I猜你对这个专栏有限制。看看这里的讨论：



http://***.com/questions/9866989/alter-table-on-dependant-column [ ^ ]



http://social.msdn.microsoft.com/Forums/sqlserver/en-US / 9ca4e7b6-7ae8-4bf2-963e-23cc935b4b9c / modify-column-datatype-length [ ^ ]

I guess you have constraints on this column. Look at the discussion here:

http://***.com/questions/9866989/alter-table-on-dependant-column[^]

http://social.msdn.microsoft.com/Forums/sqlserver/en-US/9ca4e7b6-7ae8-4bf2-963e-23cc935b4b9c/modify-column-datatype-length[^]

为此您需要删除已实现的表约束优先。喜欢



ALTER TABLE table2

DROP CONSTRAINT FK_table2_table1;

ALTER TABLE table1

DROP CONSTRAINT PK_table1;



ALTER TABLE table1

ALTER COLUMN column1 nvarchar（32）NOT NULL;

ALTER TABLE table2

ALTER COLUMN column1 nvarchar（32）;



ALTER TABLE table1

ADD CONSTRAINT PK_table1

PRIMARY KEY（column1，column2）



ALTER TABLE table2

ADD CONSTRAINT FK_table1_table2

FOREIGN KEY（column1，column2）

REFERENCES table1（column1，column2）

For that you need to remove realted Table Constrain First. Like

ALTER TABLE table2
DROP CONSTRAINT FK_table2_table1;
ALTER TABLE table1
DROP CONSTRAINT PK_table1;

ALTER TABLE table1
ALTER COLUMN column1 nvarchar(32) NOT NULL;
ALTER TABLE table2
ALTER COLUMN column1 nvarchar(32);

ALTER TABLE table1
ADD CONSTRAINT PK_table1
PRIMARY KEY (column1, column2)

ALTER TABLE table2
ADD CONSTRAINT FK_table1_table2
FOREIGN KEY (column1, column2)
REFERENCES table1(column1, column2)