var
MongcClient
= require(
'mongodb'
).MongoClient;
var
express
= require(
"express"
);
var
app
=
express
();
var
assert
= require(
"assert"
);
function
_connectDB
(callback){
var
url
=
'mongodb://localhost:27017/test'
;
//连接数据库
MongcClient
.
connect
(
url
,
function
(err,db) {
callback(err,db);
})
};
//插入数据
exports
.
insertOne
=
function
(collectionName,json,callback){
_connectDB
(
function
(err,db){
db.
collection
(collectionName).
insertOne
(json,
function
(err,result) {
callback(err,result);
db.
close
();
})
});
};
//查找数据
exports
.
find
=
function
(collectionName,json,args,callback) {
var
result
=[];
if
(
arguments
.
length
!=
4
){
callback(
"find函数接收4个参数"
,
null
);
return
;
}
//应该省略的条数
var
skipnumber
= args.
pageamount
* args.
page
||
0
;
//limit的数量
var
limit
= args.
pageamount
;
_connectDB
(
function
(err,db) {
var
cursor
= db.
collection
(collectionName).
find
(json).skip(
skipnumber
).limit(
limit
);
cursor
.each(
function
(err,doc) {
assert
.equal(err,
null
);
if
(err){
callback(err,
null
);
return
;
}
if
(doc !=
null
){
result
.
push
(doc);
//放入结果数组
}
else
{
//遍历结束，没有更多的文档了
callback(
null
,
result
);
}
})
})
};
//删除
exports
.
deleteMany
=
function
(collectionName,json,callback) {
_connectDB
(
function
(err, db) {
db.
collection
(collectionName).
deleteMany
(
json,
function
(err, results) {
callback(err, results);
db.
close
();
//关闭数据库
}
);
});
};
//修改
exports
.
updateMany
=
function
(collectionName, json1, json2, callback) {
_connectDB
(
function
(err, db) {
db.
collection
(collectionName).
updateMany
(
json1,
json2,
function
(err, results) {
callback(err, results);
db.
close
();
});
})
};
//获取留言总数
exports
.
getAllCount
=
function
(collectionName,callback) {
_connectDB
(
function
(err, db) {
db.
collection
(collectionName).
count
({}).then(
function
(count) {
callback(count);
db.
close
();
});
})
};