MySQL Forums - MySQL Connector/C (libmysql)

"error while loading shared libraries: libmysqlclient.so.15:" Huh? (no replies)

Bill Phan — Wed, 24 Apr 2013 04:40:36 +0000

I infrequently get the error "error while loading shared libraries: libmysqlclient.so.15:" when running a C program that queries a mySQL 5
DB, calls a stored procedure and does a LOAD DATA INFILE. The code is run as
a daily cron job on a CentOS 6.4 box and the error might not happen for days but once it occurs I have to re-compile the source code to get it working again.

The strange thing is, I thought executables on Linux were stand-alone and didn't
need to load any libraries on the fly in order to function.

Here's the gcc command line I'm using to compile the code:

gcc -o ImportData.out $(mysql_config --cflags) ImportData.c $(mysql_config --libs)

The program compiles w/no errors and by verifying the mySQL 5 tables are created correctly and all the data imported into the tables appears to work correctly.

Google didn't really turn up anything useful which is why I'm here now.

Table 'xxx' doesn't exist (no replies)

Juergen Gnoss — Sun, 07 Apr 2013 08:05:08 +0000

strange thing happens.

have a look:

login onto console

database and table new created

then
==================================================================
mysql> insert into `miguel.errortext` (`name`) values ('machine stopped');
Query OK, 1 row affected (0.03 sec)

mysql> select * from `miguel.errortext`
-> ;
+----+-----------------+
| id | name |
+----+-----------------+
| 1 | machine stopped |
| 2 | machine error 0 |
| 3 | machine error 1 |
| 4 | machine error 2 |
| 5 | machine error 3 |
| 6 | machine error 4 |
| 7 | machine error 5 |
| 8 | machine error 6 |
| 9 | machine error 7 |
| 10 | machine error 8 |
| 11 | machine error 9 |
+----+-----------------+
11 rows in set (0.00 sec)

mysql> SELECT * FROM miguel.errortext;
ERROR 1146 (42S02): Table 'miguel.errortext' doesn't exist

mysql> show tables;
+------------------+
| Tables_in_miguel |
+------------------+
| miguel.errorlog |
| miguel.errortext |
| miguel.operators |
+------------------+
3 rows in set (0.00 sec)

===============================================================

after the first insert I run a simple c-programm
it has a select on that table

shows:

07.03.2013 02:13:17, mysql connected
SELECT * FROM miguel.errortext
rows found : 1

and it inserts the 10 records

the first select on console

select * from `miguel.errortext`

shows the correct result:

after that I run the c program again and it failed

07.03.2013 02:13:19, mysql connected
07.03.2013 02:13:19, error in SELECT * FROM miguel.errortext

running a select again on the console and surprise:

ERROR 1146 (42S02): Table 'miguel.errortext' doesn't exist

but tables are there.
what's happening there?

I searched the forum and internet for that problem.
mostly that seems to happen after some table copy, dump or so,
but that's not in my case.
I work on a ubuntu box

mysql -?
mysql Ver 14.14 Distrib 5.5.29, for debian-linux-gnu (x86_64) using readline 6.2
Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

snip

Variables (--variable-name=value)
and boolean options {FALSE|TRUE} Value (after reading options)
--------------------------------- ----------------------------------------
auto-rehash TRUE
auto-vertical-output FALSE
character-sets-dir (No default value)
column-type-info FALSE
comments FALSE
compress FALSE
debug-check FALSE
debug-info FALSE
database (No default value)
default-character-set auto
delimiter ;
enable-cleartext-plugin FALSE
vertical FALSE
force FALSE
named-commands FALSE
ignore-spaces FALSE
init-command (No default value)
local-infile FALSE
no-beep FALSE
host (No default value)
html FALSE
xml FALSE
line-numbers TRUE
unbuffered FALSE
column-names TRUE
sigint-ignore FALSE
port 3306
prompt mysql>
quick FALSE
raw FALSE
reconnect TRUE
socket /var/run/mysqld/mysqld.sock
ssl FALSE
ssl-ca (No default value)
ssl-capath (No default value)
ssl-cert (No default value)
ssl-cipher (No default value)
ssl-key (No default value)
ssl-verify-server-cert FALSE
table FALSE
user (No default value)
safe-updates FALSE
i-am-a-dummy FALSE
connect-timeout 0
max-allowed-packet 16777216
net-buffer-length 16384
select-limit 1000
max-join-size 1000000
secure-auth FALSE
show-warnings FALSE
plugin-dir (No default value)
default-auth (No default value)

