Fix Oracle COUNT Invalid Number Error

In Oracle, the COUNT function is used to calculate the number of rows or non-null values. If an “invalid number” error occurs when using the COUNT function, it may be because the function’s parameter contains non-numeric data.

To address this issue, appropriate conditions can be used within the COUNT function to filter out non-numeric data, such as using a WHERE clause to limit the scope of the COUNT function, or using a CASE statement to convert non-numeric data into numeric data.

Here are some sample codes demonstrating how to fix the “invalid number” error in the COUNT function.

1. Filter non-numeric data using the WHERE clause.

SELECT COUNT(column_name)
FROM table_name
WHERE column_name IS NOT NULL
AND column_name LIKE '%[0-9]%'

1. Convert non-numeric data to numeric using a CASE statement.

SELECT COUNT(CASE WHEN REGEXP_LIKE(column_name, '^[0-9]+$') THEN 1 ELSE NULL END)
FROM table_name

By using the methods mentioned above, you can resolve the issue of the COUNT function in Oracle reporting an “invalid number” error and accurately calculate the number of rows or non-null values.