MySQL > Table doesn't exist. But it does (or it should)_问答_开发者

I changed the datadir of a MySQL installation and all the bases moved correctly except for one. I can connect and USE the database. SHOW TABLES also returns me all the tables correctly, and the files of each table exists on the MySQL data directory.

However, when I try to SELECT something from the table, I get an error message that the table does not exist. Yet, this does not make sense since I was able to show the same table through SHOW TABLES state开发者_运维技巧ment.

My guess is that SHOW TABLES lists file existence but does not check whether a file is corrupted or not. Consequently, I can list those files but not access them.

Nevertheless, it is merely a guess. I have never seen this before. Now, I cannot restart the database for testing, but every other application that uses it is running fine. But that's just a guess, I've never seen this before.

Does anyone know why this is happening?

Example:

mysql> SHOW TABLES;
+-----------------------+
| Tables_in_database    |
+-----------------------+
| TABLE_ONE             |
| TABLE_TWO             |
| TABLE_THREE           |
+-----------------------+
mysql> SELECT * FROM TABLE_ONE;
ERROR 1146 (42S02): Table 'database.TABLE_ONE' doesn't exist

Just in case anyone still cares:

I had the same issue after copying a database directory directly using command

cp -r /path/to/my/database /var/lib/mysql/new_database

If you do this with a database that uses InnoDB tables, you will get this crazy 'table does not exist' error mentioned above.

The issue is that you need the ib* files in the root of the MySQL datadir (e.g. ibdata1, ib_logfile0 and ib_logfile1).

When I copied those it worked for me.

For me on Mac OS (MySQL DMG Installation) a simple restart of the MySQL server solved the problem. I am guessing the hibernation caused it.

I get this issue when the case for the table name I'm using is off. So table is called 'db' but I used 'DB' in select statement. Make sure the case is the same.

This error can also occur when setting lower_case_table_names to 1, and then trying to access tables that were created with the default value for that variable. In that case you can revert it to the previous value and you will be able to read the table.

I don't know the reason but in my case I solved just disabling and enabling the foreign keys check

SET FOREIGN_KEY_CHECKS=0;
SET FOREIGN_KEY_CHECKS=1;

stop mysqld
backup mysql folder: cp -a /var/lib/mysql /var/lib/mysql-backup
copy database folder from old machine to /var/lib/mysql
override ib* (ib_logfile* , ibdata ) from old database
start mysqld
dump dabase
mysqldump >dbase.mysql
stop mysql service
remove /var/lib/mysql
rename /var/lib/mysql-backup to /var/lib/mysql
start mysqld
create the database
mysqldump < dbase.mysql

Please run the query:

SELECT 
    i.TABLE_NAME AS table_name, 
    LENGTH(i.TABLE_NAME) AS table_name_length,
    IF(i.TABLE_NAME RLIKE '^[A-Za-z0-9_]+$','YES','NO') AS table_name_is_ascii
FROM
    information_schema.`TABLES` i
WHERE
    i.TABLE_SCHEMA = 'database'

Unfortunately MySQL allows unicode and non-printable characters to be used in table name. If you created your tables by copying create code from some document/website, there is a chance that it has zero-width-space somewhere.

I had the same problem and I searched for 2-3 days, but the solution for me was really stupid.

Restart the mysql

$ sudo service mysql restart

Now tables become accessible.

I have just spend three days on this nightmare. Ideally, you should have a backup that you can restore, then simply drop the damaged table. These sorts of errors can cause your ibdata1 to grow huge (100GB+ in size for modest tables)

If you don't have a recent backup, such as if you relied on mySqlDump, then your backups probably silently broke at some point in the past. You will need to export the databases, which of course you cant do, because you will get lock errors while running mySqlDump.

So, as a workaround, go to /var/log/mysql/database_name/ and remove the table_name.*

Then immediately try to dump the table; doing this should now work. Now restore the database to a new database and rebuild the missing table(s). Then dump the broken database.

In our case we were also constantly getting mysql has gone away messages at random intervals on all databases; once the damaged database were removed everything went back to normal.

Try to run sql query to discard tablespace before copying idb-file:

ALTER TABLE mydatabase.mytable DISCARD TABLESPACE;

Copy idb-file

ALTER TABLE mydatabase.mytable IMPORT TABLESPACE;

Restart MySql

O.k. this is going to sound pretty absurd, but humor me.
For me the problem got resolved when I changed my statement to this :

SELECT * FROM `table`

I made two changes
1.) Made the table name lower case - I know !!
2.) Used the specific quote symbol = ` : It's the key above your TAB

The solution does sound absurd, but it worked and it's Saturday evening and I've been working since 9 a.m. - So I'll take it :)

Good luck.

What worked for me, was just dropping the table, even though it didnt exist. Then I re created the table and repopulated from an sql dump done previously.

There must be some metabase of table names, and it was most likely still existing in there till i dropped it.

Had a similar problem with a ghost table. Thankfully had an SQL dump from before the failure.

In my case, I had to:

Stop mySQL
Move ib* files from /var/mysql off to a backup
Delete /var/mysql/{dbname}
Restart mySQL
Recreate empty database
Restore dump file

NOTE: Requires dump file.

I had this problem after upgrading WAMP but having no database backup.

