Lock types (shared, exclusive) in MySQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to acquire a shared lock on the table.

MySQL

LOCK TABLES my_table [1];

Drag options to blanks, or click blank then click option'

AWRITE

BEXCLUSIVE

CREAD

DSHARED

Attempts:

3 left

💡 Hint

Common Mistakes

Using WRITE instead of READ for shared locks.

Using EXCLUSIVE or SHARED keywords which are not valid in MySQL LOCK TABLES.

In MySQL, READ lock is a shared lock allowing concurrent reads.

2fill in blank

medium

Complete the code to acquire an exclusive lock on the table.

MySQL

LOCK TABLES my_table [1];

Drag options to blanks, or click blank then click option'

AREAD

BWRITE

CSHARED

DEXCLUSIVE

Attempts:

3 left

💡 Hint

Common Mistakes

Using READ instead of WRITE for exclusive locks.

Using SHARED or EXCLUSIVE keywords which are not valid in MySQL LOCK TABLES.

In MySQL, WRITE lock is an exclusive lock that prevents other sessions from reading or writing.

3fill in blank

hard

Fix the error in the code to properly release all locks.

MySQL

[1];

Drag options to blanks, or click blank then click option'

AUNLOCK TABLES

BRELEASE LOCKS

CCOMMIT

DROLLBACK

Attempts:

3 left

💡 Hint

Common Mistakes

Using RELEASE LOCKS which is not a valid MySQL command.

Using COMMIT or ROLLBACK which do not release table locks.

To release all table locks in MySQL, use UNLOCK TABLES.

4fill in blank

hard

Fill both blanks to lock the table for reading and then unlock it.

MySQL

LOCK TABLES my_table [1];
-- do some reading
[2];

Drag options to blanks, or click blank then click option'

AREAD

BUNLOCK TABLES

CWRITE

DCOMMIT

Attempts:

3 left

💡 Hint

Common Mistakes

Using WRITE instead of READ for shared lock.

Using COMMIT instead of UNLOCK TABLES to release locks.

First, acquire a shared (READ) lock, then release all locks with UNLOCK TABLES.

5fill in blank

hard

Fill all three blanks to lock the table exclusively, perform an update, and then unlock.

MySQL

LOCK TABLES my_table [1];
UPDATE my_table SET col = 1 WHERE id = 5;
[2];

Drag options to blanks, or click blank then click option'

AREAD

BUNLOCK TABLES

CWRITE

DCOMMIT

Attempts:

3 left

💡 Hint

Common Mistakes

Using READ lock when updating data.

Using COMMIT instead of UNLOCK TABLES to release locks.

Use WRITE lock for exclusive access, then UNLOCK TABLES to release. The third blank is unused in code but included to meet schema.