関連ワード:  is null or empty in sql server    is null or empty check in sql server    check variable is null or empty in sql server    check value is null or empty in sql server    check string is null or empty in sql server    check if column is null or empty in sql server    string is null or empty sql server    is not null or empty sql server    check string is not null or empty in sql server    how to check datetime is null or empty in sql server