undefined reference to `mysql_init'解决办法

写了一个很简单的测试数据库连接的程序conn.c如下:
#include <stdio.h>
#include <stdlib.h>
#include "/usr/local/mysql/include/mysql/mysql.h"
#include <string.h>
int main(int argc, char *argv[])
{
MYSQL my_connection;
mysql_init(&my_connection);
if (mysql_real_connect(&my_connection, "localhost", "root", "","mysql",0,NULL,CLIENT_FOUND_ROWS))
{
    printf("Connection success\n"); 
    mysql_close(&my_connection);
}
else
{
    fprintf(stderr, "Connection failed\n");
    if (mysql_errno(&my_connection))
    {
        fprintf(stderr, "Connection error %d: %s\n",mysql_errno(&my_connection),mysql_error(&my_connection));
        }
}
    return EXIT_SUCCESS;
}
gcc编译:gcc -o conn conn.c出现如下错误:
/tmp/ccY0JTdh.o(.text+0x1e): In function `main':
: undefined reference to `mysql_init'
/tmp/ccY0JTdh.o(.text+0x47): In function `main':
: undefined reference to `mysql_real_connect'
/tmp/ccY0JTdh.o(.text+0x6d): In function `main':
: undefined reference to `mysql_close'
/tmp/ccY0JTdh.o(.text+0x97): In function `main':
: undefined reference to `mysql_errno'
/tmp/ccY0JTdh.o(.text+0xad): In function `main':
: undefined reference to `mysql_error'
/tmp/ccY0JTdh.o(.text+0xc0): In function `main':
: undefined reference to `mysql_errno'
collect2: ld returned 1 exit status
出现该错误的原因是因为编译器找不到mysql_init,mysql_close等的具体实现.虽然我们包括了正确的头文件,但是 我们在编译的时候还是要连接确定的库.对于一些常用的函数的实现,gcc编译器会自动去连接一些常用库,这样我们就没有必要自己去指定了,如:printf函数.在本程序中要通过-L选项包含库文件的路径:
gcc -o conn conn.c -L /usr/local/mysql/lib/*.a -lz
通过,
用*.a将库全部包含进来拉,其实只要包含mysqlclient.a就可以. -lz什么意思我也不清楚了

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

加 -lmysqlclient

原文地址:https://www.cnblogs.com/rooney/p/3003138.html