Multithreading: mysql_ping() error. (no replies)

Alexandre Kalendarev — Tue, 02 Apr 2013 13:40:15 +0000

I create connection pool with mysql option MYSQL_OPT_RECONNECT = 1 and use one uniq connection by one thread. But, my MySQL server is overload and I have error 2013: "Lost connection to MySQL server during query query" sometimes.

So, I use mysql_ping() before each query execution (mysql_query) and sometimes I have SIGSEG error.

Can I use mysql_ping() in the worker thread, if it use uniq connections ( the each thread use only one connection from connection pool)

Unable to load DLL on 2008 R2 if conn = mysql_init(NULL); (no replies)

Joseph Cameron — Thu, 28 Feb 2013 14:41:05 +0000

The full DLL will load and run on Win 7.

The full DLL will not load on Server 2008 R2.

If I remove all reference to MySql for Connector/C
the DLL will load and run.

If I only have:
conn = mysql_init(NULL);
mysql_close(conn);

The DLL does not load (error 126).

DLL was compiled with VS 2010 Express, both on Win 7 the server.

Comments (no replies)

Jens Ruena — Tue, 29 Jan 2013 13:41:40 +0000

How do I get comments within a function form a database dump into the database?

mysql user -h host < dump.txt

dump.txt
=============

DROP FUNCTION IF EXISTS `foo`;
DELIMITER $$

CREATE DEFINER=`user`@`%` FUNCTION `foo`() RETURNS bigint(1)

BEGIN

SET @var1 = "TEST";
#please keep this comment

return 1;
END$$

DELIMITER ;

Stored procedure - Commands out of sync after mysql_free_result() (no replies)

Tushar Bindal — Tue, 29 Jan 2013 05:52:36 +0000

I have written the following code to call a stored procedure which returns a temporary table and stores a value in a variable:

MYSQL *conn;
MYSQL_RES *res;
MYSQL_ROW row;

void read_data()
{
int num_cols, j;

/* create the string for first statement */
strcpy(buff, "CALL proc_read_user('");
concat(buff, date_start);
concat(buff, "', '");
concat(buff, date_end);
concat(buff, "', '");
concat(buff, user_id);
concat(buff, "', '");
concat(buff, curr_time);
concat(buff, "', @");
concat(buff, tot_time);
concat(buff, ");");

if(mysql_query(conn, buff))
{
fprintf(fptr_errors, "Error : Procedure not called : %s\n", mysql_error(conn));
exit(1);
}

if(!(res = mysql_store_result(conn)))
{
fprintf(fptr_errors, "no result returned by procedure\n");
exit(1);
}

num_cols = mysql_num_fields(res);
while ((row = mysql_fetch_row(res)) != NULL)
{
fprintf(fptr_reads, "%s", row[0]);
for(j=1;j {
fprintf(fptr_reads, "\t||\t%s", row[j]);
}
fprintf(fptr_reads, "\n\n");
}

mysql_free_result(res);
res = mysql_store_result(conn);
mysql_free_result(res);

/* Second statement */
strcpy(buff, "SELECT @");
concat(buff, tot_time);
concat(buff, ";");

if (mysql_query(conn, buff))
{
fprintf(fptr_errors, "Error in reading the total time : %s\n", mysql_error(conn));
exit(1);
}

if(!(res = mysql_use_result(conn)))
{
fprintf(fptr_errors, "No result returned by select query\n");
exit(1);
}

while ((row = mysql_fetch_row(res)) != NULL)
{
//if(row[0]==NULL) cout< cout< fprintf(fptr_reads, "Total time : %s second(s)\n", row[0]);
}
}

------------------------------------------------------------------------

The two MySQL statements that are executed are :

CALL proc_read_user('2008-01-01', '2013-12-31', 'ashish', '23:59:59', @tot_time_01);

SELECT @tot_time_01;

The first statement is executed successfulyy and the temporary table is retuned and printed.
However, after that when I execute the second statement, the error is igven:
Commands out of sync; you can't run this command now

I have used mysql_store_result() as well as mysql_free_result() functions before executing the second statement.
Then why does this error occur? How can the second statement be executed correctly?

