Requirements:
1) MongoDB installable
2) MongoDB C# driver
3) VS.Net 2008 / 2010.
Before we begin:
1) Install MongoDB as per the instruction given on the MongoDB website.
a. For development version, just download the .zip file, extract to specific folder
b. Crete a folder with name “Data” and a subfolder with name “DB” like in “d:\ Data\DB”
c. Open a command prompt, navigate to the MongoDB folder with extracted MongoDB binaries and start MongoDB using the command “D:\MongoDB\bin\mongod.exe --dbpath "D:\MongoDB\Data\DB"” if in case DBPath happens to be “C:\ Data\DB” then the command “D:\MongoDB\bin\mongod.exe” is enough to start the database.
2) Installation of MongoDB driver
a. Download the C# drivers from website.
b. Extract the binaries (optionally including source).
Start visual studio 2010, add a new windows application project, with few text boxes, a grid and a command button to specify the values and operate upon the items. Name the controls appropriately.
Figure 1 : VS2010 win form application
Add a new class, let’s call this Entity, the definition of the class is as follows.
namespace MongoDB
{
class Entity
{
public string Prop1 { get; set; }
public string Prop2 { get; set; }
public string Prop3 { get; set; }
public string Prop4 { get; set; }
public string Prop5 { get; set; }
public Bson.BsonObjectId _id { get; set; }
}
}
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Following code helps in setting the stage for getting connected to MongoDB
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using MongoDB.Driver;
using MongoDB.Driver.Builders;
namespace MongoDB
{
public partial class frmMain : Form
{
private const string mongoConnStr = "mongodb://localhost/?safe=true";
private MongoCollection<Entity> collection;
private Entity _entity; // selected entity
private void frmMain_Load(object sender, EventArgs e)
{
var server = MongoServer.Create(mongoConnStr);
var database = server.GetDatabase("test");
if (!database.CollectionExists("entities"))
{
database.CreateCollection("entities");
}
collection = database.GetCollection<Entity>("entities");
PopulcateGrid();
}
void PopulcateGrid()
{
List<Entity> list = collection.FindAllAs<Entity>().ToList();
dg.DataSource = list;
Clear();
}
void Clear()
{
_entity = null;
txt1.Text = string.Empty;
txt2.Text = string.Empty;
txt3.Text = string.Empty;
txt4.Text = string.Empty;
txt5.Text = string.Empty;
}
}
}
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Here what we have done is declared a mongo connection string as “mongodb://localhost/?safe=true”, created a mongo Server using the mentioned connection string and finally pointed to the “test” database on the server and “entities” collection within the database. All these happens within the form_Load event of the main form.
The form_Load first checks for the existence of the “entities” collection within the database, if not then it creates a new collection by the name “entities”. The PopulcateGrid() function and Clear() functions are straight forward, used to populated the grid and initialize the controls.
The grid_Click event uses the search function to identify the selected entity and populate the respective values into the text boxes.
private void dg_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
// ground work for updation
if (e.RowIndex < 0) return;
List<Entity> list = dg.DataSource as List<Entity>;
_entity = list[e.RowIndex];
txt1.Text = _entity.Prop1;
txt2.Text = _entity.Prop2;
txt3.Text = _entity.Prop3;
txt4.Text = _entity.Prop4;
txt5.Text = _entity.Prop5;
}
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Double click event on the grid deletes the selected entity from the collection and database and refreshes the grid. Selection of entity item is based on _id of the entity through IMongoQuery object, created using static method Query.EQ.
private void dg_CellContentDblClick(object sender, DataGridViewCellEventArgs e)
{
//delete
if (e.RowIndex < 0) return;
List<Entity> list = dg.DataSource as List<Entity>;
Entity item = list[e.RowIndex];
IMongoQuery query = Query.EQ("_id", item._id);
collection.Remove(query);
PopulcateGrid();
}
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Insert and update is handled by the Insert / update command button, depending upon the state of the _entity private object (set by single clicking a row on the grid).
