T-SQL Select row only if not exist already - sql

Question

I have a table with two Ids, ResourceId and LanguageId
I need to join those two selects where second result would be added only if ResourceId not already in the list.
SELECT * FROM Resources WHERE Language = 1
SELECT * FROM Resources WHERE Language = 0
JOIN
/*where ResourceId not present already*/
So far I came up with nothing except complicated partitions. Is there better solution to this?
Not all ResourceIds have Language 0 entry
Not all ResourceIds have Language 1 entry
Some ResourceIds have both
CREATE TABLE [dbo].[Resources](
[Id] [bigint] NOT NULL,
[ResourceId] [bigint] NOT NULL,
[LanguageId] [int] NOT NULL,
[Text] [nvarchar](2000) NULL,
[Path] [varchar](2000) NULL,
CONSTRAINT [PK_Resourcces] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

Answer 1

You could use a union with exists logic:
SELECT * FROM Resources WHERE Language = 1
UNION ALL
SELECT *
FROM Resources r1
WHERE
Language = 0 AND
NOT EXISTS (SELECT 1 FROM Resources r2
WHERE r2.Language = 1 AND r2.ResourceId = r1.ResourceId);

Answer 2

You can number the rows per resourceid by languageid using the row_number() window function and then just select the "first" one.
SELECT id,
resourceid,
languageid,
text,
path
FROM (SELECT id,
resourceid,
languageid,
text,
path,
row_number() OVER (PARTITION BY resourceid
ORDER BY languageid DESC) rn
FROM resources
WHERE languageid IN (0,
1) x
WHERE rn = 1;

Answer 3

Since I had started answering but Tim was more effective than me, I still put my answer as you indicated that, and I quote:
If somebody finds something faster and simpler, I would love to see it
USE TEST
CREATE DATABSE TEST
CREATE TABLE Ressources
(
RessourceId INT,
LanguageId INT
);
INSERT INTO Ressources
VALUES
(1,1),
(1,0),
(1,2),
(1,3),
(2,1),
(2,0),
(2,2),
(3,1),
(4,1),
(5,0)
WITH CTE_L1 AS (SELECT * FROM Ressources WHERE LanguageId = 1)
SELECT * FROM CTE_L1
UNION ALL
SELECT * FROM Ressources
WHERE LanguageId = 0
AND RessourceId NOT IN(SELECT RessourceId FROM CTE_L1)
Results I got:
RessourceId LanguageId
----------- -----------
1 1
2 1
3 1
4 1
5 0
(Same result if I execute the #Tim Biegeleisen query)
See which one you like best.
--> Cost of mine query 0.010132
--> Cost of Tim query 0.0100952
(Based on the execution plan)