dbd实例

BTree读写

 Db db(NULL,DB_CXX_NO_EXCEPTIONS);//环境指针

 //事务指针,数据库类别,访问标志(创建,只读,自动提交事务,线程安全),mode在windows中忽略
 if(db.open(NULL,"test.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     cout<<"同名数据库存在"<
 }

 //基本写
 int  nKey=1;
 char szBuf[100]="愚蠢的人类啊";
 Dbt key,value;
 key.set_data(&nKey);
 key.set_size(4);
 value.set_data(szBuf);
 value.set_size(sizeof(szBuf));
 if(db.put(NULL,&key,&value,0)!=0)
 {
     cout<<"写入失败"<
 }

 //基本读
 char szBufRead[100]={0};
 Dbt readKey,readValue;
 readKey.set_data(&nKey);
 readKey.set_size(4);
 readValue.set_data(szBufRead);
 readValue.set_ulen(100);
 readValue.set_flags(DB_DBT_USERMEM);
 if(db.get(NULL,&readKey,&readValue,0)!=0)
 {
     cout<<"读取失败"<
 }

 cout<

 

Queue读写

 Db db(NULL,DB_CXX_NO_EXCEPTIONS);//环境指针

 db.set_re_len(100);
 db.set_re_pad(0);

 //事务指针,数据库类别,访问标志(创建,只读,自动提交事务,线程安全),mode在windows中忽略
 if(db.open(NULL,"DB\\test.db",NULL,DB_QUEUE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     std::cout<<"同名数据库存在"<
 }

 //基本写
 char szBuf[100]="愚蠢的人类啊";
 int nkey=0;
 Dbt key(&nkey,sizeof(nkey));
 Dbt value;
 value.set_data(szBuf);
 value.set_size(sizeof(szBuf));
 if(db.put(NULL,&key,&value,DB_APPEND)!=0)
 {
     cout<<"写入失败"<
 }
 cout<<"返回的记录号为:"<<*((int*)key.get_data())<

游标基本读写删

 Db db(NULL,DB_CXX_NO_EXCEPTIONS);//环境指针
 //事务指针,数据库类别,访问标志(创建,只读,自动提交事务,线程安全),mode在windows中忽略
 if(db.open(NULL,"test.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     cout<<"同名数据库存在"<
 }

 //基本写
 int  nKey=1;
 char szBuf[100]="愚蠢的人类啊";

 Dbt key,value;
 key.set_data(&nKey);
 key.set_size(4);
 value.set_data(szBuf);
 value.set_size(sizeof(szBuf));

 for(int i=0;i<100;++i)
 {
     nKey=i;
     if(db.put(NULL,&key,&value,0)!=0)
     {
         cout<<"写入失败"<
     }
 }

 //游标读
 Dbc *p=0;
 db.cursor(NULL,&p,0);
 Dbt key1,value1;
 while(p->get(&key1,&value1,DB_NEXT)==0)
 {
     cout<<"键:"<<(*((int *)key1.get_data()))<<"值:"<<(char*)(value1.get_data())<
 }
 //备注:游标没有函数返回当前有多少个键

 //查找
 nKey=80;
 key1.set_data(&nKey);
 key1.set_size(sizeof(int));
 p->get(&key1,&value1,DB_SET);
 p->del(0);

 //游标读
 Dbc *p1=0;
 db.cursor(NULL,&p1,0);
 while(p1->get(&key1,&value1,DB_NEXT)==0)
 {
     cout<<"键:"<<(*((int *)key1.get_data()))<<"值:"<<(char*)(value1.get_data())<
 }

数据库支持重复记录

 Db db(NULL,DB_CXX_NO_EXCEPTIONS);//环境指针

     db.set_flags(DB_DUP);

     //事务指针,数据库类别,访问标志(创建,只读,自动提交事务,线程安全),mode在windows中忽略
     if(db.open(NULL,"test.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
     {
         cout<<"同名数据库存在"<
     }

