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select * from tt where f1 is null
select * from yourTable where col is null;
SQL code:
sqlite> create table Aoqun (id int primary key,col1 int);
sqlite> insert into Aoqun values (1,10);
sqlite> insert into Aoqun values (2,null);
sqlite>
sqlite> select * from Aoqun;
1|10
2|
sqlite> select * from Aoqun where col1 is null;
2|
sqlite>
is null
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