I have a local website in which user adds items to Mysql DB everyday. Now I want to make a live version of the site.
But instead of adding items to both databases, I want to only add to the local database. And sync the remote database.
Local site uses XAMPP. Also I don't think replication is the way I want to do it.
I'm looking more of a PHP way of doing this task.
Currently I have no idea on how to achieve this.
Any idea on how to do this?
The quickest way to do this would be with MySQL, but if you want to use strictly PHP, there're two ways to go about this if you want the live data to only reflect the local data (i.e. you're fine with deleting all data and re-pulling data). Because this solution is in PHP, you will have to loop through each individual table. You can run a PHP script that uses either PDO or MySQLi, but you will need one of two deletion strategies listed below:
1) TRUNCATE and SELECT FROM (Fast, but has potential security risks) This is a bigger risk because the MySQL permissions to TRUNCATE are DROP and ALTER. Not commands you want a regular database user to have access to. Here's the SQL to pull it off:
TRUNCATE live_database_name.table_name
INSERT INTO live_database_name.table_name SELECT * FROM local_database_name.table_name
2) DELETE FROM and SELECT FROM (Slower the more data you have, but safer). This solution is slower because you have to walk through each entry in a table rather than dropping and re-creating the table. However, DELETE is seen as a safer permission to give a database user as they can't DROP entire tables. Here's what you'll need to pull it off:
DELETE FROM live_database_name.table_name
INSERT INTO live_database_name.table_name SELECT * FROM local_database_name.table_name
If you don't want to setup a replication scheme, why not just use (2 or 3) cron jobs, dump local / dump remote / update remote with local dump. And no, that isn't the best way to do this, but it works...
With just (2), dump local / update remote with local dump, run daily # 1:00AM dump, and !:15AM update
0 1 * * * mysqldump --host="localhost" --user="user" --password="password" database_name > backup_name.sql
15 1 * * * mysql --host="remote_host" --user="user" --password="password" --port="3306" database_name < backup_name.sql
I am using windows XP. I am creating a table in phpMyAdmin using its built-in create table feature,
my database name is ddd.
It generates the following code:
CREATE TABLE `ddd`.`mwrevision` (
`asd` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`sddd` INT NOT NULL
) ENGINE = INNODB;
and the following error shows up:
MySQL said:
#1146 - Table 'ddd.mwrevision' doesn't exist
What might be the problem?
I also had same problem in past. All had happend after moving database files to new location and after updating mysql server. All tables with InnoDB engine disappeared from my database. I was trying to recreate them, but mysql told me 1146: Table 'xxx' doesn't exist all the time until I had recreated my database and restarted mysql service.
I think there's a need to read about InnoDB table binaries.
I had the same problem and can't get a good tip for this over the web, so I shared this for you and for all who needs.
In my situation I copy a database (all files: frm, myd) to the data folder in MySQL data folder (using Wamp at home). All thing was OK until I want to create a table and have the error #1146 Table '...' doesn't exist!.
I use Wamp 2.1 with MySQL version 5.5.16.
My solution:
Export the database to file;
verify if exported file is really OK!!;
drop the database where I have issues;
create a new database with the same name that the last;
import the file to the database.
FOR ME IS PROBLEM SOLVED. Now I can create tables again without errors.
Restarting MySQL works fine for me.
In my case I ran this command even if the table wasn't visible in PhpMyAdmin :
DROP TABLE mytable
then
CREATE TABLE....
Worked for me !
Check filenames.
You might need to create a new database in phpmyadmin that matches the database you're trying to import.
I had the same problem. I tried to create a table in mysql and got the same error. I restarted mysql server and ran the command and was able to create/migrate table after restating.
Today i was facing same problem. I was in very difficult situation but what id did i create a table with diffrent name e.g (modulemaster was not creating then i create modulemaster1) and after creating table i just do the rename table.
I encountered the same problem today. I was trying to create a table users, and was prompted that ERROR 1146 (42S02): Table users doesn't exist, which did not make any sense, because I was just trying to create the table!!
I then tried to drop the table by typing DROP TABLE users, knowing it would fail because it did not exist, and I got an error, saying Unknown table users. After getting this error, I tried to create the table again, and magically, it successfully created the table!
