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Here is an example of how to use the SQLite IS NOT NULL condition in a SELECT statement: SELECT * FROM employees WHERE employee_id IS NOT NULL; This SQLite IS NOT NULL example will return all records from the employees table where the employee_id does not contain a null value.
Based on the SQL standard, PRIMARY KEY should always imply NOT NULL . However, SQLite allows NULL values in the PRIMARY KEY column except that a column is INTEGER PRIMARY KEY column or the table is a WITHOUT ROWID table or the column is defined as a NOT NULL column.
Syntax. Following is the basic syntax of using NULL while creating a table. SQLite> CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); Here, NOT NULL signifies that the column should always accept an explicit value of the given data type.
Description. The IS NOT NULL condition is used in SQL to test for a non-NULL value. It returns TRUE if a non-NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.
a IS b and a IS NOT b is the general form where a and b are expressions.
This is generally only seen in a IS NULL and a IS NOT NULL cases. There are also ISNULL and NOTNULL (also NOT NULL) operators which are short-hands for the previous expressions, respectively (they only take in a single operand).
The SQL understood in SQLite expressions is covered in SQLite Query Language: Expressions.
Make sure that (previous) statements have been terminated with a ; first if using the CLI.
These are all valid to negate a "null match":
expr NOT NULL
expr NOTNULL
expr IS NOT NULL
These are all valid to "match null":
expr ISNULL
expr IS NULL
Since all of the above constructs are themselves expressions the negations are also valid (e.g. NOT (expr NOT NULL) is equivalent to expr IS NULL).
Happy coding.
The proof in the pudding:
SQLite version 3.7.7.1 2011-06-28 17:39:05
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> create table x (y int null);
sqlite> select * from x where y isnull;
sqlite> select * from x where y notnull;
sqlite> select * from x where y not null;
sqlite> select * from x where y is null;
sqlite> select * from x where y is not null;
sqlite>
The problem could stem from how SQLite handles empty columns. For instance just because a column is empty does not mean it is NULL. Have you tested against ""?
SELECT * FROM project WHERE parent_id = ""
That query might return results.
In Android SQLite, field IS NULL doesn't work either.
field = 'null' does. Give it a try in your environment
This works on SQLite in SQLite Manager for Firefox:
select * from foo where not baz is not null
The query above returns rows where column [baz] is null. :-) Yarin, maybe it will work for you? (The 'not' before the column name is not a typo).
This query too finds rows where baz is null:
select * from foo where [baz] is null
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