     //基本写
     int  nKey=1;
     char szBuf[100]="愚蠢的人类啊";

     Dbt key,value;
     key.set_data(&nKey);
     key.set_size(4);
     value.set_data(szBuf);
     value.set_size(sizeof(szBuf));

     for(int i=0;i<5;++i)
     {
         if(db.put(NULL,&key,&value,0)!=0)
         {
             cout<<"写入失败"<
         }
     }

     //游标读
     Dbc *p=0;
     db.cursor(NULL,&p,0);
     Dbt key1,value1;
     while(p->get(&key1,&value1,DB_NEXT)==0)
     {
         cout<<"键:"<<(*((int *)key1.get_data()))<<"值:"<<(char*)(value1.get_data())<
     }

基本环境操作

 DbEnv evn(0);
 if(evn.open("DB",DB_CREATE|DB_INIT_MPOOL,0)!=0)
 {
     cout<<"打开环境错误"<
     return 0;
 }
 Db db(&evn,DB_CXX_NO_EXCEPTIONS);//环境指针


 //事务指针,数据库类别,访问标志(创建,只读,自动提交事务,线程安全),mode在windows中忽略
 if(db.open(NULL,"test.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     cout<<"同名数据库存在"<
 }

游标的覆盖操作

 Db db(NULL,DB_CXX_NO_EXCEPTIONS);
 db.set_flags(DB_DUP);
 if(db.open(NULL,"DB\\test.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     cout<<"打开错误"<
     return 0;
 }

 int nkey=1;
 char szBuf[100]="愚蠢的地球人";
 Dbt key(&nkey,sizeof(int));
 Dbt value(szBuf,strlen(szBuf));

 for(int i=0;i<5;++i)
 {
     db.put(NULL,&key,&value,0);
 }

 Dbc *currsor=0;
 db.cursor(NULL,&currsor,0);

 Dbt key1;
 Dbt value1;
 sprintf(szBuf,"愚蠢的火星人");
 currsor->get(&key1,&value1,DB_FIRST);
 currsor->get(&key1,&value1,DB_NEXT);
 nkey=100;
 if(currsor->put(&key,&value,DB_CURRENT)!=0)
 {
     cout<<"put失败"<
 }
 currsor->get(&key1,&value1,DB_FIRST);
 cout<<*((int *)key1.get_data())<<":"<<(char*)value1.get_data()<

 while(currsor->get(&key1,&value1,DB_NEXT)==0)
 {
     cout<<*((int *)key1.get_data())<<":"<<(char*)value1.get_data()<
 }

二级数据库 没成功

 struct Info
 {
     char name[20];
     int  age;
 };

 int Fun(Db *pSecondary,const Dbt *key,const Dbt *value,Dbt *result)
 {
     //result->set_flags(DB_DBT_APPMALLOC);
     Info *p=(Info *)value->get_data();
     result->set_data((void *)(p->age));
     result->set_size(sizeof(int));
     //result->set_ulen(4);
     return 0;
 };

 int _tmain(int argc, _TCHAR* argv[])
 {
     Db dbPrimary(NULL,DB_CXX_NO_EXCEPTIONS);
     if(dbPrimary.open(NULL,"DB\\Primary.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
     {
         cout<<"打开错误"<
         return 0;
     }

     Dbt key,value;
     int nID=0;
     Info info;
     key.set_data(&nID);
     key.set_size(sizeof(int));
     value.set_data(&info);
     value.set_size(sizeof(Info));

     int nReturn=0;

     nID=100;
     sprintf(info.name,"张三");
     info.age=20;
     nReturn+=dbPrimary.put(NULL,&key,&value,0);

     nID=200;
     sprintf(info.name,"里斯");
     info.age=10;
     nReturn+=dbPrimary.put(NULL,&key,&value,0);

     nID=300;
     sprintf(info.name,"周杰伦");
     info.age=40;
     nReturn+=dbPrimary.put(NULL,&key,&value,0);

     if(nReturn!=0)
     {
         cout<<"出错啦"<
         return 0;
     }


     Db dbSecondary(NULL,DB_CXX_NO_EXCEPTIONS);
     if(dbSecondary.open(NULL,"DB\\Secondary.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
     {
         cout<<"打开错误"<
         return 0;
     }

     if(dbPrimary.associate(NULL,&dbSecondary,Fun,DB_CREATE)!=0)
     {
         cout<<"associate错误"<
         return 0;
     }


