InnoDB tables exist in MySQL but says they do not exist after copying database to new server

Question

I used mysqldump to export my database and then I imported it into MySQL on my other server. I can now see all my tables if I do "show tables" but I can't actually select from or describe any of them.

ERROR 1146 (42S02): Table 'mydatabase.user' doesn't exist

All of my tables are InnoDB. I saw one issue people had where they were using old_passwords, so I explicitly set that to 0 in my.cnf and I made sure all of the passwords in the mysql table were 41 hexadecimal digits as they should be for the new passwords.

Answer 1

The reason "show tables;" works is because mysqld will scan the database directory for .frm files only. As long as they exist, it sees a table definition.

If you imported the data into MySQL and this error message happens, the first thing I would immediately do is run this command: (BTW This is MySQL 5.1.45, but works in MySQL 5.x anyway)

mysql> show engines;
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                        | Transactions | XA   | Savepoints |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| BLACKHOLE  | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| FEDERATED  | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| ARCHIVE    | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance         | NO           | NO   | NO         |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
8 rows in set (0.00 sec)

If the server you imported the data into says InnoDB is disabled, then you have a big problem. Here is what you should do:

1) Drop all the Data from the New Import DB Server

2) Cleanup InnoDB Setup

3) run SHOW ENGINES; and make sure InnoDB is fully operational !!!

4) Reload the mysqldump into the new import server

Give it a Try !!!

Answer 2

I had this problem when I changed from a windows server to a Linux server. Tables are files, and windows files are case insesitive, but linux files are case sensitive.

In my aplication, in the sql queries, some times I used uppercase tablenames and other times lowercase, so, sometimes I obtained the same result as you.