Question

I have two tables that have relationship with UserName field. Based on UserName column, I want to get ID from CarReserve table. Here is my SQL statement:

SELECT CarReserve.ID 
FROM CarReserve 
 INNER JOIN aspnet_Users ON CarReserve.UserName = aspnet_Users.UserName 
WHERE UserName = @UserName

Unfortunately, I am getting this warning:

Ambiguous column name “UserName”

Can anyone here tell me what is wrong with my statement?

Answer 1

Add table name before UserName in WHERE UserName = @UserName

Your query should be:

SELECT CarReserve.ID 
    FROM CarReserve 
    INNER JOIN aspnet_Users ON CarReserve.UserName = aspnet_Users.UserName 
    WHERE aspnet_Users.UserName = @UserName
    ------^-----------^----------------

Or

SELECT CarReserve.ID 
    FROM CarReserve 
    INNER JOIN aspnet_Users ON CarReserve.UserName = aspnet_Users.UserName 
    WHERE CarReserve.UserName = @UserName
    ------^---------^----------------