Pass comparison operators as parameters and use directly in SQL stored procedure - sql

Question

I have a SQL stored procedure which takes several parameters. In there I need to pass conditions as =, <, > and use them in the query.
Currently what I'm doing is I check what's the condition and change a part of the query according to it. I want to pass the condition as a parameter and use it directly in the query.
This is how I'm doing now,
I'm passing these parameters:
#software_type nvarchar(50),
#software_id nvarchar(50),
#condition char,
#version_id float
Query:
DECLARE
#BaseQuery nvarchar(max) = N'SELECT DISTINCT Installed_Software.vm_name FROM Installed_Software INNER JOIN Software ON Installed_Software.software_id = Software.software_id INNER JOIN Software_Version ON Installed_Software.software_id = Software_Version.software_id AND Installed_Software.version_id = Software_Version.version_id AND Software.software_id = Software_Version.software_id',
#WhereClause nvarchar(max) = ' WHERE 1=1',
#ParamList nvarchar(max) = N'#sfType nvarchar(50),#sfId nvarchar(50),#verId float,#cond char'
IF #software_type IS NOT NULL
BEGIN
SET #WhereClause = #WhereClause + ' AND Software.software_type = #sfType';
END
IF #software_id IS NOT NULL
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.software_id=#sfId';
END
IF #version_id IS NOT NULL AND #condition IS NOT NULL
BEGIN
IF #condition = '='
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id = #verId';
END
ELSE IF #condition ='>'
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id > #verId';
END
ELSE IF #condition='<'
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id < #verId';
END
ELSE IF #condition = '>='
BEGIN
SET #WhereClause=#WhereClause + ' AND Installed_Software.version_id >= #verId';
END
ELSE IF #condition='<='
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id <= #verId';
END
ELSE
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id = #verId';
END
END
SET #BaseQuery = #BaseQuery + #WhereClause;
EXECUTE sp_executesql #BaseQuery, #ParamList, #sfType=#software_type, #sfId=#software_id, #verId=#version_id;
What I want to do is something like this:
IF #version_id IS NOT NULL AND #condition IS NOT NULL
BEGIN
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id' + '#condition' + '#version_id';
END
Is this possible to do that?

Answer 1

I would suggest not using dynamic sql for this.
I believe that the following query should return the same results as the dynamic sql version:
SELECT DISTINCT Installed_Software.vm_name
FROM Installed_Software
INNER JOIN Software
ON Installed_Software.software_id = Software.software_id
INNER JOIN Software_Version
ON Installed_Software.software_id = Software_Version.software_id
AND Installed_Software.version_id = Software_Version.version_id
AND Software.software_id = Software_Version.software_id
WHERE
(
#software_type IS NULL
OR Software.software_type = #software_type
)
AND
(
#software_id IS NULL
OR Installed_Software.software_id = #software_id
)
AND
(
#version_id IS NULL
OR #condition IS NULL
OR (#condition = '=' AND Installed_Software.version_id = #version_id)
OR (#condition = '>' AND Installed_Software.version_id > #version_id)
OR (#condition = '<' AND Installed_Software.version_id < #version_id)
OR (#condition = '>=' AND Installed_Software.version_id >= #version_id)
OR (#condition = '<=' AND Installed_Software.version_id <= #version_id)
)

Answer 2

Is this possible to do that? YES
Just add single space between your condition to avoid syntactical error
SET #WhereClause = #WhereClause + ' AND Installed_Software.version_id ' + '#condition' + ' #version_id';
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