create table test ( oldfield1 int, oldfield2 int, oldfield3 int )insert into test select 1,2,3 union all select 1,2,3 union all select 1,2,3 goselect * from test goalter table test drop column oldfield2 select * from test goalter table test add newfield1 int select * from test godrop table test go
(
oldfield1 int,
oldfield2 int,
oldfield3 int
)insert into test
select 1,2,3
union all
select 1,2,3
union all
select 1,2,3
goselect * from test
goalter table test drop column oldfield2
select * from test
goalter table test add newfield1 int
select * from test
godrop table test
go
ALTER TABLE table
{ [ ALTER COLUMN column_name
{ new_data_type [ ( precision [ , scale ] ) ]
[ COLLATE < collation_name > ]
[ NULL | NOT NULL ]
| {ADD | DROP } ROWGUIDCOL }
]
| ADD
{ [ < column_definition > ]
| column_name AS computed_column_expression
} [ ,...n ]
| [ WITH CHECK | WITH NOCHECK ] ADD
{ < table_constraint > } [ ,...n ]
| DROP
{ [ CONSTRAINT ] constraint_name
| COLUMN column } [ ,...n ]
| { CHECK | NOCHECK } CONSTRAINT
{ ALL | constraint_name [ ,...n ] }
| { ENABLE | DISABLE } TRIGGER
{ ALL | trigger_name [ ,...n ] }
}< column_definition > ::=
{ column_name data_type }
[ [ DEFAULT constant_expression ] [ WITH VALUES ]
| [ IDENTITY [ ( seed , increment ) [ NOT FOR REPLICATION ] ] ]
]
[ ROWGUIDCOL ]
[ COLLATE < collation_name > ]
[ < column_constraint > ] [ ...n ]< column_constraint > ::=
[ CONSTRAINT constraint_name ]
{ [ NULL | NOT NULL ]
| [ { PRIMARY KEY | UNIQUE }
[ CLUSTERED | NONCLUSTERED ]
[ WITH FILLFACTOR = fillfactor ]
[ ON { filegroup | DEFAULT } ]
]
| [ [ FOREIGN KEY ]
REFERENCES ref_table [ ( ref_column ) ]
[ ON DELETE { CASCADE | NO ACTION } ]
[ ON UPDATE { CASCADE | NO ACTION } ]
[ NOT FOR REPLICATION ]
]
| CHECK [ NOT FOR REPLICATION ]
( logical_expression )
}< table_constraint > ::=
[ CONSTRAINT constraint_name ]
{ [ { PRIMARY KEY | UNIQUE }
[ CLUSTERED | NONCLUSTERED ]
{ ( column [ ,...n ] ) }
[ WITH FILLFACTOR = fillfactor ]
[ ON { filegroup | DEFAULT } ]
]
| FOREIGN KEY
[ ( column [ ,...n ] ) ]
REFERENCES ref_table [ ( ref_column [ ,...n ] ) ]
[ ON DELETE { CASCADE | NO ACTION } ]
[ ON UPDATE { CASCADE | NO ACTION } ]
[ NOT FOR REPLICATION ]
| DEFAULT constant_expression
[ FOR column ] [ WITH VALUES ]
| CHECK [ NOT FOR REPLICATION ]
( search_conditions )
}
ALTER TABLE TABLENAME
DROP
COLUMN COLUMNNAME添加新列
ALTER TABLE TABLENAME
ADD
COLUMNNAME TYPE设置默认值
CREATE DEFAULT NAMEDEFAULT AS 'DEFAULTVALUES'绑定
EXEC SP_BINDEFAULT
@DEFNAME = NAMEDEFAULT,
@OBJNAME = 'TABLENAME.[COLUMNNAME]'存储过程的修改我基本上在企业管理器上其实这些语句都在T-SQL帮助上有
也就是楼上的语句楼主要学会看这样的帮助的
呵呵