SQL Server : OR statement within CASE statement - sql

Question

I have a stored procedure that is querying some employee records based on what the user sends over.
On the UI, the user will enter multiple data points such as email addresses, User ID's, or Employee Names. This stored procedure checks what datatype they are providing and then searches that field in the database for the records.
Input to stored procedure:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<data>
<dataPoints>
<dataPoint>
<order>0</order>
<value>Jim Bob</value>
</dataPoint>
<dataPoint>
<order>1</order>
<value>Sally Jones</value>
</dataPoint>
</dataPoints>
</data>
</root>
Query:
#dataType VARCHAR (20), #data XML
AS
BEGIN
SET NOCOUNT ON;
BEGIN
-- Create a temp table
DECLARE #dataSet TABLE (data VARCHAR(100), [order] INT);
INSERT INTO #dataSet( data , [order] )
SELECT
ParamValues.x1.value('value[1]', 'VARCHAR(100)') ,
ParamValues.x1.value('order[1]', 'INT')
FROM
#data.nodes('/root/data/dataPoints/dataPoint') AS ParamValues(x1)
-- Search Employees
SELECT
ec.FirstName, ec.PreferredName, ec.LastName,
ec.NTID, ec.QID,
ec.DepartmentName, ec.SegmentName,
ec.CenterName, ec.RoleName, ec.MarketName,
ec.IncentivePlanName,
ec.CostCenterID,
ec.SupFirstName, ec.SupPreferredName, ec.SupLastName,
ec.SiloName,
ec.AreaName,
ec.PersonnelID,
d.[order]
FROM
Resources.emp.EmployeeComplete AS ec
INNER JOIN
#dataset AS d ON d.data = CASE
WHEN #dataType = 'NTID' THEN ec.ntid
WHEN #dataType = 'QID' THEN ec.QID
WHEN #dataType = 'Emp ID' THEN ec.EmpID
WHEN #dataType = 'Email Address' THEN ec.Email
WHEN #dataType = 'Personnel ID' OR #dataType = 'Sap ID' THEN ec.PersonnelID
--WHEN #dataType = 'Name' THEN (
-- (ec.FirstName + ' ' + ec.LastName)
-- OR (ec.PreferredName + ' ' + ec.LastName)
-- OR (ec.LastName + ', ' + ec.FirstName)
-- OR (ec.LastName + ', ' + ec.PreferredName
-- )
END
FOR XML PATH ('employees'), ELEMENTS, TYPE, ROOT ('root');
In short, I take the multiple data points being searched and throw them into an XML string to pass to the stored procedure. Once they arrive, I put them into a temp table so that I can join that with my main employee records.
The problem / question:
You will see I have some commented out code in my example and this is where my issue is. There are three name fields in my database. First Name, Preferred Name, Last Name.
I essentially need to test what the user provided and find employees based on the combination they entered them. All the user selects in the UI is that they are providing a name but not the format that its in.
For this reason, I need to check to see if I can find records in a couple of different formats.
Issue in this case is that I can't join my dataset using OR conditions in the CASE statement.
If #dataType = 'Name', I need to be able to join my temp table on a couple of the different combination possibilities.
The one thing we do make them aware of is that they can't mix and match. Meaning they cant do a FirstName LastName with a LastName FirstName search.
I had trouble explaining this so please let me know if I need to somehow clarify.

Answer 1

Push the equations in the CASE. If they are true let the THEN return 1. Check if the CASE returned 1. If and only if it did, you've found a match. In the conditions of WHEN you can use Boolean operators. So you can build your OR (or use IN as i did below) there.
...
CASE
WHEN #dataType = 'NTID' AND d.data = ec.ntid THEN 1
WHEN #dataType = 'QID' AND d.data = ec.QID THEN 1
...
WHEN (#dataType = 'Personnel ID' OR #dataType = 'Sap ID') AND d.data = ec.PersonnelID THEN 1
WHEN #dataType = 'Name' AND (d.data IN ('' + ec.FirstName + ' ' + ec.LastName,
'' + ec.PreferredName + ' ' + ec.LastName,
'' + ec.LastName + ', ' + ec.FirstName,
'' + ec.LastName + ', ' + ec.PreferredName) THEN 1
END = 1
...

Answer 2

What about just putting ORs in your join?
FROM #dataset AS d
INNER JOIN Resources.emp.EmployeeComplete AS ec
ON (#dataType = 'NTID' AND ec.ntid = d.data)
OR (#dataType = 'QID' AND ec.QID = d.data)
OR (#dataType = 'Emp ID' AND ec.EmpID = d.data)
OR (#dataType = 'Email Address' AND ec.Email = d.data)
OR ((#dataType = 'Personnel ID' OR #dataType = 'Sap ID') AND ec.PersonnelID = d.data)
OR (#dataType = 'Name' AND (ec.FirstName + ' ' + ec.LastName) = d.data)
OR (#dataType = 'Name' AND (ec.PreferredName + ' ' + ec.LastName) = d.data)
OR (#dataType = 'Name' AND (ec.LastName + ', ' + ec.FirstName) = d.data)
OR (#dataType = 'Name' AND (ec.LastName + ', ' + ec.PreferredName) = d.data)
I'm not sure if SQL is smart enough to use the proper indexes on those fields if you have them, probably especially not when combining columns. You would create indexed views for those combined names, or computed columns you could index on. It may be better to spread them out into separate queries in if/thens so SQL could optimize each query based on the field you are joining on and just execute the one query.