SQL NVL: Convert String to Number

In SQL, the NVL function can be used to convert a string to a number. NVL function is used to check if an expression is NULL, if it is NULL, it returns a specified value, otherwise it returns the value of the expression. In this case, we can use the NVL function to convert a string to a number.

Here is an example:

SELECT NVL(TO_NUMBER('123'), 0) as converted_value FROM dual;

In this example, the TO_NUMBER function converts the string ‘123’ to a number, and then the NVL function returns that number. If the string cannot be converted to a number, a default value can be specified, such as 0 in the example above.