,ALTER TABLEis a command used to alter a table inPostgreSQL. ...
(12,2) | | | js | json | | | postgres=# alter table md2 rename column i to z; ALTER TABLE Time: 53.794 ms postgres=# \d+ md2 Table "public.md2" Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description ---+---+---+---+---+...
ALTER TABLE distributors RENAME COLUMN address TO city; 1. 对现存表改名: ALTER TABLE distributors RENAME TO suppliers; 1. 兼容性 SQL92 ADD COLUMN形式是兼容的,除了上面说的缺省(值)和约束外。ALTER COLUMN形式是完全兼容的。 SQL92 对ALTER TABLE声明了一些附加的Postgres目前还不支持的功能: ...
SQL92 对ALTERTABLE声明了一些附加的Postgres目前还不直接支持的功能: ALTERTABLEtableDROPCONSTRAINTconstraint{RESTRICT|CASCADE} 增加或删除表的约束(比如象检查约束,唯一约束或外键约束)。要创建或删除一个唯一约束,对应地创建或删除一个唯一索引,要修改其他类型的约束,你需要重建和重载该表,使用CREATETABLE命令的其他参数...