SQL find missing language entries in table - sql

Question

I have a table which is missing some entries for a certain language. How can I get a list of all language text in english (lang 1 in table) which is missing the foreign translation counterpart (lang 2)
My table is as follows
PageName | LanguageNo | TranslationName | TranslationText |
main | 1 | SomeName | some english text |
main | 2 | SomeName | some foreign text |
main | 1 | SomeName2 | some english 2 |
other | 1 | SomeName3 | some english 3 |
other | 2 | SomeName3 | some foreign 3 |
For example, using the above table data, only the following should be returned:
main | 1 | SomeName2 | some english 2 |
How can I write a SQL statement to achieve this?
Thanks

Answer 1

You can try the following:
-- Create demo data
CREATE TABLE #translation(pageName nvarchar(10), LanguageNo int, TranslationName nvarchar(25), TranslationText nvarchar(50))
INSERT INTO #translation(pageName, LanguageNo, TranslationName, TranslationText)
VALUES ('main',1,'SomeName','some english text'),
('main',2,'SomeName','some foreign text'),
('main',1,'SomeName2','some english 2'),
('other',1,'SomeName3','some english 3'),
('other',2,'SomeName3','some foreign 3')
--,('other',3,'SomeName3','some foreign 3') -- uncomment for language3 demo
-- your work:
SELECT availTrans.*
FROM #translation t
-- get all needed combinations
RIGHT JOIN(
SELECT DISTINCT t.pageName, t.TranslationName, langs.LanguageNo
FROM #translation as t
CROSS JOIN (SELECT DISTINCT LanguageNo FROM #translation) as langs
) as availTrans
ON t.pageName = availTrans.pageName
AND t.TranslationName = availTrans.TranslationName
AND t.LanguageNo = availTrans.LanguageNo
WHERE t.pageName IS NULL
-- Cleanup
DROP TABLE #translation
Given input:
pageName LanguageNo TranslationName TranslationText
---------- ----------- ------------------------- ---------------------
main 1 SomeName some english text
main 2 SomeName some foreign text
main 1 SomeName2 some english 2
other 1 SomeName3 some english 3
other 2 SomeName3 some foreign 3
Which produces this result:
pageName TranslationName LanguageNo
---------- ------------------------- -----------
main SomeName2 2

Answer 2

There are several methods, but here is one that uses not exists:
select t.*
from mytable t
where t.LanguageNo = 1 and
not exists (select 1
from mytable t2
where t2.pagename = t.pagename and
t2.translationname = t.translationname and
t2.LanguageNo = 2
);
Here is a SQL Fiddle.

Answer 3

You can also use SUM with OVER() like this.
Query
;WITH CTE AS
(
SELECT pageName, LanguageNo, TranslationName, TranslationText,
SUM(CASE WHEN LanguageNo = 1 THEN 1 ELSE 0 END) OVER(PARTITION BY TranslationName) L1,
SUM(CASE WHEN LanguageNo = 2 THEN 1 ELSE 0 END) OVER(PARTITION BY TranslationName) L2
FROM #translation t
)
SELECT pageName, LanguageNo, TranslationName, TranslationText FROM CTE
WHERE L1 >=1 AND L2 = 0
Output
pageName LanguageNo TranslationName TranslationText
main 1 SomeName2 some english 2

Answer 4

SELECT t1.*
FROM tblTranslation t1
LEFT JOIN tblTranslation t2
ON t2.TranslationName = t1.TranslationName
AND t2.LanguageNo = 2
WHERE t2.TranslationName IS NULL
AND t1.LanguageNo = 1

Answer 5

SELECT t1.*
FROM tblTranslation t1
LEFT JOIN tblTranslation t2 ON t2.PageName = t1.PageName
AND t2.TranslationName = t1.TranslationName
AND t2.LanguageNo = 2
WHERE t1.LanguageNo = 1
AND t2.LanguageNo IS NULL