My intuition is that I probably created this table before and it was not completely cleared somehow. By explicitly saying DROP TABLE I managed to reset the internal state somehow? But that is just my guess.
In short, try DROP whatever table you are creating, and CREATE it again.
As pprakash mentions above, copying the table.frm files AND the ibdata1 file was what worked for me.
In short:
Shut your DB explorer client (e.g. Workbench).
Stop the MySQL service (Windows host).
Make a safe copy of virtually everything!
Save a copy of the table file(s) (eg mytable.frm) to the schema data folder (e.g. MySQL Server/data/{yourschema}).
Save a copy of the ibdata1 file to the data folder (i.e., MySQL Server/data).
Restart the MySQL service.
Check that the tables are now accessible, queryable, etc. in your DB explorer client.
After that, all was well. (Don't forget to backup if you have success!)
Column names must be unique in the table. You cannot have two columns named asd in the same table.
run from CMD & %path%=set to mysql/bin
mysql_upgrade -u user -ppassword
Recently I had same problem, but on Linux Server. Database was crashed, and I recovered it from backup, based on simply copying /var/lib/mysql/* (analog mysql DATA folder in wamp). After recovery I had to create new table and got mysql error #1146. I tried to restart mysql, and it said it could not start. I checked mysql logs, and found that mysql simply had no access rigths to its DB files. I checked owner info of /var/lib/mysql/*, and got 'myuser:myuser' (myuser is me). But it should be 'mysql:adm' (so is own developer machine), so I changed owner to 'mysql:adm'. And after this mysql started normally, and I could create tables, or do any other operations.
So after moving database files or restoring from backups check access rigths for mysql.
Hope this helps...
The reason I was facing this was because I had two "models.py" files which contained slightly different fields.
I resolved it by:
deleting one of the models.py files
correcting references to the deleted file
then running manage.py syncdb
I got this issue after copying mytable.idb table file from another location. To fix this problem I did the following:
ALTER TABLE mydatabase.mytable DISCARD TABLESPACE;
Copy mytable.idb
ALTER TABLE mydatabase.mytable IMPORT TABLESPACE;
Restart MySql
I had the same issue. It happened after windows start up error, it seems some files got corrupted due to this. I did import the DB again from the saved script and it works fine.
I had this problem because of a trigger not working..Worked after I deleted the trigger.
In my case, MySQL's parameter; lower_case_table_names was configured = 0.
It causes queries related with using upper cases will not work.
For me it was a table name upper/lower case issue. I had to make sure that table case name matched in a delete query, table notifications was not the same as Notifications. I fixed it by matching table name case with query and what MySQLWorkbench reported.
What is wierd is that this error showed up in a worked sql statement. Don't know what caused this case sensitivity. Perhaps an auto AWS RDS update.
if you are modifying mysql bin->data dir's and after that, your database import will not works
so you need to close wamp and after that start wamp
now database import will work fine
Make sure you do not have a trigger that is trying to do something with the table mentioned in the error. I was receiving Error Code: 1146. Table 'exampledb.sys_diagnotics' doesn't exist on insert queries to another table in my production database. I exported the table schemas of my production database then searched for instances of exampledb.sys_diagnotics the schema SQL and found a debugging insert statement I had added to a table trigger in my development environment but this debug statement had been copied to production. The exampledb.sys_diagnotics table was not present on my production database. The error was resolved by removing the debug statement in my table trigger.
Here's the situation:
I have a mySQL db on a remote server. I need data from 4 of its tables. On occasion, the schema of these tables is changed (new fields are added, but not removed). At the moment, the tables have > 300,000 records.
This data needs to be imported into the localhost mySQL instance. These same 4 tables exist (with the same names), but the fields needed are a subset of the fields in the remote db tables. The data in these local tables is considered read-only and is never written to. Everything needs to be run in a transaction so there is always some data in the local tables, even if it is a day old. The localhost tables are used by an active website, so this entire process needs to complete as quickly as possible to minimize downtime.
This process runs once per day.
The options as I see them:
Get a mysqldump of the structure/data of the remote tables and save to file. Drop the localhost tables, and run the dumped sql script. Then recreate the needed indexes on the 4 tables.
