如何在SQL Server 2008中将所有varchar数据类型列更改为Nvarchar数据类型列

Question

I have a list of tables where i have to change VARCHAR datatype of all columns no NVARCHAR datatype.

While changing to NVARCHAR i should get all those not null and null columns. It should change the size of columns having >4000 to NVARCHAR(MAX) and want to change the size of primary key columns to 448 when converted to NVARCHAR.The primary key columns cause problem while converted to NVARCHAR when the size is above 448 due to index errors

Answer 1

This query will give you a list of all varchar columns with length and nullability

SELECT TABLE_CATALOG,
       TABLE_SCHEMA,
       TABLE_NAME,
       COLUMN_NAME,
       CHARACTER_OCTET_LENGTH,
       IS_NULLABLE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE DATA_TYPE='varchar'

Your question is unclear, for me to help more.

While changing to NVARCHAR i should get all those not null and null columns

Does this mean you want to retain nullability property as is? Please ask with more clarity.