I have this query:

declare @password nvarchar(254) ='R0nald0$123456.', 
@username nvarchar(50)='Ronaldo',
@playerId uniqueidentifier,
@userType int;

declare @UserUsername_CS int =CHECKSUM(@username);

    SELECT Top 1 @playerId = [UserId]
      FROM [dbo].[UsersPrivate]
     WHERE [UserUsername_CS] =  @UserUsername_CS    
       And [UserUsername]   = @username                
       AND [UserPassword]   = HASHBYTES('SHA2_256', CONCAT([Salt], @password));

select @playerId

It generates the right result; however, I am not sure I am using the “best way” to do this when comparing the user’s password with the provided password via the hash.

As [Salt] is part of the table, I can’t pre-glue them to get a Binary(32) variable. I have the following index:

CREATE UNIQUE INDEX [IX_UsersPrivate_UserName_UserPassword] ON [dbo].[UsersPrivate]
(
    [UserUsername_CS] ASC,
    [UserUsername] ASC,
    [UserPassword] ASC  
)

, which is ignored by the execution plan.

Type conversion in expression (CONVERT_IMPLICIT(nvarchar(8),
[ClubStat].[dbo].[UsersPrivate].[Salt],0)) may affect
“CardinalityEstimate” in query plan choice

Here is the execution plan: Past the plan