Archive has no index; run ranlib to add one in Dev C++ (no replies)

zahid ullah — Sun, 27 Jan 2013 07:27:25 +0000

I converted mysqlclient.lib to mysqlclient.a using ar command
ar rcs mysqlclient.a mysqlclient.lib

now am keep getting that error Archive has no index; run ranlib to add one

I run ranlib on mysqlclient.a but still getting the above no index error :( do not know how to fix this , so need help
ranlib libmysqlclient.a

am using dev c++ for my project

Access Violation during Intialization. (no replies)

David Pratt — Mon, 07 Jan 2013 13:29:57 +0000

I have been experimenting with the C API using C++Builder XE2, but when I call mysql_init, it generates an access error. System configuration is:

OS: Windows 7 64bit
MySQL server: 5.5.27 64bit
libmysql.dll ver: 5.5.29 32 bit

I am linking against a generated import lib using emb's implib, as Embarcadero's compilers use OMF library format as opposed to the COFF format used by VS. Everything links fine, but when I run teh code, it generaates an access error. I have been able to trace the error to inside mysql_server_init, but I get lost in the assembly code from there. From what I can see, I believe it may be the call to init_embedded_server that is causing a problem. The access violation actually occurs in a section of C++Builder's runtime library that is unloading modules, if this helps at all. The Basic code follows:

{
  MySQL= NULL;
  mysql_init(MySQL);
}

The libmysql.dll is already previously loaded during program startup.

libmysql.dll for version 5.1.66 (1 reply)

Edward Hooper — Wed, 26 Dec 2012 18:00:22 +0000

I'm building an application in Lazarus on Windows XP (32-bit) with a MySQL database running on CentOS 6.3. The DBMS version is 5.1.66 so I need libmysql.dll of the same version. All I can find for the connectors is v6.0.2. Where are the archives kept? I went to the archives and I don't see connectors for C there, just Java, PHP, etc.

Thanks in advance,

Edward Hooper

Error compiling a simple C program (no replies)

Joseph Earl — Mon, 10 Dec 2012 05:50:06 +0000

OS: Windows XP service pack 3
MySQL Server v 5.5
C Compiler MINGW - Minimalist GNU for windows

I am trying to write a simple C program to access a mysql database as follows:
#include
#include

int main(int argc, char **argv)
{
printf("MySQL client version: %s\n", mysql_get_client_info());
}
I have copied the include files that came with mysql server 5.5 to the include directory on the MINGW compiler directory structure.

When I try to compile I get the following error:

In file included from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/io.h:20:0,
from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/my_global.h:127,
from loadpcode.c:6:
c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/sys/types.h:100:17: error: two or more data types in declaration specifiers
c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/sys/types.h:110:19: error: two or more data types in declaration specifiers
c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/sys/types.h:119:18: error: conflicting types for 'SSIZE_T'
In file included from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/winnt.h:192:0,
from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/windef.h:253,
from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/windows.h:48,
from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/winsock2.h:22,
from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/my_global.h:125,
from loadpcode.c:6:
c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/basetsd.h:111:18: note: previous declaration of 'SSIZE_T' was here
In file included from c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/my_global.h:1039:0,
from loadpcode.c:6:
c:\mingw\bin\../lib/gcc/mingw32/4.7.2/../../../../include/my_dbug.h:108:20: fatal error: crtdbg.h: No such file or directory
compilation terminated.

Am I using the correct include files? I have also tried the include files from Connector C 6.0.2 but get similar errors?

What am I doing wrong?

Server to Clienst: Transmitting just ASCII for numericals? (no replies)

Jens Ruena — Fri, 07 Dec 2012 11:05:14 +0000

Hi,

While investigating performance problems in our legacy multi-client application, I found that our clients read all values (ints, doubles, etc.) from the MYSQL C-Connector in ASCII literals. That means all numbers are coded in text (the String “123” for the int 123). Most of our data consist of numerical values (ints and doubles). Our main performance problem are queries that take to long, so I am wondering:
* Does MySQL transmit numerics as ASCII? So the server has to do the sprintf(), and the client has to do the sscanf()?
* Is there a way to get binaries form the MySQL server? (we are using mysql_fetch_row())
* Is MySQL itself just storing text? (I don't think so)
* Is the transmission of ASCII data not considered a common bottleneck?

