Bug #6632 Command "CREATE TABLE xyz" crashs if database exists ?
Submitted: 15 Nov 2004 11:38 Modified: 19 Nov 2004 0:17
Reporter: Jaromir Prinzler Email Updates:
Status: Can't repeat Impact on me:
None 
Category:MySQL Server: Embedded Library ( libmysqld ) Severity:S1 (Critical)
Version:v4.1.7-embedded OS:Microsoft Windows (Windows XP)
Assigned to: CPU Architecture:Any

[15 Nov 2004 11:38] Jaromir Prinzler
Description:
Helo !

I hope you can understand me ? My english is bad ;-)

Now i use the embedded server version (4.1.7) from mysql.

When i log on to the server and execute first time the query
"CREATE DATABASE mydb" the server creates the database. fine !

Now i restart my program or not and send the same query to the server
"CREATE DATABASE mydb" the command "mysql_query" or "mysql_real_query"
crash the application with an exeception error "The thread tried to read or write to a virtual address for which it does not have the appropriate access".

When i use follow sequence "CREATE DATABASE IF NOT EXISTS mydb" the application crash nothing. This error exist only on the emmbedded version. When i use the real server on my suse linux 8.1 system the applikation does not crashing.

How to repeat:
Use the embedded server version from mysql, logon and call :

CREATE DATABASE mydb;
CREATE DATABASE mydb; <--- CRASHING NOW !

CREATE DATABASE IF NOT EXISTS mydb; <--- CRASHING NOT !

Suggested fix:
I think it is an filehandling problem on windows (xp) ?
[16 Nov 2004 16:52] Miguel Solorzano
I did small application modifying the sample in our Manual
for to create a database called mydb:

C:\mysql>mysample.exe
Affected rows: 1
>> mydb
>> mysql
>> test

C:\mysql>mysample.exe
Error: Can't create database 'mydb'; database existsAffected rows: -1
>> mydb
>> mysql
>> test
[17 Nov 2004 8:29] Jaromir Prinzler
My little sample for compileing under windows with gcc ! This crashs when you it called and db exists ?!

Attachment: littlesample.zip (application/x-zip-compressed, text), 1.06 KiB.

[18 Nov 2004 7:59] Jaromir Prinzler
Hello !

I have your send this litte snipped. My compiler is gcc 2.95.
When i use this code with real mysql server - it works fine ;-)
The standalone version crashs on the second "CREATE DATABASE" 
without "IF NOT EXISTS". Thats ugly !

Have a nice Day !

Greetings from berlin.

Jaromir Prinzler
[19 Nov 2004 0:17] Miguel Solorzano
Sorry I wasn't able for to test your code because I don't have
GCC on Windows and for test I need to use the VC++ compiler
which is our official compiler for the release binaries.
Your sample doesn't compile in VC++ 6.0.

Please look the sample in our Manual:

http://dev.mysql.com/doc/mysql/en/libmysqld_example.html

and just change the query for create database.....

and compile it with GCC and verify if strill you get that
crash.

Thanks in advance.