How to use NULL or empty string in SQL

Question

I would like to know how to use NULL and an empty string at the same time in a WHERE clause in SQL Server. I need to find records that have either null values o

Answer 1

youe check null With IS NULL and string Empty With LEN(RTRIM(LTRIM(Column))) = 0 in

SELECT *
FROM AppInfra.Person
WHERE   LEN(RTRIM(LTRIM(NationalCode))) = 0 OR  NationalCode IS NULL

Answer 2

You can simply do this:

SELECT *
FROM   yourTable
WHERE  yourColumn IS NULL OR yourColumn = ''

Answer 3

SELECT *
FROM   TableName
WHERE  columnNAme IS NULL OR 
       LTRIM(RTRIM(columnName)) = ''

Answer 4

select 
   isnull(column,'') column, * 
from Table  
Where column = ''