linux MYSQL 编程

在linux里面安装了通过mysql     :yum install mysql-server 

安装完成后，在编程编译时发现找不到对应mysql.h头文件。

 gcc -o mysql mysql.c 
mysql.c:2:21: error: mysql.h: No such file or directory
mysql.c: In function ‘main’:
mysql.c:6: error: ‘MYSQL’ undeclared (first use in this function)
mysql.c:6: error: (Each undeclared identifier is reported only once
mysql.c:6: error: for each function it appears in.)
mysql.c:6: error: expected ‘;’ before ‘mysql’
mysql.c:8: error: ‘mysql’ undeclared (first use in this function)

此时我们只要在安装一下：yum install mysql-devel 就可以在usr/include/mysql里面找到mysql.h文件了，

继续编译mysql 程序时出现如下错误：

zdg@localhost myproject]$ gcc -o mysql mysql.c  -I /usr/include/mysql/
/tmp/cc5glykp.o: In function `main':
mysql.c:(.text+0x23): undefined reference to `mysql_init'
mysql.c:(.text+0x37): undefined reference to `mysql_error'
mysql.c:(.text+0x94): undefined reference to `mysql_real_connect'
mysql.c:(.text+0xa8): undefined reference to `mysql_error'
mysql.c:(.text+0xe0): undefined reference to `mysql_close'
collect2: ld returned 1 exit status

没有指定mysql 编译需要链接到的库文件，可以使用如下命令查看对应mysql 配置路径：

mysql_config

[zdg@localhost myproject]$ 
[zdg@localhost myproject]$ mysql_config
Usage: /usr/lib64/mysql/mysql_config [OPTIONS]
Options:
        --cflags         [-I/usr/include/mysql  -g -pipe -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fwrapv -fPIC   -DUNIV_LINUX -DUNIV_LINUX]
        --include        [-I/usr/include/mysql]
        --libs           [-rdynamic -L/usr/lib64/mysql -lmysqlclient -lz -lcrypt -lnsl -lm -lssl -lcrypto]
        --libs_r         [-rdynamic -L/usr/lib64/mysql -lmysqlclient_r -lz -lpthread -lcrypt -lnsl -lm -lpthread -lssl -lcrypto]
        --plugindir      [/usr/lib64/mysql/plugin]
        --socket         [/var/lib/mysql/mysql.sock]
        --port           [0]
        --version        [5.1.73]
        --libmysqld-libs [-rdynamic -L/usr/lib64/mysql -lmysqld -ldl -lz -lpthread -lcrypt -lnsl -lm -lpthread -lrt -lssl -lcrypto]
[zdg@localhost myproject]$ 

接下来编译时指定mysql 对应头文件和库文件即可：

gcc -o mysql mysql.c  -I /usr/include/mysql/ -L /usr/lib64/mysql/ -lmysqlclient

编译成功，附上测试源码：

#include   
#include   
   
int main(int argc, const char *argv[])  
{  
    MYSQL   mysql;  
   
    if (NULL == mysql_init(&mysql)) {    //为数据库分配和初始化MYSQL对象  
        printf("mysql_init(): %s\n", mysql_error(&mysql));  
        return -1;  
    }  
   
    //尝试与运行在主机上的MySQL数据库引擎建立连接  
    if (NULL == mysql_real_connect(&mysql,  
                "localhost",  
                "root",  
                "12345",  
                "db_users",  
                0,  
                NULL,  
                0)) {  
        printf("mysql_real_connect(): %s\n", mysql_error(&mysql));  
        return -1;  
    }  
   
    printf("Connected MySQL successful! \n");  
   
    mysql_close(&mysql);  
    return 0;  
}