How to Fix SQLite Error Database is Locked – Error Code 5

This blog summarized on how to fix SQLite Error Database is Locked including Error Code 5 with helps of either manual method or automated solution.

It is quite often, if you are using SQLite then you face some issues. Sometimes while doing the transaction, you might come through an error in which the database gets locked and the following message appears:

“error code 5: Database is locked”

So, if you are facing the same then you are at the right place to find the solution of query how to fix SQLite error database is locked. Let’s find out the reasons of this error before going for its solution.

Reasons Responsible for Error Database is Locked

This error code occurs when the user tries to perform two inappropriate operations on a database at the same detail and on the same database connection. This error code shows that an operation can’t be continued due to encounter with a transaction that uses the same database connection or the transaction that uses a distinct database connection by using a shared cache.

 Also Read: Best Solution to Fix SQLite Error Malformed Database Schema

Assume a scenario, when you attempt to run a DROP TABLE statement meanwhile a different thread is trying to read from the same table and that also on the same database connection. Then, the table would be deleted and therefore, the other thread will be unable to read from it.

Different Scenarios of SQLite Database is Locked Error Code 5

The different scenarios when you can receive error code 5: database is locked. These are listed below:

• The situation in which you want to CREATE or DROP an index or a table whilst the SELECT statement is in a pending state, the database will get locked. The reason is that the users think that the SELECT statement has been finished as Sqlite3_() has returned the value SQLITE_DONE. Although, this is a different case since SELECT statement is not considered as complete until Sqlite3_reset() or Sqlite3_finalize() are called.
• When you attempt to write in a table on which the SELECT operation is still active.
• When you attempt to do 2 SELECT on the same table and at the same time in a multi-thread application and the SQLite has not been fixed to do the same, the database may get locked.

One thing you should keep in mind that SQLITE_LOCKED should not be confused with a SQLITE_BUSY parameter. This is because of SQLITE_LOCKED points to a situation when there is a conflict between two transactions running on the same database connection. Moreover, the SQLITE_BUSY shows that two transactions are running on different database connection and in different processes they have conflicted.

 Also Read: How to Repair SQLite Database and Restore SQLite Database

Resolve SQLite Locked Error

To fix “SQLite database is locked error code 5” the best solution is to create a backup of the database, which will have no locks on it. After that, replace the database with its backup copy. Follow the following script to do the same where .x.Sqlite is the Sqlite database file:
$Sqlite3 .x.Sqlite

Sqlite> .backup main backup.Sqlite

Sqlite> .exit

Further, you have a file named backup.Sqlite in the same directory. Then you have to swap your old database with the backup copy of the database. So, the backup copy will not have any locks, the SQLite database is locked error code 5 will not be conflicted.

$mv .x.Sqlite old.Sqlite

$mv backup.Sqlite .x.Sqlite

After the successful execution of the above script, you can further access the SQLite database. Investigate that the database is allowing both the read and write operations to run successfully, and then you can delete the old SQLite database file.

 Also Read: Reasons & Solution for Corrupt SQLite Database

Automated Method to Fix SQLite Locked Error

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There is an alternate solution that is Aryson SQLite Database Recovery tool. It supports the corrupt SQLite database created by SQLite2 and SQLite3. It can easily recover the SQLite database which is corrupt due to various reasons.

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