// insert / update
if (_entity == null)
{
_entity = new Entity()
{
Prop1 = txt1.Text,
Prop2 = txt2.Text,
Prop3 = txt3.Text,
Prop4 = txt4.Text,
Prop5 = txt5.Text
};
collection.Insert(_entity);
}
else // update
{
_entity.Prop1 = txt1.Text;
_entity.Prop2 = txt2.Text;
_entity.Prop3 = txt3.Text;
_entity.Prop4 = txt4.Text;
_entity.Prop5 = txt5.Text;
IMongoQuery query = Query.EQ("_id", _entity._id);
IMongoUpdate update = MongoDB.Driver.Builders.Update
.Set("Prop1", _entity.Prop1)
.Set("Prop2", _entity.Prop2)
.Set("Prop3", _entity.Prop3)
.Set("Prop4", _entity.Prop4)
.Set("Prop5", _entity.Prop5);
collection.Update(query,update);
}
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The entire code for the windows form is printed below
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using MongoDB.Driver;
using MongoDB.Driver.Builders;
namespace MongoDB
{
public partial class frmMain : Form
{
private const string mongoConnStr = "mongodb://localhost/?safe=true";
private MongoCollection<Entity> collection;
private Entity _entity; // selected entity
public frmMain()
{
InitializeComponent();
}
private void btnInsert_Click(object sender, EventArgs e)
{
// insert / update
if (_entity == null)
{
_entity = new Entity()
{
Prop1 = txt1.Text,
Prop2 = txt2.Text,
Prop3 = txt3.Text,
Prop4 = txt4.Text,
Prop5 = txt5.Text
};
collection.Insert(_entity);
}
else
{
_entity.Prop1 = txt1.Text;
_entity.Prop2 = txt2.Text;
_entity.Prop3 = txt3.Text;
_entity.Prop4 = txt4.Text;
_entity.Prop5 = txt5.Text;
IMongoQuery query = Query.EQ("_id", _entity._id);
IMongoUpdate update = MongoDB.Driver.Builders.Update
.Set("Prop1", _entity.Prop1)
.Set("Prop2", _entity.Prop2)
.Set("Prop3", _entity.Prop3)
.Set("Prop4", _entity.Prop4)
.Set("Prop5", _entity.Prop5);
collection.Update(query,update);
}
PopulcateGrid();
}
private void frmMain_Load(object sender, EventArgs e)
{
var server = MongoServer.Create(mongoConnStr);
var database = server.GetDatabase("test");
if (!database.CollectionExists("entities"))
{
database.CreateCollection("entities");
}
collection = database.GetCollection<Entity>("entities");
PopulcateGrid();
}
private void dg_CellContentDblClick(object sender, DataGridViewCellEventArgs e)
{
//delete
if (e.RowIndex < 0) return;
List<Entity> list = dg.DataSource as List<Entity>;
Entity item = list[e.RowIndex];
IMongoQuery query = Query.EQ("_id", item._id);
collection.Remove(query);
PopulcateGrid();
}
void Clear()
{
_entity = null;
txt1.Text = string.Empty;
txt2.Text = string.Empty;
txt3.Text = string.Empty;
txt4.Text = string.Empty;
txt5.Text = string.Empty;
}
void PopulcateGrid()
{
List<Entity> list = collection.FindAllAs<Entity>().ToList();
dg.DataSource = list;
Clear();
}
private void dg_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
// ground work for updation
if (e.RowIndex < 0) return;
List<Entity> list = dg.DataSource as List<Entity>;
_entity = list[e.RowIndex];
txt1.Text = _entity.Prop1;
txt2.Text = _entity.Prop2;
txt3.Text = _entity.Prop3;
txt4.Text = _entity.Prop4;
txt5.Text = _entity.Prop5;
}
}
}
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Enjoy!!!
