在MAC OSX上编译简单的mysql c应用程序时，为什么为什么总是得到未定义的符号? [英] Why do I keep getting undefined symbols when compiling a simple mysql c application on MAC OSX?

问题描述

我正在使用MAC OSX并试图编写一个测试" msyql应用程序，该应用程序仅测试与本地数据库的连接:

I'm using MAC OSX and trying to write a 'test' msyql app that just tests the connection to a local database:

#include <my_global.h>
#include <mysql.h>


int main(void)
{
    MYSQL mysql;

    mysql_init(&mysql);
    mysql_options(&mysql, MYSQL_READ_DEFAULT_GROUP, "examplemysql");
    if(!mysql_real_connect(&mysql, "localhost", "someuser", "somepassword", "sampledb", 0, NULL, 0))
    {
        fprintf(stderr, "Failed to connect to database: Error: %s\n", mysql_error(&mysql));
    }

}

我使用以下命令进行编译:gcc -I/usr/local/mysql/include -L/usr/local/mysql/lib mysql.c

I compile using the command: gcc -I/usr/local/mysql/include -L/usr/local/mysql/lib mysql.c

我遇到以下错误

未定义符号
"_mysql_options"，引用自: _main in cceohP7E.o
"_mysql_real_connect"，引用自: _main in cceohP7E.o
"_mysql_init"，引用自: _main in cceohP7E.o
"_mysql_error"，引用自: _main in cceohP7E.o
ld:找不到符号
collect2:ld返回1退出状态

Undefined symbols
"_mysql_options", referenced from:
_main in cceohP7E.o
"_mysql_real_connect", referenced from:
_main in cceohP7E.o
"_mysql_init", referenced from:
_main in cceohP7E.o
"_mysql_error", referenced from:
_main in cceohP7E.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

我不是C/Unix专家，但我想学习.我知道我在这里运行64位体系结构.这会是一个问题吗?让我知道我在做什么错.

I'm no C/Unix expert, but I want to learn. I know I have a 64-bit architecture running here. Can this be an issue? Let me know what I'm doing wrong.

谢谢.

推荐答案

正如其他人所提到的，您缺少该库.幸运的是，MySQL通过命令行的mysql_config:

As the others have mentioned, you're missing the library. Fortunately, MySQL makes this easy via the command line's mysql_config:

gcc `mysql_config --include` mysql.c `mysql_config --libs`

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