Try to specify the alises all in one place. Save yourself some typing. Also build the full select starement. Also could be used as a create view statement. Interesting idea though.

INSERT INTO #ExpressionToDataTypeAndNull

( DATA_TYPE ,

IS_NULLABLE ,

CustomExpression

)

VALUES

( 'varchar','YES','LTRIM(RTRIM(ISNULL("<column>",'''')))')

,( 'varchar','NO','LTRIM(RTRIM("<column>"))"')

,( 'nvarchar','YES','LTRIM(RTRIM(ISNULL("<column>",'''')))')

,( 'nvarchar','NO','LTRIM(RTRIM("<column>"))')

,( 'datetime','YES','CAST("<column>" AS varchar(max))')

,( 'datetime','NO','CAST("<column>" AS varchar(max))')

;

DECLARE @TableName nvarchar(128)

SET @TableName = 'FictionalEmployees'

DECLARE @SqlSelect NVARCHAR(MAX)

SELECT @SqlSelect = COALESCE(

@SqlSelect + ', ' + ISNULL(REPLACE(CustomExpression,'<column>', COLUMN_NAME), COLUMN_NAME )

, ISNULL(REPLACE(CustomExpression,'<column>', COLUMN_NAME), COLUMN_NAME )

) + ' AS "' + COLUMN_NAME + '"'

FROM INFORMATION_SCHEMA.COLUMNS a

FULL OUTER JOIN #ExpressionToDataTypeAndNull b

ON a.DATA_TYPE = b.DATA_TYPE

AND a.IS_NULLABLE = b.IS_NULLABLE

WHERE TABLE_NAME = @TableName

ORDER BY ordinal_position ASC;

SET @SqlSelect = 'SELECT ' + @SqlSelect + 'FROM ' + @TableName

PRINT @SqlSelect

-- EXECUTE sp_executesql @SqlSelect