ISNULL operator in SQLite is used to check whether an expression is null or not. It returns true if the expression evaluates to
NULL, and false otherwise.
The syntax of the
ISNULL operator is as follows:
Where expression is any valid expression that can evaluate to
For example, consider the following SQLite query:
SELECT * FROM mytable WHERE mycolumn ISNULL;
This query selects all the rows from the mytable table where the mycolumn column is null.
It’s worth noting that the
ISNULL operator is equivalent to the
IS NULL operator in SQLite. Therefore, the above query can also be written as follows:
SELECT * FROM mytable WHERE mycolumn IS NULL;
Both of these queries will produce the same result.
In conclusion, the
ISNULL operator is a simple yet useful tool for checking null values in SQLite. It allows developers to easily filter out null values from their queries and ensure that only non-null values are returned.