Thanks a lot

mysql_use_result vs. prepared statement (no replies)

Julien Coloos — Fri, 09 Nov 2012 16:06:54 +0000

In order to minimize memory consumption on the client side, one can use mysql_query/mysql_real_query and mysql_use_result, or use a prepared statement with cursor.

However the documentation (http://dev.mysql.com/doc/refman/5.6/en/mysql-use-result.html) warns that:

Quote

On the other hand, you shouldn't use mysql_use_result() if you are doing a lot of processing for each row on the client side, or if the output is sent to a screen on which the user may type a ^S (stop scroll). This ties up the server and prevent other threads from updating any tables from which the data is being fetched.

Is this always true, in all versions of MySQL server ?
I tried fetching ~1 million entries from a 5.5 server at a really slow pace (1 per second), and was still able to update the entries in the table while doing so. Maybe the table (or parts of it only ?) would be locked in certain conditions ?
If so, do prepared statements with cursor prevent this kind of locking ? or does the locking (under similar conditions maybe) also apply with prepared statements ?

libmysqlclient.a with -fPIC flag (Position Independent Code) (no replies)

Evgeny Barabanov — Tue, 30 Oct 2012 13:05:25 +0000

I want to include few database connectors in my own wrapper, which will be distributed as shared library. In order to do this, I need a version of libmysqlclient which is compiled with -fPIC flag (otherwise I get an error:
(client.c.o): relocation R_X86_64_32S against `client_errors' can not be used when making a shared object; recompile with -fPIC) . I didn't found such version on official site, so there is a question:
Is there anywhere libmysqlclient.a compiled with -fPIC? If no, how can I compile it form sources with this flag?

Checking the goodness of MYSQL* handle (no replies)

Giovanni Txxxxxx — Thu, 11 Oct 2012 09:29:50 +0000

Hello everybody,

I've written a C client application with a function that tries to do some checks before performing any query to the server.

In details, it uses mysql_ping(), eventually re-inits the connection with mysql_init() and mysql_real_connect() and then calls mysql_query().

I want to add a check at the beginning of the function, about the MYSQL* handle which is used also as parameter by mysql_ping().

In fact, if the handle is somehow unusable (overwritten / subturfuged / damaged / anything) I get a segfault when using it.
I tried both this checks:

===============
MYSQL* mysql;
[...]
if (mysql!=NULL) mysql_ping(mysql);
if (mysql) mysql_ping(mysql)
===============

but they do not work (segfault if handle is already damaged).

The only mean I have to avoid the segfault is to reinitialize the handle with mysql_init(), just before the point I know the handle is already damaged.

What I want to do is then the following:

===============
if (handle is not ok) handle=mysql_init()
===============

But I don't know how to check if the handle is ok without getting a segmentation fault.

Thank you in advance for any suggestions!

WinCE 5.0 (1 reply)

Juan A — Mon, 08 Oct 2012 00:52:26 +0000

Has anyone tried to build/compile (successfully) the C connector for a WinCE 5.0 target?

I have our target board SDK that we use to compile custom applications for it - using custom compiler options for our specific hardware...

Im thinking I can do something similar for the MySQL-C connector since the source is provided...

However, I cant seem to get anything happening on VS2005... Well not anything that builds, and certainly nothing that allows me to change the configuration to allow me to use our board SDK.

CMake does generate solution files that I can open, but none of them build. Am I tackling this wrong?

Should CMake be able to target my custom board (ARM derivative)?

mysql_stmt_next_result for queries returning a single result set (no replies)

Tony Izzo — Fri, 28 Sep 2012 20:32:43 +0000

I'm interested in using the mysql_stmt_next_result() API for retrieving results for a stored procedure call which may or may not return multiple result sets. I am trying to determine whether I can use this same method for a plain old SQL prepared SELECT statement that returns only a single result set, or if it is only permitted for executing a CALL.

