oracle replace null

In Oracle, you can use the `NVL` function to replace a null value with a specified value. The syntax of the `NVL` function is as follows:

NVL(expr1, expr2)

If `expr1` is null, then `expr2` is returned; otherwise, `expr1` is returned. Here's an example:

SELECT NVL(column_name, 'replacement_value')
FROM table_name;

In the above example, if `column_name` is null, it will be replaced with the `'replacement_value'`.

Alternatively, you can use the `COALESCE` function in Oracle to achieve the same result. The syntax is similar:

SELECT COALESCE(column_name, 'replacement_value')
FROM table_name;

Both `NVL` and `COALESCE` functions can be used to handle null values in Oracle.