欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  数据库

常用数据库查询判断表和字段是否存在的SQL

程序员文章站 2022-04-09 19:29:53
...
常用数据库查询判断表和字段是否存在的SQL(如果结果为1表示存在,为0表示不存在)

1、MSSQL Server
表:

SELECT COUNT(*) FROM dbo.sysobjects 
WHERE name= 'table_name';

字段:

SELECT COUNT(*) FROM syscolumns 
WHERE id=object_id(‘table_name’) AND name= 'column_name';


2、My SQL
表:

SELECT COUNT(*) FROM information_schema.tables 
WHERE table_name ='table_name';

字段:

SELECT COUNT(*) FROM information_schema.columns 
WHERE table_name ='table_name' AND column_name ='column_name';


3、Oracle
表:

SELECT count(*) FROM USER_OBJECTS 
WHERE OBJECT_NAME = 'table_name';

字段:

SELECT COUNT(*) FROM USER_TAB_COLUMNS 
WHERE TABLE_NAME ='table_name' AND column_name ='column_name';


4、PostgreSql
表:

SELECT count(*) FROM information_schema.tables 
WHERE table_schema='table_schema' AND table_name ='table_name';

字段:

SELECT count(*) FROM information_schema.columns 
WHERE table_schema='table_schema' AND table_name ='table_name' AND column_name='column_name';