node. JS Query Statement Encapsulation

/**
* Created by Administrator on 2017/3/3 0003.
*/
var mongo=require (' MongoDB ');

var config=require ("./config.js"). Config;

var mongoclient=mongo.mongoclient;

var Objectid=mongo.objectid;

/* Connect to Database */
function _connectdb (callback) {
Mongoclient.connect (Config.dburl,function (err,db) {
if (err) {
Console.log (' Database connection failed ... ');
Callback (err, NULL);
Return
//    }
Callback (err, DB);
//})

Mongoclient.connect (Config.dburl,function (err,db) {

if (err) {
Console.log (' Database connection failed ... ');
Callback (err, NULL);
Return
}
Callback (err, DB);
})

}





Used to get ID
Exports. Objectid=objectid;

Exports.count=function (Collectionname,json,callback) {


_connectdb (function (err,db) {
Db.collection (CollectionName). Count (JSON, function (err, result) {
Callback (err, result);
Db.close (); Close the database
})
})

}

/* Insert Data */
Exports.insertone=function (Collectionname,json,callback) {


_connectdb (function (err,db) {
Db.collection (CollectionName). Insertone (JSON, function (err, result) {
Callback (err, result);
Db.close (); Close the database
})
})

}
/* Update Data */


Modify a Bar
Exports.updateone = function (CollectionName, Json1, Json2, callback) {
_connectdb (function (err, db) {
Db.collection (CollectionName). Updateone (
Json1,
Json2,
function (err, results) {
Callback (err, results);
Db.close ();//Close Database
});
})
}
Modify All
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 ();//Close Database
});
})


}


Find

Requires a minimum of 4 parameters
Db.find (' table name ', {},{},function () {
//
//})

CollectionName Table Name

Json1 Query criteria
Columns returned by Json2
C Configuration Callback
D Callback

Exports.find=function (CollectionName, Json1,json2, C, D) {

if (arguments.length<4) {

Console.log (' Incoming parameter is incorrect ');
return false;
}

var result = []; Result array
if (arguments.length = = 4) {
Then the parameter C is callback, and parameter d is not passed.
var callback = C;
var skipnumber = 0;
Number limit
var limit = 0;
} else if (arguments.length = = 5) {
var callback = D;
var args = C; /* Configuration */
Number of bars that should be omitted 1
var skipnumber = args.pagesize * (args.page-1) | | 0;

Page=1 first page: Skip (0)
page=2 first page: Skip (2)
Page=3 first page: Skip (4)
Page=4 first page: Skip (6)

Number limit
var limit = Args.pagesize | | 20;
Sorting method
var sort = Args.sort | | {};
} else {
throw new Error ("The number of arguments to the Find function must be 3, or 4.") ");
Return
}


_connectdb (function (err,db) {


if (err) {/* database connection Failed */

Console.log (' Database connection failed ');
Return
}


var userrel=db.collection (CollectionName). Find (JSON);
var userrel=db.collection (CollectionName). Find (Json1,json2). Skip (Skipnumber). Limit. Sort (sort);


Userrel.each (function (err, doc) {

if (err) {
Res.write ("Cursor traversal error");
Return
}
if (doc! = null) {
Result.push (DOC);
} else {
Console.log (result);
Traverse complete
Db.close ();
Callback (Err,result)
}
});

})




}



//
Find
Exports.find=function (CollectionName, JSON, C, D) {
//
//
//
var result = []; Result array
if (arguments.length = = 3) {
Then the parameter C is callback, and parameter d is not passed.
var callback = C;
var skipnumber = 0;
Number limit
var limit = 0;
} else if (arguments.length = = 4) {
var callback = D;
var args = C; /* Configuration */
Number of bars that should be omitted 1
var skipnumber = args.pagesize * (args.page-1) | | 0;
//
//page=1 first page: Skip (0)
page=2 first page: Skip (2)
Page=3 first page: Skip (4)
Page=4 first page: Skip (6)
//
Number limit
var limit = Args.pagesize | | 20;
Sorting method
var sort = Args.sort | | {};
} else {
throw new Error ("The number of arguments to the Find function must be 3, or 4.") ");
Return
//    }
//
//
_connectdb (function (err,db) {
//
//
if (err) {/* database connection Failed */
//
Console.log (' Database connection failed ');
Return
//            }
//
//
var userrel=db.collection (CollectionName). Find (JSON);
var userrel=db.collection (CollectionName). Find (JSON). Skip (Skipnumber). Limit. Sort (sort);
//
//
Userrel.each (function (err, doc) {
//
if (err) {
Res.write ("Cursor traversal error");
Return
//                }
if (doc! = null) {
Result.push (DOC);
} else {
Console.log (result);
Traverse complete
Db.close ();
Callback (Err,result)
//                }
//            });
//
//    })
//
//
//
//
//}

Delete
Exports.deletemany = function (CollectionName, JSON, callback) {
_connectdb (function (err, db) {
Delete
Db.collection (CollectionName). Deletemany (
Json
function (err, results) {
Callback (err, results);
Db.close (); Close the database
}
);
});
}

node. JS Query Statement Encapsulation