     /*Dbc *pCursor=0;
     if(dbSecondary.cursor(NULL,&pCursor,0)!=0)
     {
         cout<<"cursor创建错误"<
         return 0;
     }
     */
     nID=100;
     if(dbSecondary.get(NULL,&key,&value,0)==0)
     {
         cout<<((Info *)value.get_data())->name<
     }


     /*Dbt key1;
     Dbt value1;

     nID=20;
     if(pCursor->get(&key1,&value1,DB_FIRST|DB_GET_BOTH)!=0)
     {
         if(pCursor->get(&key1,&value1,DB_FIRST)==DB_NOTFOUND)
             cout<<"没有元素"<
         cout<<"get错误"<
         return 0;
     }
     cout<<*((int *)key1.get_data())<<":"<<((Info *)value1.get_data())->name<
     while(pCursor->get(&key1,&value1,DB_NEXT)!=0)
     {
         cout<<*((int *)key1.get_data())<<":"<<(char *)value1.get_data()<
     }*/

     return 0;
 }

部分写

 Db dbPrimary(NULL,DB_CXX_NO_EXCEPTIONS);
 if(dbPrimary.open(NULL,"DB\\Primary.db",NULL,DB_BTREE,DB_CREATE|DB_TRUNCATE,0)!=0)
 {
     cout<<"打开错误"<
     return 0;
 }

 Dbt key,value;
 int nID=0;
 Info info;
 key.set_data(&nID);
 key.set_size(sizeof(int));
 value.set_data(&info);
 value.set_size(sizeof(Info));

 int nReturn=0;

 nID=100;
 sprintf(info.name,"张三");
 info.age=20;
 nReturn+=dbPrimary.put(NULL,&key,&value,0);

 nID=200;
 sprintf(info.name,"里斯");
 info.age=10;
 nReturn+=dbPrimary.put(NULL,&key,&value,0);

 nID=300;
 sprintf(info.name,"周杰伦");
 info.age=40;
 nReturn+=dbPrimary.put(NULL,&key,&value,0);

 if(nReturn!=0)
 {
     cout<<"出错啦"<
     return 0;
 }

 nID=200;
 char name[20]={"四"};
 Dbt bt;
 bt.set_flags(DB_DBT_PARTIAL);
 bt.set_data(name);
 bt.set_size(20);
 bt.set_doff(0);
 bt.set_dlen(20);
 if(dbPrimary.put(NULL,&key,&bt,NULL)==0)
 {
     cout<<"成功"<

     Dbc *pCursor=0;
     dbPrimary.cursor(NULL,&pCursor,0);

     Dbt key1,value1;
     while(pCursor->get(&key1,&value1,DB_NEXT)==0)
     {
         cout<<*((int *)(key1.get_data()))<<":"<<((Info *)(value1.get_data()))->name<<":"<<((Info *)(value1.get_data()))->age<
     }
 }

事务

 DbEnv env(0);
 env.set_data_dir("Database");
 env.set_lg_dir("Log");
 //日志系统木默认是开启的
 env.open("Environment",DB_CREATE|DB_INIT_MPOOL|DB_INIT_TXN|DB_INIT_LOCK|DB_PRIVATE,0);

 Db dbPrimary(&env,DB_CXX_NO_EXCEPTIONS);

 DbTxn *pTxn;
 env.txn_begin(NULL,&pTxn,0);
 if(dbPrimary.open(pTxn,"Primary.db",NULL,DB_BTREE,DB_CREATE,0)!=0)
 {
     cout<<"打开错误"<
     return 0;
 }
 pTxn->commit(0);

