String queryString = " from TProject where nvl(submit,'no') <> 'yes'

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SQL code

String queryString = " from TProject where nvl(submit,'no') = 'no' ";

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from TProject where nvl(submit,'no') = 'no'  

就是 
select * from TProject  where submit is null;

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探讨


from TProject where nvl(submit,'no') = 'no' 

就是  
select * from TProject  where submit is null;


------解决方案--------------------
测试数据：
SQL code

CREATE TABLE TProject
(
    ID NUMBER(4),
    sub VARCHAR2(20)    
);
INSERT INTO TProject VALUES(1, 'yes');
INSERT INTO TProject VALUES(2, 'no');
INSERT INTO TProject VALUES(3, NULL);