MongoDB学习笔记【3】-- MongoDB C驱动使用

深藏阁楼爱情的钟 2021-11-02 03:22 363阅读 0赞

[MongoDB官方手册：http://docs.mongodb.org/ecosystem/drivers/c/][MongoDB_http_docs.mongodb.org_ecosystem_drivers_c]

下载mongodb C driver

[root@slayer ~]# git clone git://github.com/mongodb/mongo-c-driver.git

编译，安装

#cd mongo-c-driver
    #make && make install

从官方手册找个demo mongo\_c.c

#include <stdio.h>
    #include <mongo.h>
    
    int main()
    {
       mongo conn[1];
       int status = mongo_client( conn, "127.0.0.1", 27017 );
    
       if( status != MONGO_OK ) {
          switch ( conn->err ) {
             case MONGO_CONN_NO_SOCKET:
                 printf( "no socket\n" );
                 return 1;
             case MONGO_CONN_FAIL:
                 printf( "connection failed\n" );
                 return 1;
             case MONGO_CONN_NOT_MASTER:
                 printf( "not master\n" );
                 return 1;
          }
       }
       printf( "connection done\n");
    
       mongo_destroy( conn );
    
       return 0;
    }

编译，运行

[root@slayer mongo-c-driver]# gcc -lmongoc --std=c99 mongo_c.c -o mongo_c
    [root@slayer mongo-c-driver]# ./mongo_c
    ./mongo_c: error while loading shared libraries: libmongoc.so.0.7: cannot open shar
    ed object file: No such file or directory

找不到动态库，找找libmongoc.so.0.7在哪

[root@slayer mongo-c-driver]# find / -name libmongoc.so.0.7
    /usr/local/lib/libmongoc.so.0.7

看看ld路径

[root@slayer mongo-c-driver]# cat /etc/ld.so.conf
    include ld.so.conf.d/*.conf
    [root@slayer mongo-c-driver]# cat /etc/ld.so.conf.d/*
    /usr/lib64/mysql
    /usr/lib/xulrunner-2
    /usr/lib64/xulrunner-2

果然没有/usr/local/lib，把它加上试试

[root@slayer mongo-c-driver]# echo /usr/local/lib/ > /etc/ld.so.conf.d/mongoc.conf
    [root@slayer mongo-c-driver]# ldconfig
    [root@slayer mongo-c-driver]# !gcc
    gcc -lmongoc --std=c99 mongo_c.c -o mongo_c
    [root@slayer mongo-c-driver]# ./mongo_c
    connection done
    [root@slayer mongo-c-driver]#

连接成功

简单插入和查询 mongo\_c\_wr.c

#include <stdlib.h>
    #include <stdio.h>
    #include <mongo.h>
    
    static void tutorial_insert_batch( mongo *conn ) {
      bson *p, **ps;
      char *names[4];
      int ages[] = { 29, 24, 24, 32 };
      int i, n = 4;
      names[0] = "Eliot"; names[1] = "Mike"; names[2] = "Mathias"; names[3] = "Richard";
    
      ps = ( bson ** )malloc( sizeof( bson * ) * n);
    
      for ( i = 0; i < n; i++ ) {
        p = ( bson * )malloc( sizeof( bson ) );
        bson_init( p );
        bson_append_new_oid( p, "_id" );
        bson_append_string( p, "name", names[i] );
        bson_append_int( p, "age", ages[i] );
        bson_finish( p );
        ps[i] = p;
      }
    
      mongo_insert_batch( conn, "mydb.fc", ps, n, NULL, 0 );
    
      for ( i = 0; i < n; i++ ) {
        bson_destroy( ps[i] );
        free( ps[i] );
      }
    }
    
    /*
     * ===  FUNCTION  ======================================================================
     *         Name:  main
     *  Description:
     * =====================================================================================
     */
       int
    main ( int argc, char *argv[] )
    {
       mongo conn[1];
       int status = mongo_client( conn, "127.0.0.1", 27017 );
    
       if( status != MONGO_OK ) {
          switch ( conn->err ) {
             case MONGO_CONN_NO_SOCKET:  printf( "no socket\n" ); return 1;
             case MONGO_CONN_FAIL:       printf( "connection failed\n" ); return 1;
             case MONGO_CONN_NOT_MASTER: printf( "not master\n" ); return 1;
          }
       }
       printf( "connection done\n" );
    
    
       /* make bson object */
       bson *b = (bson*) malloc(sizeof(bson));
       bson_init( b );
       bson_append_string( b, "name", "Joe" );
       bson_append_int( b, "age", 33);
       bson_finish( b );
    
       bson_print(b);
    
       /* insert bson object */
       mongo_insert( conn, "mydb.fc", b, NULL);
    
       /* destroy Joe */
       bson_destroy( b );
       free(b);
    
       /* batch insert */
       tutorial_insert_batch(conn);
    
    
       /* query */
       bson query[1];
       mongo_cursor  cursor[1];
       mongo_cursor_init( cursor, conn, "mydb.fc" );
    
       /* query from database */
       while (mongo_cursor_next(cursor) == MONGO_OK)
          bson_print(&cursor->current);
    
       mongo_cursor_destroy(cursor);
    
       mongo_destroy( conn );
    
       return EXIT_SUCCESS;
    
    }           /* ----------  end of function main  ---------- */

编译运行

[root@slayer mongo-c-driver]# gcc --std=c99  -lmongoc -lbson mongo_c_wr.c -o mcwr
    mongo_c_wr.c: In function 'tutorial_insert_batch':
    mongo_c_wr.c:24: warning: passing argument 3 of 'mongo_insert_batch' from incompatible pointer type
    [root@postgresql mongo-c-driver]# ./mcwr
    connection done
            name : 2         Joe
            age : 16         33
            _id : 7          50c99a05c0ac94782d63d5a1
            name : 2         Joe
            age : 16         33
            _id : 7          50c99a05c8730a6b00000000
            name : 2         Eliot
            age : 16         29
            _id : 7          50c99a05c8730a6b00000001
            name : 2         Mike
            age : 16         24
            _id : 7          50c99a05c8730a6b00000002
            name : 2         Mathias
            age : 16         24
            _id : 7          50c99a05c8730a6b00000003
            name : 2         Richard
            age : 16         32

[MongoDB学习笔记【1】-- 安装启动][MongoDB_1_--]

[MongoDB学习笔记【2】-- 试用][MongoDB_2_--]

[MongoDB学习笔记【3】-- MongoDB C驱动使用][MongoDB_3_-- MongoDB C]

[MongoDB学习笔记【4】-- MongoDB Java驱动使用][MongoDB_4_-- MongoDB Java]

转载于:https://www.cnblogs.com/Leo-Forest/archive/2013/03/01/2938704.html

[MongoDB_http_docs.mongodb.org_ecosystem_drivers_c]: http://docs.mongodb.org/ecosystem/drivers/c/
[MongoDB_1_--]: http://www.cnblogs.com/leo-forest/archive/2013/03/01/2938256.html
[MongoDB_2_--]: http://www.cnblogs.com/leo-forest/archive/2013/03/01/2938364.html
[MongoDB_3_-- MongoDB C]: http://www.cnblogs.com/leo-forest/archive/2013/03/01/2938704.html
[MongoDB_4_-- MongoDB Java]: http://www.cnblogs.com/Leo-Forest/archive/2013/03/04/2942424.html