 Dbt key,value;
 int nID=0;
 Info info;
 key.set_data(&nID);
 key.set_size(sizeof(int));
 value.set_data(&info);
 value.set_size(sizeof(Info));

 int nReturn=0;

 nID=100;
 sprintf(info.name,"张三");
 info.age=20;

 nReturn+=dbPrimary.put(NULL,&key,&value,0);


 nID=200;
 sprintf(info.name,"里斯");
 info.age=10;

 int ntime1=timeGetTime();

 for(int i=0;i<1000000;++i)
 {
     nID+=1;
     env.txn_begin(NULL,&pTxn,0);
     dbPrimary.put(pTxn,&key,&value,0);
     pTxn->abort();
 }
 int ntime2=timeGetTime();
 cout<

 env.txn_begin(NULL,&pTxn,0);
 nID=300;
 sprintf(info.name,"周杰伦");
 info.age=40;
 nReturn+=dbPrimary.put(pTxn,&key,&value,0);
 pTxn->abort();

 if(nReturn!=0)
 {
     cout<<"出错啦"<
     return 0;
 }

 Dbc *pCursor=0;
 dbPrimary.cursor(NULL,&pCursor,0);

 Dbt key1,value1;
 while(pCursor->get(&key1,&value1,DB_NEXT)==0)
 {
     cout<<*((int *)(key1.get_data()))<<":"<<((Info *)(value1.get_data()))->name<<":"<<((Info *)(value1.get_data()))->age<
 }

最终方案

 DbEnv env(0);
 env.set_data_dir("Database");
 env.set_lg_dir("Log");

 env.set_cachesize(0,500*1024*1024,0);
 env.log_set_config(DB_TXN_NOSYNC,1);
 env.set_lg_bsize(300*1024*1024);


 //日志系统木默认是开启的
 env.open("Environment",DB_CREATE|DB_INIT_MPOOL|DB_INIT_TXN|DB_INIT_LOCK|DB_PRIVATE|DB_RECOVER,0);

 //打开数据库
 Db dbPrimary(&env,DB_CXX_NO_EXCEPTIONS);
 DbTxn *pTxn;
 env.txn_begin(NULL,&pTxn,0);
 if(dbPrimary.open(pTxn,"Primary.db",NULL,DB_BTREE,DB_CREATE,0)!=0)
 {
     cout<<"打开错误"<
     return 0;
 }
 pTxn->commit(0);

 Dbt key,value;
 int nID=0;
 Info info;
 key.set_data(&nID);
 key.set_size(sizeof(int));
 value.set_data(&info);
 value.set_size(sizeof(Info));

 nID=200;
 sprintf(info.name,"里斯");
 info.age=10;

 int ntime1=timeGetTime();
 env.txn_begin(NULL,&pTxn,0);
 for(int i=0;i<20000;++i)
 {
     nID+=1;
     dbPrimary.put(pTxn,&key,&value,0);
 }
 pTxn->commit(0);
 int ntime2=timeGetTime();
 cout<<(ntime2-ntime1)/1000<
 system("pause");

一些配置

 DbEnv env(0);
     env.set_data_dir("Database");
     env.set_lg_dir("Log");

     env.set_cachesize(0,500*1024*1024,0);
     env.log_set_config(DB_TXN_NOSYNC,1);
     env.set_lg_bsize(300*1024*1024);
     //db_env->set_lg_max()

     //日志系统木默认是开启的
     env.open("Environment",DB_CREATE|DB_INIT_MPOOL|DB_INIT_TXN|DB_INIT_LOCK|DB_PRIVATE|DB_RECOVER,0);
     env.set_flags(DB_HOTBACKUP_IN_PROGRESS,1);
     env.txn_checkpoint(0,0,DB_FORCE);
     env.log_archive(NULL,DB_ARCH_REMOVE);
     env.log_set_config(DB_LOG_AUTO_REMOVE,1);
     env.txn_checkpoint(0,0,DB_FORCE);