In other words, if I pass an arbitrary statement into a function that prepares, binds, and executes that statement, does my function need to handle two separate execution paths for CALL and SELECT statements, or will a function that correctly handles CALL statements returning an arbitrary number of result sets also work with a normal SELECT? Thanks.

Tony

MYSQLConnector and XCODE4.4 - need i386 arch build please! (1 reply)

Reggie Virmani — Thu, 26 Jul 2012 01:46:40 +0000

Hi, I have downloaded and installed the MYsql commiunity server on my
MAc OS 10.7. While everything is great, I am having a little trouble
using the connector for IOS development (as I am sure you already have
heard). When trying to use the mysqlclient.dyslib.18, the sim crashes
telling me its not in the i386 arch. Can you please let me know if you
have a i386 compatible or will i need to recompile the library again. If
I neeed to recompile the library again, which is the best package to
download?

version errror? (1 reply)

Lucas Beltrán — Mon, 09 Jul 2012 08:06:53 +0000

Hi,

I downloaded mysql-connector-c-noinstall-6.0.2-win32.zip

http://dev.mysql.com/downloads/mirror.php?id=377978

I checked that libmysql.dll is from 2009. I need latest version, but the file is from ¡2009!.

Please, where I can find latest version?.

Also, with this download, I called to mysql_get_client_info().

It gives me out 6.0.0, but in web page says 6.0.2.

What is wrong?.

Thank you very much.

Unresolved symbols if using MySQL x64 @ Win7 (no replies)

Miguel Cardenas — Wed, 13 Jun 2012 04:35:06 +0000

Hello friends

I have a doubt... After spending hours to compile an application with libmysql C API and resulting always on "unresolved symbol mysql_..." I tried to uninstall MySQL x64 and installed MySQL x86 (32 bits) and magically my application compiled and linked.

My question is if I have to do a different procedure or configuration to compile using the 64bit version?

I have Windows 7 x64 with AMD64 processor and Visual C++ 2010 Express, so it would be nice to be able to use the 64bit version of MySQL...

Thanks for your help!

Miguel

access denied (no replies)

Aaron Kerti — Wed, 13 Jun 2012 00:48:41 +0000

Hi, I'm using the c api and trying to access data off my mysql server(which is remote). When I try to connect it says access denied for user. How do I fix this? Is it something wrong with my server or code? I'm getting an error code 1045. And the thing is I can edit the tables on a php script thats on the web server.

#include "stdafx.h"
#include

#include
#include

using namespace std;

int main()
{
MYSQL *conn;
MYSQL_RES *result;
MYSQL_ROW row;

std::cout << "start" << std::endl;

conn = mysql_init(NULL);

if(conn == NULL)
{
std::cout << "failed to initialize connection" << std::endl;
}

mysql_real_connect(conn, "216.51.232.61", "username", "password", "a1298_userAccounts", 0, "2082", 0);
cout << mysql_error(conn) << endl;

int query_result = mysql_query(conn, "SELECT * FROM UserAccounts");
std::cout << query_result << std::endl;

result = mysql_store_result(conn);

while ((row = mysql_fetch_row(result)))
{
std::cout << row[2] << std::endl;

if(row[2] == "shadyvillian")
{
if(row[3] == "a")
{
std::cout << "login successful" << std::endl;
}
}

}

mysql_free_result(result);
mysql_close(conn);

}

how to write a C application that implement loadblance/failover (no replies)

gu lilan — Sat, 09 Jun 2012 08:56:19 +0000

hi all:

now i'll write a C program .
And it's need to implements loadblance/failover function.
how to do?
thanks!

connection timeout (no replies)

Manuel Baerten — Tue, 29 May 2012 08:05:47 +0000

Hello everybody,

is there a possibility to set a real connection timeout?

If the server machine is powered off or the IP-Adress doesn't belong
to the MySQL-server, the connection-timeout is about 20 seconds.

The MySQL-Option "MYSQL_OPT_CONNECT_TIMEOUT" is well set to 2 seconds,
but this kind of timeout isn't to handle the real connection.

Is there a possibility to avoid this problem with the libmysql?

