常用数据库查询判断表和字段是否存在
常用数据库查询判断表和字段是否存在
数据库postgresql表是否存在字段是否存在oracle
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';
总结:以上结果为1表示存在,为0表示不存在。