1.1创建表 1.2 查看表 1.3清空表数据 1.4删除表 1.5退出数据库 2.表属性操作 2.1增加列 2.2删除列 2.3修改列属性 2.4增加列非空约束 2.5 增加列唯一约束 2.6删除主键约束 2.7创建主键约束 2.8 删除外键约束 2.9 增加外键约束 2.10 修改表名 3.表数据操作 3.1数据查询 3.2数据条件查询【where】 3.3数据表达式查询...
In Postgres Delete Cascade, we will learn how to manage database CRUD operation delete in case of a relational database that contains multiple tables with foreign key constraints between them. When deleting records from a table in PostgreSQL, it is crucial to consider whether it has any foreign...
ON DELETE CASCADE, ,--创建外键 OrderDate datetime default(getdate()), name nvarchar(20) not null )---下面一一介绍。外键ON后面可以跟4个参数。SET NULL,SET DEFAULT,NOT ACTION ,CASCADE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. NOT ACTION:执行删除和更新操作时候会总拒绝执行,因为子集数据无法得...
CARDINALITY保留非保留 CASCADE非保留非保留保留保留 CASCADED保留保留保留 CASE保留保留保留保留 CAST保留保留保留保留 CATALOG非保留保留保留 CATALOG_NAME非保留非保留非保留 CEIL保留 CEILING保留 CHAIN非保留非保留非保留 CHAR非保留(不能是函数或类型)保留保留保留 CHARACTER非保留(不能是函数或类型)保留保留保留 CHARACT...
delete from 表名; 10创建表 create table 字段名 类型; 角色创建: 1create role rolename with optional_permisson; 2create role rolename with login; \h create role 可查看创建角色时可设置的管理权限 3改变角色的权限“ alter role rolename with attribute_options; ...
CREATE TRIGGER t1t2_test_sync_delete AFTER DELETE ON t1_schema.t1 FOR EACH ROW EXECUTE PROCEDURE t1_schema.sync_trigger_delete() ; (B) 基于外键的解决方案 在t2 (col1,col2,col3)上使用t1 (col1, col2, col3)选项ON UPDATE CASCADE ON DELETE CASCADE引用t1 (col1, col2, col3)的外键可能...
GRANT SELECT, UPDATE, INSERT, DELETE ON TABLE public.user TO mydata_dml; GRANT SELECT ON TABLE public.user TO mydata_qry; 删除账号 #撤回在public模式下的权限 revoke select on all tables in schema public from 用户名; #撤回在information_schema模式下的权限 ...
SQL级联删除——删除主表同时删除从表——同时删除具有主外键关系的表 create table a ( id varchar(20) primary key, password varchar(20)...userId varchar(20), foreign key (userId) references a(id) on delete cascade ) 表B创建了外码userId 对应A的主码ID,声明了级联删除...values('23','aaa...
{}', "createdAt" TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, "updatedAt" TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, CONSTRAINT fk_smart_info_asset FOREIGN KEY ("assetId") REFERENCES assets(id) ON DELETE CASCADE ); -- Now create the index CREATE INDEX IF NOT EXISTS idx_...
postgreSQL数据库默认⽤户postgres常⽤命令分享 1、修改⽤户postgres的密码 #alter user postgres with password ‘xxxx';(其中xxxx是修改的密码)。2、查看下当前schema的所有者：// 查看当前schema的所有者，相当于\du元命令 SELECT n.nspname AS "Name",pg_catalog.pg_get_userbyid(n.nspowner) AS "...