Truncate the localhost tables. Run SELECT queries on the remote db in PHP and retrieve only the fields needed instead of the entire row. Then loop through the results and create INSERT statements from this data.
My questions:
Performance wise, which is my best option?
Which one will complete the fastest?
Will either one put a heavier load on the server?
Would indexing the
tables take the same amount of time in both options?
If there is no good reason for having the local d/b be a subset of the remote, make the structure the same and enable database replication on the needed tables. Replication works by the master tracking all changes made, and managing each slave d/b's pointer into the changes. Each slave says give me all changes since the last request. For a sizeable database, this is far more efficient than any alternative you have selected. It comes with only modest cost.
As for schema changes, I think the alter information is logged by the master, so the slave(s) can replicate those as well. The mechanism definitely replicates drop table ... if exists and create table ... select, so alter logically should follow, but I have not tried it.
Here it is: confirmation that alter is properly replicated.
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Closed 12 years ago.
Possible Duplicate:
How do I quickly rename a mysql database (change schema name)?
hi ,
plz help me to rename the database name in mysql
You should not use rename database as it will result in data loss http://dev.mysql.com/doc/refman/5.1/en/rename-database.html
Instead use alter database syntax http://dev.mysql.com/doc/refman/5.1/en/alter-database.html
You can choose any of the following ways to rename a database in MySQL.
If you have access to the directory where MySQL stores its databases. As per default MySQL installations, this is usually in the data directory under the directory where MySQL was installed. Locate the name of required database under the data directory and rename it as desired. Note: You must stop MySQL Server before renaming the database and may restart it after this operation. In this case, you may also grant permissions again on the renamed database. This only works for MyISAM tables. If you have tables with other storage engines than use the method described below.
Another way that seems safest, is to use mysqldump utility to back up the old database. Create a new database with desired name, then restore the dumped database under this database using the mysql utility. Finally, use the DROP DATABASE old_database_name; command to get rid of the old database. This is the safest method.
I'm creating locally a big database using MySQL and PHPmyAdmin. I'm constantly adding a lot of info to the database. I have right now more than 10MB of data and I want to export the database to the server but I have a 10MB file size limit in the Import section of PHPmyAdmin of my web host.
So, first question is how I can split the data or something like that to be able to import?
BUT, because I'm constantly adding new data locally, I also need to export the new data to the web host database.
So second question is: How to update the database if the new data added is in between all the 'old/already uploaded' data?
Don't use phpMyAdmin to import large files. You'll be way better off using the mysql CLI to import a dump of your DB. Importing is very easy, transfer the SQL file to the server and afterwards execute the following on the server (you can launch this command from a PHP script using shell_exec or system if needed) mysql --user=user --password=password database < database_dump.sql. Of course the database has to exist, and the user you provide should have the necessary privilege(s) to update the database.
As for syncing changes : that can be very difficult, and depends on a lot of factors. Are you the only party providing new information or are others adding new records as well? Are you going modify the table structure over time as well?
If you're the only one adding data, and the table structure doesn't vary then you could use a boolean flag or a timestamp to determine the records that need to be transferred. Based on that field you could create partial dumps with phpMyAdmin (by writing a SQL command and clicking Export at the bottom, making sure you only export the data) and import these as described above.
BTW You could also look into setting up a master-slave scenario with MySQL, where your data is transferred automatically to the other server (just another option, which might be better depending on your specific needs). For more information, refer to the Replication chapter in the MySQL manual.
What I would do, in 3 steps:
Step 1:
Export your db structure, without content. This is easy to manage on the exporting page of phpmyadmin. After that, I'd instert that into the new db.
Step 2:
Add a new BOOL column in your local db in every table. The function of this is, to store if a data is new, or even not. Because of this set the default to true
Step 3:
Create a php script witch connects to both databases. The script needs to get the data from your local database, and put it into the new one.
I would do this with following mysql methods http://dev.mysql.com/doc/refman/5.0/en/show-tables.html, http://dev.mysql.com/doc/refman/5.0/en/describe.html, select, update and insert
then you have to run your script everytime you want to sync your local pc with the server.