CREATE TABLE TEST (NAME TEXT, LANG INT(2));

INSERT INTO TEST (NAME, LANG) VALUES ('US',1);
INSERT INTO TEST (NAME, LANG) VALUES ('US',2);
INSERT INTO TEST (NAME, LANG) VALUES ('EU',2);

SELECT * FROM TEST WHERE CASE
WHEN LANG=1 THEN LANG=1
ELSE LANG=2
END

US 1
US 2
EU 2

US 1
EU 2