复制

 //Master
 DbEnv env(0);
 env.set_data_dir("Database");
 env.set_lg_dir("Log");

 env.set_cachesize(0,300*1024*1024,0);
 env.log_set_config(DB_TXN_NOSYNC,1);
 env.set_lg_bsize(300*1024*1024);
 //db_env->set_lg_max()


 DbSite *p;
 env.repmgr_site("192.168.1.182",6000,&p,0);
 p->set_config(DB_LOCAL_SITE,1);
 p->set_config(DB_GROUP_CREATOR,1);
 p->close();
 env.rep_set_priority(100);
 env.repmgr_set_ack_policy(DB_REPMGR_ACKS_NONE);

 env.open("Environment",DB_CREATE|DB_INIT_MPOOL|DB_INIT_TXN|DB_INIT_LOCK|DB_PRIVATE|DB_RECOVER|DB_INIT_REP|DB_THREAD,0);
 env.set_flags(DB_HOTBACKUP_IN_PROGRESS,1);

 env.repmgr_start(3,DB_REP_MASTER);

 //打开数据库
 Db dbPrimary(&env,DB_CXX_NO_EXCEPTIONS);
 DbTxn *pTxn;
 env.txn_begin(NULL,&pTxn,0);
 if(dbPrimary.open(pTxn,"Primary.db",NULL,DB_BTREE,DB_CREATE,0)!=0)
 {
     cout<<"打开错误"<
     return 0;
 }
 pTxn->commit(0);

 Dbt key,value;
 int nID=0;
 Info info;
 key.set_data(&nID);
 key.set_size(sizeof(int));
 value.set_data(&info);
 value.set_size(sizeof(Info));

 nID=100;
 sprintf(info.name,"里斯");
 info.age=10;

 int ntime1=timeGetTime();
 for(int j=0;j<10000;++j)
 {
     for(int i=0;i<10000;++i)
     {
         env.txn_begin(NULL,&pTxn,0);
         nID+=1;
         dbPrimary.put(pTxn,&key,&value,0);
         pTxn->commit(0);
     }
     cout<<"插入"<
 }
 int ntime2=timeGetTime();
 cout<<(ntime2-ntime1)/1000<

 Dbc *pCursor=0;
 dbPrimary.cursor(NULL,&pCursor,0);
 Dbt key1,value1;

 pCursor->get(&key1,&value1,DB_LAST);
 cout<<*((int *)(key1.get_data()))<<":"<<((Info *)(value1.get_data()))->name<<":"<<((Info *)(value1.get_data()))->age<

 /*while(pCursor->get(&key1,&value1,DB_NEXT)==0)
 {
     cout<<*((int *)(key1.get_data()))<<":"<<((Info *)(value1.get_data()))->name<<":"<<((Info *)(value1.get_data()))->age<
 }*/

 //end Master---------------------------------------------


 //参与者
 DbEnv env(0);

 env.set_data_dir("Database");
 env.set_lg_dir("Log");

 env.set_cachesize(0,300*1024*1024,0);
 env.log_set_config(DB_TXN_NOSYNC,1);
 env.set_lg_bsize(300*1024*1024);


 DbSite *p;
 env.repmgr_site("127.0.0.1",5000,&p,0);
 p->set_config(DB_LOCAL_SITE,1);
 p->close();
 env.rep_set_priority(100);

 DbSite *pOther;
 env.repmgr_site("192.168.1.182",6000,&pOther,0);
 pOther->set_config(DB_BOOTSTRAP_HELPER,1);
 pOther->close();

 env.open("Environment",DB_CREATE|DB_INIT_MPOOL|DB_INIT_TXN|DB_INIT_LOCK|DB_PRIVATE|DB_RECOVER|DB_INIT_REP|DB_THREAD,0);
 env.set_flags(DB_HOTBACKUP_IN_PROGRESS,1);

 int a=env.repmgr_start(3,DB_REP_CLIENT);

 while(true)
 {
     Sleep(1000);
 }