main.c

程序代码使用说明： (1)所有源代码目录下都提供了Makefile（非Qt）

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* To use bdb, include this header file.*/
#include <db.h>   

#define DB_FILE "test_data.db"


int main()
{
    DB_ENV *myEnv;
    DB *dbp;
    DBT key, data;
    int ret,t_ret;
    u_int32_t env_flags;      /* env open flags */

    /* 
        Create an environment object and initialize it for error
        reporting. 
    */
    ret = db_env_create(&myEnv, 0);
    if (ret != 0) 
    {
        printf("Error creating env handle: %s\n", db_strerror(ret));
        return -1;
    }

    /* Open the environment. */
    env_flags = DB_CREATE |    /* If the environment does not exist, create it. */
                DB_INIT_MPOOL; /* Initialize the in-memory cache. */
    
    ret = myEnv->open(myEnv,         /* DB_ENV ptr */
            "/tmp/db/testEnv",      /* env home directory */
            env_flags,              /* Open flags */
            0);                     /* File mode (default) */
    if (ret != 0) 
    {
        printf("Environment open failed: %s\n", db_strerror(ret));
        return -1;
    } 
 

    /* create database*/
    if ((ret = db_create(&dbp, myEnv, 0)) != 0)
    {
          printf("db_create: %s\n", db_strerror(ret));
          return -1;
    }

    if ((ret = dbp->open(dbp, NULL, DB_FILE, NULL, DB_BTREE, DB_CREATE, 0664)) != 0)
    {
          dbp->err(dbp, ret, "%s", DB_FILE);
          return -1;
    }
    
    char* name = "Bill"; 
    int height = 175;
    
    memset(&key, 0, sizeof(key));
    memset(&data, 0, sizeof(data)); 
    
    key.data = name;
    key.size = strlen(name) + 1;
    data.data = &height;
    data.size = sizeof(int);

    /* put data, NO-OVERWRITE */
    if ((ret = dbp->put(dbp, NULL, &key, &data, DB_NOOVERWRITE)) == 0)
        printf("bdb -- key: %s and data: %d stored.\n", (char *)key.data, *((int *)data.data));
    else 
        dbp->err(dbp, ret, "bdb -- put error");

    /* get data */
    DBT ret_key, ret_data;
    memset(&ret_key, 0, sizeof(&ret_key));
    memset(&ret_data, 0, sizeof(&ret_data));
    
    ret_key.data = name;
    ret_key.size = strlen(name) + 1;
    ret_key.flags = DB_DBT_USERMEM;
    
    int h = 0;
    ret_data.data = &h;
    ret_data.ulen = sizeof(int);
    ret_data.flags = DB_DBT_USERMEM;
  
    if ((ret = dbp->get(dbp, NULL, &ret_key, &ret_data, 0)) == 0)
    {
        printf("bdb -- key: %s retrieved; data was %d.\n", (char *)ret_key.data, h);
    }
    else
        dbp->err(dbp, ret, "bdb -- get record error");

    /* delelte record */
    if((ret = dbp->del(dbp, NULL, &key, 0)) == 0)
        printf("bdb -- key %s was deleted.\n", (char *)key.data);
    else
        dbp->err(dbp, ret, "bdb -- delelte db error");

    /* close, only when the db successful closed,the data can real write to the disk. */
    if (dbp != NULL)
        dbp->close(dbp, 0);
    /* Close evn
     * When you are done with an environment, you must close it.
     * Before you close an environment, make sure you close any opened databases */
    if (myEnv != NULL)
        myEnv->close(myEnv, 0);

    return 0;
}