Password policies in MySQL - Mini Project: Build & Apply

Password Policies Management

📖 Scenario: You are managing a user database for a website. To keep user accounts safe, you want to create a table that stores password policies. These policies will help enforce rules like minimum length and whether special characters are required.

🎯 Goal: Create a table called password_policies with columns for policy ID, minimum length, and a flag for requiring special characters. Then insert a sample policy and finally query the table to see the policies.

📋 What You'll Learn

Create a table named password_policies with columns policy_id (integer, primary key), min_length (integer), and require_special_char (boolean).

Insert one row with policy_id 1, min_length 8, and require_special_char true.

Write a query to select all columns from password_policies.

💡 Why This Matters

🌍 Real World

Password policies are essential for securing user accounts in websites and applications. Managing these policies in a database helps enforce consistent rules.

💼 Career

Database administrators and backend developers often create and manage tables that store security policies, including password requirements.

1

Create the password_policies table

Write a SQL statement to create a table called password_policies with three columns: policy_id as an integer primary key, min_length as an integer, and require_special_char as a boolean.

MySQL

-- Your code here to create the password_policies table

Hint

Use CREATE TABLE with the column names and types exactly as specified.

2

Insert a sample password policy

Write a SQL INSERT statement to add one row into password_policies with policy_id 1, min_length 8, and require_special_char true.

MySQL

CREATE TABLE password_policies (
  policy_id INT PRIMARY KEY,
  min_length INT,
  require_special_char BOOLEAN
);
-- Your code here to insert the sample policy

Hint

Use INSERT INTO with the exact column names and values.

3

Query all password policies

Write a SQL SELECT statement to get all columns from the password_policies table.

MySQL

CREATE TABLE password_policies (
  policy_id INT PRIMARY KEY,
  min_length INT,
  require_special_char BOOLEAN
);

INSERT INTO password_policies (policy_id, min_length, require_special_char) VALUES (1, 8, TRUE);
-- Your code here to select all policies

Hint

Use SELECT * FROM password_policies; to get all rows and columns.

4

Add a new password policy

Write a SQL INSERT statement to add a second password policy with policy_id 2, min_length 12, and require_special_char false.

MySQL

CREATE TABLE password_policies (
  policy_id INT PRIMARY KEY,
  min_length INT,
  require_special_char BOOLEAN
);

INSERT INTO password_policies (policy_id, min_length, require_special_char) VALUES (1, 8, TRUE);

SELECT * FROM password_policies;
-- Your code here to insert the second policy

Hint

Use INSERT INTO with the exact column names and values for the second policy.

Practice

1. What is the purpose of MySQL's validate_password_policy variable?

easy

A. To set rules for creating strong passwords

B. To control user access privileges

C. To define database storage engines

D. To manage query cache size

Solution

1. Step 1: Understand the variable name

   The variable validate_password_policy relates to password validation rules.

2. Step 2: Identify its function

   It sets rules to ensure passwords are strong and secure.

3. Final Answer:

   To set rules for creating strong passwords -> Option A

4. Quick Check:

   Password policy = Set rules for strong passwords [OK]

Hint: Policy variables control password strength rules [OK]

Common Mistakes:

• Confusing password policy with user privileges
• Thinking it manages database storage
• Assuming it controls query cache

2. Which of the following is the correct syntax to check the current password policy level in MySQL?

easy

A. SHOW PASSWORD POLICY;

B. SELECT * FROM validate_password_policy;

C. SHOW VARIABLES LIKE 'validate_password_policy';

D. GET VARIABLES 'validate_password_policy';

Solution

1. Step 1: Recall how to view system variables

   MySQL uses SHOW VARIABLES LIKE 'variable_name'; to display variable values.

2. Step 2: Match the variable name

   The variable for password policy is validate_password_policy, so the correct syntax is SHOW VARIABLES LIKE 'validate_password_policy';

3. Final Answer:

   SHOW VARIABLES LIKE 'validate_password_policy'; -> Option C

4. Quick Check:

   SHOW VARIABLES LIKE 'validate_password_policy' [OK]

Hint: Use SHOW VARIABLES LIKE for system settings [OK]

Common Mistakes:

• Using SELECT on a variable name
• Trying non-existent commands like SHOW PASSWORD POLICY
• Using GET VARIABLES which is invalid syntax

3. Given the following commands executed in MySQL:

SET GLOBAL validate_password_length = 10;
SHOW VARIABLES LIKE 'validate_password_length';

What will be the output of the SHOW VARIABLES command?

medium

A. Variable_name: validate_password_length, Value: 10

B. Variable_name: validate_password_length, Value: 8

C. Syntax error

D. Variable_name: validate_password_policy, Value: 10

Solution

1. Step 1: Understand the SET GLOBAL command

   The command sets the global password length requirement to 10 characters.

2. Step 2: SHOW VARIABLES output

   The SHOW VARIABLES LIKE 'validate_password_length'; will display the current value, which is now 10.

3. Final Answer:

   Variable_name: validate_password_length, Value: 10 -> Option A

4. Quick Check:

   SET GLOBAL changes variable, SHOW displays updated value [OK]

Hint: SET GLOBAL changes variable, SHOW displays current value [OK]

Common Mistakes:

• Expecting default value instead of updated
• Confusing variable names
• Assuming syntax error from SET GLOBAL

4. You tried to set the password policy level with this command:

SET GLOBAL validate_password_policy = 'STRONG';

But MySQL returned an error. What is the likely cause?

medium

A. The command requires quotes around the variable name

B. The variable name is incorrect

C. You must use SET SESSION instead of SET GLOBAL

D. The value should be an integer, not a string

Solution

1. Step 1: Check variable type for validate_password_policy

   This variable expects an integer value (0,1,2) representing policy levels, not strings.

2. Step 2: Understand error cause

   Using a string like 'STRONG' causes a type mismatch error.

3. Final Answer:

   The value should be an integer, not a string -> Option D

4. Quick Check:

   Policy level = integer, not string [OK]

Hint: Policy levels use numbers, not words [OK]

Common Mistakes:

• Using string values instead of integers
• Mistyping variable name
• Confusing SET GLOBAL with SET SESSION

5. You want to enforce a password policy that requires passwords to be at least 12 characters long, include mixed case letters, numbers, and special characters. Which combination of MySQL variables should you set to achieve this?

hard

A. SET GLOBAL validate_password_length = 10; SET GLOBAL validate_password_policy = 0;

B. SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 2;

C. SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 1;

D. SET GLOBAL validate_password_length = 8; SET GLOBAL validate_password_policy = 0;

Solution

1. Step 1: Understand password length requirement

   You want at least 12 characters, so validate_password_length must be set to 12.

2. Step 2: Understand policy levels

   Policy level 2 (STRONG) requires mixed case, numbers, and special characters.

3. Step 3: Match variables to requirements

   Setting validate_password_policy = 2 and length to 12 enforces all requirements.

4. Final Answer:

   SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 2; -> Option B

5. Quick Check:

   Length 12 + policy 2 = strong password rules [OK]

Hint: Policy 2 = strong; length sets minimum characters [OK]

Common Mistakes:

• Using policy 0 or 1 which are weaker
• Setting length less than required
• Confusing policy levels with string values