What is the method used by Oracle to check for non-null…

1 year ago
Noah Thompson
2 minutes

In Oracle database, you can use the following methods to determine if a value is empty:

  1. Using the IS NULL keyword: The IS NULL keyword can be used to determine if a value is NULL. Example:
SELECT * FROM table_name WHERE column_name IS NULL;
  1. The IS NOT NULL keyword can be used to determine if a value is not NULL. Example:
SELECT * FROM table_name WHERE column_name IS NOT NULL;
  1. The COALESCE function can take multiple parameters and return the value of the first non-NULL parameter. Values can be compared to NULL by using them as parameters in the COALESCE function. If the result returned is equal to NULL, it means the value is empty. Example:
SELECT * FROM table_name WHERE COALESCE(column_name, NULL) IS NULL;
  1. You can use the NVL function, which takes two parameters. If the first parameter is empty, it will return the second parameter. You can use the value to be checked as the first parameter of the NVL function and set the second parameter as an empty string. If the result is equal to an empty string, it means the value is empty. Example:
SELECT * FROM table_name WHERE NVL(column_name, '') = '';

These methods can be chosen according to specific circumstances.

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