--向表中增加一个 varchar 列: ALTER TABLE distributors ADD COLUMN address VARCHAR(30);
--对现存列改名: ALTER TABLE distributors RENAME COLUMN address TO city;--更改现存表的名字∶ ALTER TABLE distributors RENAME TO suppliers;--给一个表增加一个检查约束∶ ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5); --删除一个表和它的所有子表的监查约束∶ ALTER TABLE distributors DROP CONSTRAINT zipchk;
--向表中增加一个外键约束: ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses(address) MATCH FULL;--给表增加一个(多字段)唯一约束∶ ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);
alter table Sys_Employee change eProject, eProId int 是想改eProject字段名为eProId
alter table Sys_Employee COLUMN eProject TO eProId
exec sp_rename '表名.字段名','新列名'
提示在关键字 'column' 附近有语法错误。不对啊
alter table Sys_Employee rename column eProject, eProId
一样的嘛!
ALTER TABLE distributors ADD COLUMN address VARCHAR(30);
--对现存列改名:
ALTER TABLE distributors RENAME COLUMN address TO city;--更改现存表的名字∶
ALTER TABLE distributors RENAME TO suppliers;--给一个表增加一个检查约束∶
ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5); --删除一个表和它的所有子表的监查约束∶
ALTER TABLE distributors DROP CONSTRAINT zipchk;
--向表中增加一个外键约束:
ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses(address) MATCH FULL;--给表增加一个(多字段)唯一约束∶
ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);
是想改eProject字段名为eProId
exec sp_rename '表名.字段名','新列名'
Alter table tb Add eProId nvarchar(10)
'ePrject' 不是约束。
服务器: 消息 3727,级别 16,状态 1,行 1
未能除去约束。请参阅前面的错误信息。
alter table t change oldcol newcol type;
mssql:
sp_rename 't.oldcol','newcol','column';
or
dbcc renamecolumn(N't',N'oldcol',N'newcol')
alter table Sys_Employee alter column eProId int;