LIKE and NULL in WHERE clause in SQL

Question

I have a store procedure which i have planned to use for search and get all values.

Scenario: If the parameter passed is NULL it should

Answer 1

You just need to add SET @Keyword = coalesce(@Keyword,'') to your procedure like this :

 ALTER procedure [dbo].[usp_GetAllCustomerDetails]
(
@Keyword nvarchar(20) =  null
)
As
Begin
SET @Keyword = coalesce(@Keyword,'')

Select CustomerId,CustomerName,CustomerTypeName,CustomerCode,CategoryName,CustomerMobile,CustomerEmail,CustomerAddress,CustomerCity,CustomerState,Pincode
from tblCustomerMaster CM
inner join dbo.tblCustomerTypeMaster CTM on CTM.CustomerTypeId = CM.CustomerType
inner join dbo.tblCategoryMaster CCM on CCM.CategoryId= CM.CustomerCategory
where CustomerName like '%'+@Keyword+'%' 

Answer 2

You can use condition like this in you where clause

where @Keyword is null or CustomerName like '%' + @Keyword + '%' 

Answer 3

I just want to point out another way of solving this problem. The issue is that the default value for @KeyWord is NULL. If you change the default to '', then the problem goes away:

ALTER procedure [dbo].[usp_GetAllCustomerDetails]
(
@Keyword nvarchar(20) = ''
)

Any non-NULL customer name would then be like '%%'.