SQLite select where empty?
SqlSqliteSelectIsnulloremptySql Problem Overview
In SQLite, how can I select records where some_column is empty?
Empty counts as both NULL and "".
Sql Solutions
Solution 1 - Sql
There are several ways, like:
where some_column is null or some_column = ''
or
where ifnull(some_column, '') = ''
or
where coalesce(some_column, '') = ''
of
where ifnull(length(some_column), 0) = 0
Solution 2 - Sql
It looks like you can simply do:
SELECT * FROM your_table WHERE some_column IS NULL OR some_column = '';
Test case:
CREATE TABLE your_table (id int, some_column varchar(10));
INSERT INTO your_table VALUES (1, NULL);
INSERT INTO your_table VALUES (2, '');
INSERT INTO your_table VALUES (3, 'test');
INSERT INTO your_table VALUES (4, 'another test');
INSERT INTO your_table VALUES (5, NULL);
Result:
SELECT id FROM your_table WHERE some_column IS NULL OR some_column = '';
id
----------
1
2
5
Solution 3 - Sql
Maybe you mean
select x
from some_table
where some_column is null or some_column = ''
but I can't tell since you didn't really ask a question.
Solution 4 - Sql
You can do this with the following:
int counter = 0;
String sql = "SELECT projectName,Owner " + "FROM Project WHERE Owner= ?";
PreparedStatement prep = conn.prepareStatement(sql);
prep.setString(1, "");
ResultSet rs = prep.executeQuery();
while (rs.next()) {
counter++;
}
System.out.println(counter);
This will give you the no of rows where the column value is null or blank.