Big thanks

what is 'thread specific variable' in MYSQL * and MYSQL_STMT * ? (no replies)

rupali gaikwad — Tue, 22 May 2012 07:04:14 +0000

Can I get any official note mentioning about above

Can't build on Windows 7 w/VS2005 (no replies)

Doug Azzarito — Wed, 28 Mar 2012 21:52:09 +0000

I have some MySQL code in C that I have been developing on Ubuntu with GCC, and I was asked for a Windows version. I have a Windows maching running Win7 64-bit, with VS2005 installed (including the 64-bit tools).

I installed the MySQL Connector/C 6.02 (the one for 64-bit VS2005), and followed the instructions for setting up a VS project for building code with it. I get a bunch of unresolved externals when I try to link (_mysql_close@4, _mysql_free_result@4, _mysql_fetch_row@4...).

I searched this forum, and saw a few posts that said building your own library sometimes helps (even though there is a release specific to my compiler width and version). I downloaded the source, and when I tried to build, I get errors like:

Cannot copy output executable '' to destination specified by COPY_FILE:

It looks like it can't find cmTryCompileExec.exe. I am using CMake version 2.8.

I found one post on this forum that suggested a way to get unresolved externals fixed, but it points to MySQL Server includes and libraries. I thought the whole reason for Connector/C is so you don't have to install MySQL Server. According to the docs, "There is no need to compile or install the MySQL Server package if you only need the client library." I installed the server on my machine to try, but it didn't solve the problem. Does anyone have a solution?

get previous versions of libmysql (1 reply)

Olag Ulga — Wed, 28 Mar 2012 07:10:42 +0000

hello

Where can i find the previous versions of libmysql? We have a application which needs 5.0.51a, but i cant find these files here: http://dev.mysql.com/downloads/connector/c/

Thanks

Olag

Problems while linking libmysqlclient_r.so (1 reply)

rupali gaikwad — Tue, 22 May 2012 07:25:26 +0000

g++ -L/usr/local/lib -L/lib/64 -L/opt/mysql/mysql/lib -L../../dependencies/glog/lib -L../../dependencies/libevent/lib -L../../dependencies/json/jsoncpp/lib -ljson-gcc-3.4.3_libmt -levent -lglog -lz -lmysqlclient_r -lpthread -lnsl -lumem -lmysys -lmystrings -o ../../dbprocess/bin/dbprocess dbprocess.o sessionlookupcsidrequest.o sessionlookupipv4request.o ../dbframework/connectionpool.o ../dbframework/connectionproxy.o ../dbframework/dbconnection.o ../framework/rpcmethod.o ../framework/rpcmethoddispatcher.o ../framework/rpcmethodfactory.o ../framework/jsonmethod.o ../framework/libeventmethoddispatcher.o ../framework/tobject.o ../framework/acceptor.o ../framework/configuefile.o ../framework/connmethoddata.o
Undefined first referenced
symbol in file
mysql_error ../dbframework/dbconnection.o
mysql_close ../dbframework/dbconnection.o
mysql_stmt_store_result sessionlookupcsidrequest.o
mysql_stmt_close ../dbframework/dbconnection.o
mysql_stmt_fetch sessionlookupcsidrequest.o
mysql_stmt_error sessionlookupcsidrequest.o
mysql_options ../dbframework/dbconnection.o
mysql_stmt_free_result sessionlookupcsidrequest.o
mysql_stmt_bind_result sessionlookupcsidrequest.o
mysql_stmt_num_rows sessionlookupcsidrequest.o
mysql_stmt_prepare ../dbframework/dbconnection.o
mysql_ping ../dbframework/dbconnection.o
mysql_init ../dbframework/dbconnection.o
mysql_stmt_bind_param sessionlookupcsidrequest.o
mysql_real_connect ../dbframework/dbconnection.o
mysql_stmt_execute sessionlookupcsidrequest.o
mysql_stmt_init ../dbframework/dbconnection.o
ld: fatal: Symbol referencing errors. No output written to ../../dbprocess/bin/dbprocess
collect2: ld returned 1 exit status

also tried ldd /opt/mysql/mysql/lib/libmysqlclient_r.so
and checked all dependencies are covered

Can prepared statement created in thread1 can be used in thread2? (2 replies)

rupali gaikwad — Wed, 16 May 2012 09:35:55 +0000

If we create prepared statement on one connection in thread1 and want to share it across thread2. is it possible? what problems I can get in case?

mysql.h not found... why not? [C] [MacOSX] (no replies)

Lynsey Schroeder — Fri, 09 Mar 2012 17:27:40 +0000

Hello,

I'm attempting to connect to my MySQL database using a C program, but it isn't making it past the #include line because it fails the compile when it can't find the header. I'm not sure why it can't find the header, I have it in the same directory as all the other headers (i.e. stdlib.h or stdio.h), which is /usr/include. I put everything from the C Connector into the include, lib, and bin folders within the usr directory.

