undefined reference to `mysql_init'解決辦法

寫了一個很簡單的測試數據庫連接的程序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編譯:gcc -o conn conn.c出現如下錯誤:
/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
出現該錯誤的原因是因為編譯器找不到mysql_init,mysql_close等的具體實現.雖然我們包括了正確的頭文件,但是 我們在編譯的時候還是要連接確定的庫.對於一些常用的函數的實現,gcc編譯器會自動去連接一些常用庫,這樣我們就沒有必要自己去指定了,如:printf函數.在本程序中要通過-L選項包含庫文件的路徑:
gcc -o conn conn.c -L /usr/local/mysql/lib/*.a -lz
通過,用*.a將庫全部包含進來拉,其實只要包含mysqlclient.a就可以. -lz什么意思我也不清楚了

 

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加 -lmysqlclient