関連ワード:  sql server change column type    sql server change column type without losing data    sql server change column type with default value    sql server change column type from int to varchar    sql server change column type without dropping table    sql server change column type from varchar to nvarchar    sql server change column type from int to bigint    sql server change column type from datetime to datetime2    sql server change column type from int to decimal    sql server change column type not null