This worked for me:

Stop new WAMP
Copy over database directories you need and ibdata1 file from old WAMP installation
Delete ib_logfile0 and ib_logfile1
Start WAMP

You should now be able to make backups of your databases. However after your server restarts again you will still have problems. So now reinstall WAMP and import your databases.

After having to reinstall MySQL I had this same problem, it seems that during the install, some configuration files that store data about the InnoDB log files, these files ib_logfile* (they are log files right?), are overwriten. To solve this problem I just deleted the ib_logfile* files.

Do mysqldump to database:

mysqldump -u user -ppass dbname > D:\Back-ups\dbname.sql

Restore database

mysql -u user -ppass dbname < D:\Back-ups\dbname.sql

Now all tables in database were restored completely. Try..

SELECT * FROM dbname.tablename;

It appears that the issue has to do (at least in mine and a few others) with invalid (corrupt?) innodb log files. Generally speaking, they simply need to be recreated.

Here are solutions, most of which require a restart of mysql.

Recreate your log files (Delete and restart mysql)
Resize your log files (MySql 5.6+ will regenerate the file for you)
If you are doing some type of a data migration, make sure you have correctly migrated the right file and given it permissions as others have already stated
Check permissions of your data and log files, that mysql is owner of both
If all else fails, you will likely have to recreate the database

In my case, i had defined a trigger on the table and then was trying to insert the row in table. seems like, somehow trigger was erroneous, and hence insert was giving error, table doesn't exist.

Copy only ibdata1 file from your old data directory. Do not copy ib_logfile1 or ib_logfile0 files. That will cause MySQL to not start anymore.

Came cross same problem today. This is a mysql "Identifier Case Sensitivity" issue.

Please check corresponding data file. It is very likely that file name is in lower case on file system but table name listed in "show tables" command is in upper case. If system variable "lower_case_table_names" is 0, the query will return "table not exist" because name comparisons are case sensitive when "lower_case_table_names" is 0.

Its possible you have a hidden character in your table name. Those don't show up when you do a show tables. Can you do a "SHOW CREATE TABLE TABLE_ONE" and tab complete the "TABLE_ONE" and see if it puts in any hidden characters. Also, have you tried dropping and remaking the tables. Just to make sure nothing is wrong with the privileges and that there are no hidden characters.

I installed MariaDB on new computer, stopped Mysql service renamed data folder to data- I solved my problem copying just Mysql\data\table_folders and ibdata1 from crashed HD MySql data Folder to the new installed mysql data folder.

I Skipped ib_logfile0 and ib_logfile1 (otherwise the server did not start service)

Started mysql service.

Then server is running.

Same exact problem after TimeMachine backup import. My solution was to stop the MySQL server and fix read-write permissions on the ib* files.

One other answer I think is worth bringing up here (because I came here with that same problem and this turned out to be the answer for me):

Double check that the table name in your query is spelled exactly the same as it is in the database.

Kind of an obvious, newbie thing, but things like "user" vs "users" can trip people up and I thought it would be a helpful answer to have in the list here. :)

In my case, when I was importing the exported sql file, I was getting an error like table doesn't exist for the create table query.

I realized that there was an underscore in my database name and mysql was putting an escape character just before that.

So I removed that underscore in the database name, everything worked out.

Hope it helps someone else too.

Here is another scenario (version upgrade):

I reinstalled my OS (Mac OS El Captain) and installed a new version of mysql (using homebrew). The installed version (5.7) happened to be newer than my previous one. Then I copied over the tables, including the ib* files, and restarted the server. I could see the tables in mysql workbench but when I tried to select anything, I got "Table doesn't exist".

Solution:

stop the mysql server e.g. mysql.server stop or brew services stop mysql
start the server using mysqld_safe --user=mysql --datadir=/usr/local/var/mysql/ (change path as needed)
run mysql_upgrade -u root -p password (in another terminal window)
shut down the running server mysqladmin -u root -p password shutdown
restart the server in normal mode mysql.server start or brew services start mysql

Relevant docs are here.

My table had somehow been renamed to ' Customers' i.e. with a leading space

This meant

a) queries broke

b) the table didn't appear where expected in the alphabetical order of my tables, which in my panic meant I couldn't see it!

RENAME TABLE ` Customer` TO `Customer`;

In my case it was SQLCA.DBParm parameter.

I used

SQLCA.DBParm = "Databse = "sle_database.text""

but it must be

SQLCA.DBParm = "Database='" +sle_database.text+ "'"

Explaination :

You are going to combine three strings :

 1. Database='              -  "Database='"

 2. (name of the database)  - +sle_database.text+

 3. '                       - "'" (means " ' "  without space)

Don't use spaces in quatermarks. Thank to my colleague Jan.

Go to :xampp\mysql\data\dbname
inside dbname have tablename.frm and tablename.ibd file.
remove it and restart mysql and try again.

I had the same issue in windows. In addition to copying the ib* files and the mysql directory under thd data directory, I also had to match the my.ini file.

The my.ini file from my previous installation did not have the following line:

innodb-page-size=65536

But my new installation did. Possibly because I did not have that option in the older installer. I removed this and restarted the service and the tables worked as expected. In short, make sure that the new my.ini file is a replica of the old one, with the only exception being the datadir, the plugin-dir and the port#, depending upon your new installation.