If Else Statement in SQL Server stored procedure - sql

Question

In SQL Server, on .NET you can add together a SQL statement and therefor use either 'or' or 'and'.
I am stuck how to do this in a SQL Server stored procedure.
Question:
What is it called what you add together SQL statements? I have a feeling it starts with a 'c' concocations??
I believe I am close with the below code to having a 'variable' SQL?
Code:
BEGIN
SELECT *
FROM TblEmployee
WHERE
FirstName LIKE '%' + LTRIM(RTRIM((#sFirstName))) + '%'
or
Surname LIKE '%' + LTRIM(RTRIM((#sSurname ))) + '%'
and
IF (LTRIM(RTRIM((#sOfficeBase))) = 'xyz1234')
and OfficeBase = LTRIM(RTRIM((#sOfficeBase)))
ELSE
or
OfficeBase= LTRIM(RTRIM((#sOfficeBase)))
END
There are simular queries such as If else in stored procedure sql server
But I have a feeling I searching for the 'wrong' question. Thanks in advance

Answer 1

The where clause allows you to embed conditional logic - you don't need if/then/else, which is just as well, because afaik, that's not supported by any SQL dialect in a where clause.
BEGIN
SELECT *
FROM TblEmployee
WHERE
FirstName LIKE '%' + LTRIM(RTRIM((#sFirstName))) + '%'
or
Surname LIKE '%' + LTRIM(RTRIM((#sSurname ))) + '%'
and
(OfficeBase = 'xyz1234'
or
OfficeBase= LTRIM(RTRIM((#sOfficeBase)))
END

Answer 2

I am pretty sure you have some missing parenthesis in your original query. Not sure why you are adding LTRIM and RTRIM to your parameters. Taking a shot in the dark I suspect you could boil down your query to this.
SELECT * --This should be the column names actually needed, * is not good for production code
FROM TblEmployee
WHERE
(
FirstName LIKE '%' + #sFirstName + '%'
or
Surname LIKE '%' + #sSurname + '%'
)
and OfficeBase in ('xyz1234', #sOfficeBase)