DROP ROLE [ IF EXISTS ] _name_ [, ...] DROP RULE 删除一个重写规则。 DROP RULE name ON relation [ CASCADE | RESTRICT ] DROP SCHEMA 删除一个模式。 DROP SCHEMA name [, ...] [ CASCADE | RESTRICT ] DROP SEQUENCE 删除一个序列。 DROP SEQUENCE name [, ...] [ CASCADE | RESTRICT ] ...
First, drop the sample tables and re-create them with the foreign key that uses the SET NULL action in the ON DELETE clause: DROP TABLE IF EXISTS contacts; DROP TABLE IF EXISTS customers; CREATE TABLE customers( customer_id INT GENERATED ALWAYS AS IDENTITY, customer_name VARCHAR(255) NOT ...
postgres=# \help drop database; Command: DROP DATABASE Description: remove a database Syntax: DROP DATABASE [ IF EXISTS ] name [ [ WITH ] ( option [, ...] ) ] where option can be: FORCE URL: https://www.postgresql.org/docs/14/sql-dropdatabase.html postgres=# drop database bbc...
CREATE TABLE orders ( order_id integer PRIMARY KEY, product_no integer REFERENCES products, quantity integer ); # 定义多个 Column 组成的外键,要求被约束列(外键)的数量和类型应该匹配被引用列(主键)的数量和类型。 CREATE TABLE t1 ( a integer PRIMARY KEY, b integer, c integer, FOREIGN KEY (b, ...
DROP ROLE [ IF EXISTS ] _name_ [, ...]DROP RULE删除一个重写规则。DROP RULE name ON relation [ CASCADE | RESTRICT ]DROP SCHEMA删除一个模式。DROP SCHEMA name [, ...] [ CASCADE | RESTRICT ]DROP SEQUENCE删除一个序列。DROP SEQUENCE name [, ...] [ CASCADE | RESTRICT ]...
DROP OPERATOR CLASS name USING index_method [ CASCADE | RESTRICT ] 1. DROP ROLE 删除一个数据库角色。 DROP ROLE [ IF EXISTS ] _name_ [, ...] 1. DROP RULE 删除一个重写规则。 DROP RULE name ON relation [ CASCADE | RESTRICT ]
create_missing : true - 如果不存在对应的key值,则新增,反之,false - 不做其他操作,这里可有可无 数据准备 加入现在有一张表含有如下字段:id, action_params, bindings三个字段; AI检测代码解析 CREATE TABLE IF NOT EXISTS t_trigger ( id int8 not null, ...
drop database test; 数据库在修改数据库名称、删除的时候,以下状态无法操作成功。当数据库处于正在使用状态等的时候。 修改数据库连接最大值 alter database testdb with connection limit=1000; 在创建数据库时,create database后面不能直接加条件,需要配合alter语句进行。这和SQL server有差别。
CREATE TABLE IF NOT EXISTS skills( Id serial, Userid integer NOT NULL, Name VARCHAR(10) NOT NULL, CreatedAt timestamptz DEFAULT current_timestamp, UpdatedAt timestamptz DEFAULT current_timestamp, CONSTRAINT skills_pkey PRIMARY KEY(Id), CONSTRAINT skills_Userid_fkey FOREIGN KEY(Userid) ...
postgres--drop table if exists mytest.emp ;CREATE TABLE if not exists mytest.emp (empno numeric NOT NULL,ename character varying(10),job character varying(9),mgr numeric,hiredate date,sal numeric(7,2),comm numeric(7,2),deptno numeric(2,0));ALTER TABLE mytest.emp OWNER TO postgres;-...