Can anybody shed some light on this? I'm stuck.

I'm using Mac OSX Lion and xCode.

Here is my program:

#include
#include
#include

int main()
{
MYSQL *conn;
//MYSQL_RES *res;
MYSQL_ROW row;

char *server ="localhost";
char *user = "lynseysc";
char *password = "";
char *database = "lynseysc_misc";

conn = mysql_init(NULL);

if(mysql_real_connection(conn, server, user, password, database, 0, NULL, 0))
{
printf("Connected successfully!");
}
else
{
printf("Error connecting.");
}

return 0;
}

Mysql c-programming on windows, mingw (1 reply)

Leave Blank — Sat, 10 Mar 2012 14:54:20 +0000

Hello,
I am very new to Mysql programming so I made just few probes on Linux and I like it. Now, I would like to compile my programs on windows too.
For this I uses Codeblocks 10.05 IDE with GCC/MinGW compiler 4.6.1.
Wanted version of Mysql is 6.4.7 32 bit which was installed successfuly. With them I installed gui-tools and MySQL Connector C 6.0.2, all 32 bit versions.

After heavy trying to get all those to work on windows7/64 bit machine I find several posts about how to prepare libs to use it with minGW, like...

http://dev.mysql.com/doc/refman/5.0/en/building-clients.html
http://forums.mysql.com/read.php?167,295483,297733

I pexports libmysql.dll > libmysql.def, dlltool -k --input-def libmysql.def --dllname libmysql.dll --output-lib libmysql.a and just everything described with care that all my programs are 32 bit versions.

But I can't compile. Several errors appears:
||=== w_mysqlgui, Debug ===|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|24|warning: "_WIN32_WINNT" redefined [enabled by default]|
c:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.6.1\..\..\..\..\include\windef.h|20|note: this is the location of the previous definition|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|111|warning: "S_IRWXU" redefined [enabled by default]|
c:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.6.1\..\..\..\..\include\sys\stat.h|63|note: this is the location of the previous definition|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|114|error: conflicting types for 'mode_t'|
c:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.6.1\..\..\..\..\include\sys\types.h|99|note: previous declaration of 'mode_t' was here|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|177|error: conflicting types for 'ssize_t'|
c:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.6.1\..\..\..\..\include\sys\types.h|118|note: previous declaration of 'ssize_t' was here|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|235|warning: "finite" redefined [enabled by default]|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|193|note: this is the location of the previous definition|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\my_global.h|580|warning: "my_reinterpret_cast" redefined [enabled by default]|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\config-win.h|339|note: this is the location of the previous definition|
C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\my_dbug.h|98|fatal error: crtdbg.h: No such file or directory|
||=== Build finished: 9 errors, 4 warnings ===|

What do I do wrong?
Any help to start programming Mysql on windows are welcome.

libmysql won't connect to localhost but ODBC will (1 reply)

Rene Churchill — Fri, 03 Feb 2012 08:55:34 +0000

I'm pulling my hair out on this one. I've got a simple test app written two ways. One using the ODBC connector (v5.1.8) and the other with libmysql (v6.0.2).

The test app just tries to connect to the database and reports success/failure and then exits. When I'm running on Win7 Pro 64bit, the ODBC version can connect to the mysql server running on localhost but the libmysql one cannot. Both can connect to remote mysql servers (both Linux & Win7), it is just localhost that's giving me fits.

Mysqld is running on the Win7 machine, ODBC can connect to it. I can connect to it remotely from the Linux box so port 3306 is open in the windows firewall. I can connect to it via the windows command line.

Any thoughts on why libmysql can connect just fine to a remote machine but not to localhost?

Thanks,
Rene