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How to Generate Random Passwords in Oracle?

Published in Database Development 2 mins read

You can use the DBMS_RANDOM package in Oracle to generate random passwords. This package provides functions for creating random strings, including passwords.

Here's how you can do it:

1. Using the DBMS_RANDOM.STRING Function

The DBMS_RANDOM.STRING function allows you to generate a random string of a specified length with customizable character sets.

Example:

SELECT DBMS_RANDOM.STRING('U', 10) AS random_password FROM DUAL;

This query will generate a 10-character random password consisting of uppercase letters.

Character Sets:

  • 'U': Uppercase letters
  • 'L': Lowercase letters
  • 'N': Numbers
  • 'A': Alphanumeric (uppercase, lowercase, numbers)
  • 'X': Alphanumeric plus special characters (excluding spaces)
  • 'P': Printable characters (excluding spaces)

You can combine these character sets to create more complex passwords.

Example:

SELECT DBMS_RANDOM.STRING('U', 5) || DBMS_RANDOM.STRING('L', 3) || DBMS_RANDOM.STRING('N', 2) AS random_password FROM DUAL;

This query will generate a 10-character random password with 5 uppercase letters, 3 lowercase letters, and 2 numbers.

2. Using the DBMS_CRYPTO.RANDOMBYTES Function

The DBMS_CRYPTO.RANDOMBYTES function generates a random byte array. You can convert these bytes to a string representation using the UTL_RAW.CAST_TO_VARCHAR2 function.

Example:

SELECT UTL_RAW.CAST_TO_VARCHAR2(DBMS_CRYPTO.RANDOMBYTES(10)) AS random_password FROM DUAL;

This query will generate a 10-byte random password, which is then converted to a string.

Note: The resulting string may contain non-printable characters.

3. Using the DBMS_CRYPTO.RANDOM_STRING Function

The DBMS_CRYPTO.RANDOM_STRING function generates a random string of a specified length with customizable character sets.

Example:

SELECT DBMS_CRYPTO.RANDOM_STRING('A', 10) AS random_password FROM DUAL;

This query will generate a 10-character random password consisting of alphanumeric characters.

Character Sets:

  • 'A': Alphanumeric
  • 'X': Alphanumeric plus special characters (excluding spaces)

Practical Insights

  • You can use these functions to generate passwords for new user accounts or to reset forgotten passwords.
  • You can store the generated passwords in a secure location and use them for authentication purposes.
  • You should always generate strong passwords with a mix of uppercase letters, lowercase letters, numbers, and special characters.

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