下面讲述在Linux平台下MongoDB的C语言编程实例。
假设已经安装好了MongoDB。
1.下载MongoDB的C语言驱动并安装
这里下载的MongoDB的C语言驱动是 mongo-c-driver-1.3.5.tar.gz（https://github.com/mongodb/mongo-c-driver/releases）。
解压后打开mongo-c-driver-1.3.5目录下的 README 文件，按其中讲的方法安装，如下：
# tar xzf mongo-c-driver-1.3.5.tar.gz
# cd mongo-c-driver-1.3.5
# ./configure
# make
# sudo make install
2.启动MongoDB
# mongod
2016-07-10T11:53:20.075+0800 I CONTROL [initandlisten] MongoDB starting : pid=3071 port=27017 dbpath=/data/db 64-bit host=localhost.localdomain
2016-07-10T11:53:20.076+0800 I CONTROL [initandlisten] db version v3.2.7
2016-07-10T11:53:20.076+0800 I CONTROL [initandlisten] git version: 4249c1d2b5999ebbf1fdf3bc0e0e3b3ff5c0aaf2
...
3.编写连接MongoDB的程序 test.c
#include <bson.h>
#include <bcon.h>
#include <mongoc.h>
int
main (int argc,
char *argv[])
{
mongoc_client_t *client;
mongoc_database_t *database;
mongoc_collection_t *collection;
bson_t *command,
reply,
*insert;
bson_error_t error;
char *str;
bool retval;
/*
* Required to initialize libmongoc's internals
*/
mongoc_init ();//初始化libmongoc驱动
/*
* Create a new client instance
*/
client = mongoc_client_new ("mongodb://localhost:27017");//创建连接对象
/*
* Get a handle on the database "db_name" and collection "coll_name"
*/
database = mongoc_client_get_database (client, "db_name");//获取数据库
collection = mongoc_client_get_collection (client, "db_name", "coll_name");//获取指定数据库和集合
/*
* Do work. This example pings the database, prints the result as JSON and
* performs an insert
*/
command = BCON_NEW ("ping", BCON_INT32 (1));
retval = mongoc_client_command_simple (client, "admin", command, NULL, &reply, &error);//执行命令
if (!retval) {
fprintf (stderr, "%s\n", error.message);
return EXIT_FAILURE;
}
str = bson_as_json (&reply, NULL);
printf ("%s\n", str);
insert = BCON_NEW ("hello", BCON_UTF8 ("world"));//字段为hello，值为world字符串
if (!mongoc_collection_insert (collection, MONGOC_INSERT_NONE, insert, NULL, &error)) {//插入文档
fprintf (stderr, "%s\n", error.message);
}
bson_destroy (insert);
bson_destroy (&reply);
bson_destroy (command);
bson_free (str);
/*
* Release our handles and clean up libmongoc
*/
mongoc_collection_destroy (collection);//释放表对象
mongoc_database_destroy (database);//释放数据库对象
mongoc_client_destroy (client);//释放连接对象
mongoc_cleanup ();//释放libmongoc驱动
return 0;
}
4.编译 test.c
# gcc -o test test.c -I/usr/local/include/libmongoc-1.0 -I/usr/local/include/libbson-1.0/ -lmongoc-1.0 -lbson-1.0
# ls
test test.c
5.运行test
# ./test
{ "ok" : 1 }
连接MongoDB成功！