This is the DBConvert for MySQL & PostgreSQL Frequently Asked Questions. If you meet any problem using the application, please read this document before contacting us. We are sure that you will easily find an answer to your question, or your problem resolve here. If not, only after that you should contact us per e-mail esupport@dbconvert.com
Why should I use DBConvert for MySQL & PostgreSQL tool, not other tools?
- As well as an ultimate ease of use, this database conversion tool can give you an advantage in speed. Regularly benchmark tests show that DBConvert for MySQL & PostgreSQL product obviously stands out from the crowd of similar data conversion tools with its improved general functionality, high speed of conversion and stability of the software.
I convert my database and select utf8 as a connection charset, but all national symbols are corrupted (displayed as small squares or other wrong symbols). How can I solve the problem?
- Probably you use MySQL server earlier than version 4.1 and your MySQL data is not in utf8 charset. MySQL server earlier than v4.1 doesn't support charset conversion. That it why you should set the same connection charset as configured on your server (usually latin1).
I've got the following error message: "The dynamic link library SHLWAPI.dll could not be found in the specified path..."
- Please, install Internet Explorer version 4.01 or later. Where can I learn
more about MySQL and PostgreSQL databases?
MySQL - You should refer to the online manual pages which can be
found at http://www.mysql.com/documentation
PostgreSQL - You should refer to the online manual pages which can be found at
www.postgreql.com/docs
I've an error message: "Error 3421: Data type conversion error"
You can face this problem if there are invalid date values in the tables of your source database. Make sure that the date is entered correctly.
I encountered a problem with "MySQL server has gone away" error.
What should I do?
If mysqld gets a packet that is too large or out of order, it assumes that something has gone wrong
with the client and closes the connection. If you need big queries (for example, if you are working with big BLOB columns), you
can increase the query limit by starting mysqld with the -O max_allowed_packet=# option (default 1M). The extra memory is allocated
on demand, so mysqld will allocate more memory only when you issue a big query or when mysqld must return a big result row!
Set value to max_allowed_packet=10485760. If you using MySQLadmin select tab "my.ini Setup" and write
max_allowed_packet=10485760 after line [mysqld].
You will also get a lost connection if you are sending a packet >= 16M if your client is older than
4.0.8 and your server is 4.0.8 and above, or the other way around.
I can't connect to MySQL/PostgreSQL server. How can I solve the problem?
If you are using Virtual Server hosting you probably have no sufficient privileges to create new databases on the target MySQL/PostgreSQL server. For this case we recommend the following approach:
1. Ask your Virtual Server administrator to create blank database for you
2. Run DBConvert for MySQL & PostgreSQL and select this database as the conversion destination
3. Check option to overwrite existing MySQL/PostgreSQL database
When you complete these steps, the entire contents of the source database will be imported into the specified MySQL/PostgreSQL database.
In case a direct access to your MySQL/PostgreSQL base is denied, DBConvert for MySQL & PostgreSQL allows you to overcome such restrictions (e.g. you have no sufficient privileges to create new databases on the target MySQL/PostgreSQL server). You can do it through storing your data in dump file as the best way to present deferred conversion and gain more control over the conversion process. The program fixes the contents of the source database into a local dump file instead of sending it to MySQL/PostgreSQL server directly. The destination file will consist of MySQL/PostgreSQL statements to create all tables and to fill them with the data. Using this dump file MySQL/PostgreSQL server administrator will add data to your MySQL/PostgreSQL base.
I have a table with a long name in my PostgreSQL database, that is always shortened by convertation into MySQL. Why is it so?
There are some MySQL limits. They are listed in the following table.
See http://www.mysql.com/doc/en/Legal_names.html
| Identifier | Max length | Allowed characters |
| Database | 64 | Any character that is allowed in a directory name except `/' , `\' or `.' . |
| Table | 64 | Any character that is allowed in a file name, except `/' or `.' . |
| Column | 64 | All characters. |
| Alias | 255 | All characters. |
When I convert to PostgreSQL, the program keeps the double quote around the names of the database elements names.How can I remove the double quotes?
In PostgreSQL names (identifiers) are not case-sensitive (i.e. A=a)
In order to keep upper case in your names our program convert the data with double quotes.
To resolve the case "TableName" should be written as “tablename”.
Please, use the option to "Use lowercase" at Customization step(Database Options).
If you check this option all the names of the database elements will be converted in lower case.
For example: “TableName” will be converted into “tablename”.
After conversion date formatting of "mm/dd/yyyy" is replaced with "yyyy-mm-dd 00:00:00". Do you know of a way that I can retain the mm/dd/yyyy format after converting my base to MySQL/PostgreSQL?
The problem you described is caused by the MySQL server settings configuration. You can use in your queries DATE_FORMAT () function to modify date according your requirements. Additional info and documentation about this function you can find in MySQL server Manual/PostgreSQL server Manual
I use converter demo version and get error “Foreign key constraint fails”
Due to trial version limitation (first 10 records from each table) the error “Foreign key constraint failed” may appear. This problem comes up when you copy table records with foreign key references or records protected with other constraint methods maintaining database integrity.
I still have questions/comments about this program - Please, direct them to esupport@dbconvert.com All your feedbacks are highly appreciated.