详解MongoDB数据库基础操作及实例

详解数据库基础操作及实例

          废话不多说，直接上代码，注释写的比较清楚，大家参考下，

 示例代码：

/** 
 * 插入一条db对象 
 */ 
public static void adddbobject(dbcollection collection,basicdbobject object){ 
  collection.insert(object); 
} 
 
/** 
 * 根据id查询dbobject 
 */ 
public static dbobject getdbobjectbyid(string value) throws unknownhostexception, mongoexception{ 
  dbc = getdbcollection("company", "users").find(new basicdbobject("_id",new objectid(value))); 
  dbobject ob = null; 
  int i = 0; 
  while(dbc.hasnext()){ 
    ob = dbc.next(); 
    i++; 
  } 
  if(i == 1){ 
    return ob; 
  }else{ 
    return null; 
  } 
} 
 
/** 
 * 根据key和value值查询 
 */ 
public static dbobject getdbobject(string key,string value) throws unknownhostexception, mongoexception{ 
  dbc = getdbcollection("company", "users").find(new basicdbobject(key,value)); 
  dbobject ob = null; 
  int i = 0; 
  while(dbc.hasnext()){ 
    ob = dbc.next(); 
    i++; 
  } 
  if(i == 1){ 
    return ob; 
  }else{ 
    return null; 
  } 
} 
 
/** 
 * 根据数据库名获取(新增)下面所有聚集名（表名） 
 */ 
public static set<string> getcollectionsnames(string dbname) throws mongoexception, unknownhostexception{ 
  return getdb(dbname).getcollectionnames(); 
} 
 
/** 
 * 遍历聚集中的db对象集合(相当于关系数据库中的数据) 
 */ 
public static set<dbobject> getdbobjects(dbcollection collection){ 
  set<dbobject> dbobjects = new hashset<dbobject>(); 
  dbcursor cursor = collection.find(); 
  while(cursor.hasnext()){ 
    dbobject object = cursor.next(); 
    dbobjects.add(object); 
  } 
  return dbobjects; 
} 
 
/** 
 * 获取/新增聚集（相当于关系数据库表） 
 */ 
public static dbcollection getdbcollection(string dbname,string collectionname) throws unknownhostexception, mongoexception{ 
  return getdb(dbname).getcollection(collectionname); 
} 
 
/** 
 * 获取/新增数据库 
 */ 
public static db getdb(string dbname) throws unknownhostexception, mongoexception{ 
  return getmongo().getdb(dbname); 
} 
 
/** 
 * 连接数据库 
 */ 
public static mongo getmongo() throws unknownhostexception, mongoexception{ 
  mongo mg = null; 
  if(mg == null){ 
    mg = new mongo(); 
  } 
  return mg; 
} 
 
/** 
 * 关闭连接 
 */ 
public static void destory(mongo mg) { 
  if (mg != null){ 
    mg.close(); 
    mg = null;  
  } 
  system.gc();   
} 
 
/** 
 * 获取数据库名 
 */ 
public static list<string> getdbnames() throws mongoexception, unknownhostexception{ 
  return getmongo().getdatabasenames(); 
} 
 
/** 
 * 删除数据库 
 */ 
public static void deletedb(string dbname) throws mongoexception, unknownhostexception{ 
  getmongo().dropdatabase(dbname); 
} 

如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！