RTRIM(LTRIM(SD.Code ))<>''

FROM Table1 SD WITH (NOLOCK) JOIN Table2 WITH (NOLOCK) etc.

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

WHERE SD.Code IS NOT NULL AND RTRIM(LTRIM(SD.Code ))<>''

WHERE SD.Code <> ''

DECLARE @Table	table(
	mystring	char(15))

INSERT @Table 
VALUES( ''),( ' '),( '   '),
	( 'a'),( ' b'),( 'c '),
	( '                '), (NULL)

SELECT * FROM @Table
WHERE mystring <> ''

CREATE TABLE #Employee (ID INT IDENTITY(1, 1), Forename VARCHAR(20))

INSERT INTO #Employee(Forename)
SELECT 'Abu Dina' UNION ALL 
SELECT 'SQL4n00bs' UNION ALL 
SELECT 'Test' UNION ALL 
SELECT '1337'

CREATE TABLE #Location (ID INT IDENTITY(1, 1), Employee_ID INT, Location VARCHAR(50))

INSERT INTO #Location(Employee_ID, Location)
SELECT 1, 'UK' UNION ALL 
SELECT 2, 'Manchester'


SELECT a.* , b.*
FROM #Employee AS a
LEFT JOIN #Location AS b
	ON a.id = b.employee_id
	and a.forename = 'Abu Dina'
	
SELECT a.* , b.*
FROM #Employee as a
LEFT JOIN #Location as b
	ON a.id = b.employee_id
	WHERE a.forename = 'Abu Dina'
	
	DROP TABLE #Employeea
	DROP TABLE #Location

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

WHERE SD.Code IS NOT NULL AND RTRIM(LTRIM(SD.Code ))<>''

WHERE SD.Code > ''