摘要:
常用数据库定义语言DDL--1.判断表中是否存在某个字段select * from SysObjects a left join SysColumns b on a.id = b.id where a.name = 'TableName' and b.Name='ColumnName'--2.在表中新增一个字段alter table TableName add ColumnName varchar(100) default ('') with values--3.在表中删除一个字段alter table TableName drop column 阅读全文