Hjdcti

I am able to login to the admin control panel the first time and when I logout and login again it get this message:

There has been an error processing your request
SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '0' for key 'PRIMARY', query was: INSERT INTO `admin_user_session` (`session_id`, `user_id`, `status`, `ip`) VALUES (?, ?, ?, ?)

But this works again when I get the empty ADMIN_USER_SESSION table in PHPMyAdmin.

MAKE SURE YOU HAVE A DB BACKUP

You can verify that your admin_user_session table has the primary key set to auto-increment with this query:

SELECT `AUTO_INCREMENT` FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA 'magento_db' AND TABLE_NAME = 'admin_user_session';

If you see that auto-increment is turned off, then you can fix it with this query:

ALTER TABLE 'admin_user_session' MODIFY COLUMN 'session_id' INT NOT NULL AUTO_INCREMENT;

However, if you need to do that, that is a good indication that either your DB import failed or you have some custom functionality with admin sessions that is blocking the auto-increment functionality.

Run below query your issue get resolved.

ALTER TABLE `admin_user_session` MODIFY COLUMN 'session_id' INT AUTO_INCREMENT;

CODE USED:

SELECT AUTO_INCREMENT FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA 'magento_db' AND TABLE_NAME = 'admin_user_session' LIMIT 0, 25
MySQL said: Documentation

ERROR CODE:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''magento_db' AND TABLE_NAME = 'admin_user_session' LIMIT 0, 25' at line 1

And when i tried to ALTER:

CODE USED:
ALTER TABLE 'admin_user_session' MODIFY COLUMN 'session_id' INT NOT NULL AUTO_INCREMENT;

ERROR CODE:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''admin_user_session' MODIFY COLUMN 'session_id' INT NOT NULL AUTO_INCREMENT' at line 1