Incorrect parameter count in the call to native function 'ISNULL'

Question

I have a query that I am trying to convert to MySQL from MS SQL Server 2008. It runs fine on MSSQL, I get the error "Incorrect parameter count in the call to native function 'ISNULL'".

How do I solve this?

SELECT DISTINCT
    dbo.`@EIM_PROCESS_DATA`.U_Tax_year,
    dbo.`@EIM_PROCESS_DATA`.U_Employee_ID,
    CASE
        WHEN dbo.`@EIM_PROCESS_DATA`.U_PD_code = 'SYS033' THEN SUM(dbo.`@EIM_PROCESS_DATA`.U_Amount)
    END AS PAYE,
    CASE
        WHEN dbo.`@EIM_PROCESS_DATA`.U_PD_code = 'SYS014' THEN SUM(dbo.`@EIM_PROCESS_DATA`.U_Amount)
    END AS TOTALTAXABLE,
    dbo.OADM.CompnyName,
    dbo.OADM.CompnyAddr,
    dbo.OADM.TaxIdNum,
    dbo.OHEM.lastName + ', ' + ISNULL(dbo.OHEM.middleName, '') + '' + ISNULL(dbo.OHEM.firstName, '') AS EmployeeName
FROM
    dbo.`@EIM_PROCESS_DATA`
        INNER JOIN
    dbo.OHEM ON dbo.`@EIM_PROCESS_DATA`.U_Employee_ID = dbo.OHEM.empID
        CROSS JOIN
    dbo.OADM
GROUP BY dbo.`@EIM_PROCESS_DATA`.U_Tax_year , dbo.`@EIM_PROCESS_DATA`.U_Employee_ID , dbo.OADM.CompnyName , dbo.OADM.CompnyAddr , dbo.OADM.TaxIdNum , dbo.OHEM.lastName , dbo.OHEM.firstName , dbo.OHEM.middleName , dbo.`@EIM_PROCESS_DATA`.U_PD_code

MySQL

SELECT DISTINCT 
     processdata.taxYear, processdata.empID, 
     CASE WHEN processdata.edCode = 'SYS033' THEN SUM (processdata.amount) END AS PAYE, 
     CASE WHEN processdata.edCode = 'SYS014' THEN SUM (processdata.amount) END AS TOTALTAXABLE, 
     company.companyName, company.streetAddress, company.companyPIN, employeemaster.lastName + ', ' + IFNULL(employeemaster.middleName, '') 
     + ' ' + IFNULL(employeemaster.firstName, '') AS EmployeeName
FROM         
     processdata INNER JOIN
     employeemaster ON processdata.empID = employeemaster.empID 
     CROSS JOIN company
     GROUP BY processdata.taxYear, processdata.empID, company.companyName, company.streetAddress, company.companyPIN, 
     employeemaster.lastName, employeemaster.firstName, employeemaster.middleName, processdata.edCode

Answer 1

The MySQL equivalent of ISNULL is IFNULL

If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2.

Maybe also look at SQL NULL Functions

The ISNULL from MySQL is used to check if a value is null

If expr is NULL, ISNULL() returns 1, otherwise it returns 0.

Answer 2

I would suggest that you switch to the ANSI standard function coalesce():

(dbo.OHEM.lastName + ', ' + coalesce(dbo.OHEM.middleName, '') + '' + coalesce(dbo.OHEM.firstName, '')
) AS EmployeeName

You could also make your query easier to read by including table aliases.

EDIT:

As a note, I seemed to have missed the direction of conversion. The MySQL query would use concat():

CONCAT(OHEM.lastName, ', ', coalesce(OHEM.middleName, ''),
       coalesce(concat(' ', OHEM.firstName), '')
      ) AS EmployeeName