Last month I compared several Linq providers. Lately I’ve been playing with MongoDB. MongoDB is a Document (read NoSQL) database that runs on windows and has a .NET provider.
To do this, I am going to set up an environment with the same data as I used in the previous examples (the infamous Northwind database from SQL Server).
Create the Data
To recreate the data from Northwind, I wrote the following query to create insert statements.
SELECT 'db.Product.insert({'
+ 'ProductID: ' + CAST(p.ProductID AS VARCHAR(10)) + ', '
+ 'ProductName: "' + p.ProductName + '", '
+ 'SupplierID: ' + CAST(p.SupplierID AS VARCHAR(10)) + ', '
+ 'CategoryID: ' + CAST(p.CategoryID AS VARCHAR(10)) + ', '
+ 'QuantityPerUnit: "' + p.QuantityPerUnit + '", '
+ 'UnitPrice: ' + CAST(p.UnitPrice AS VARCHAR(10)) + ', '
+ 'UnitsInStock: ' + CAST(p.UnitsInStock AS VARCHAR(10)) + ', '
+ 'UnitsOnOrder: ' + CAST(p.UnitsOnOrder AS VARCHAR(10)) + ', '
+ 'ReorderLevel: ' + CAST(p.ReorderLevel AS VARCHAR(10)) + ', '
+ 'Discontinued: ' + CASE WHEN p.Discontinued = 1 THEN '"true"' ELSE '"false"' END + ', '
+ 'CategoryName: "' + c.CategoryName + '"'
+ '})'
FROM Northwind.dbo.Products p
JOIN Northwind.dbo.Categories c ON p.CategoryID = c.CategoryID
ORDER BY p.ProductID
I run the above query against a Northwind Database that I have lying around on my home computer and I pasted the result set into a Mongo Shell window.
Notice that I added CategoryName to Product. From a relational point of view, this is criminal. However, Mongo is a DOCUMENT database and repeating data isn’t quite sin; I am also leaving this in the CategoryName because repeating data is in the spirit of document databases as I understand them. (Besides the version of MongoDB.DLL I’m using doesn’t appear to support joins very well.)
The POCO Class
To run straightforward Linq queries using MongoDB.DLL, I need a POCO class to hydrate the data into. Since MongoDB is a document database, the data can be unstructured, but to work in Linq, structured data makes things easier.
public class Product
{
public int ProductID { get; set; }
public string ProductName { get; set; }
public int SupplierID { get; set; }
public int CategoryID { get; set; }
public string QuantityPerUnit { get; set; }
public decimal UnitPrice { get; set; }
public int UnitsInStock { get; set; }
public int UnitsOnOrder { get; set; }
public int ReorderLevel { get; set; }
public bool Discontinued { get; set; }
public string CategoryName { get; set; }
}
The Code
Now that I have copied the data that I need to “simulate” the Northwind Product and Category data into a MongoDB collection, I can use this code to do the same thing as I did in the last post:
public static IMongoDatabase GetContext()
{
var mongo = new Mongo();
mongo.Connect();
return mongo.GetDatabase("Northwind");
}
public static void DoDemo()
{
var mdb = GetContext();
var list = from p in mdb.GetCollection().Linq()
where p.CategoryName == "Seafood"
orderby p.ProductName
select new
{
p.ProductID,
p.ProductName,
p.UnitPrice,
p.CategoryName
};
Console.WriteLine("MongoDB Demo");
foreach (var item in list)
{
Console.WriteLine(
string.Format("{0}\t{1:c}\t{2}\t{3}",
item.ProductID,
item.UnitPrice,
item.ProductName,
item.CategoryName));
}
}
GetContext() is straight forward: You new-up a Mongo, connect and get a database.
The most interesting statement is mdb.GetCollection().Linq(). The GetCollection method links the content with the name of T to an IMongoCollection of Ts. LinqExtensions.Linq() is an extension method that converts the IMongoCollection to IQueryable.
Last month I compared several Linq providers. Lately I’ve been playing with MongoDB. MongoDB is a Document (read NoSQL) database that runs on windows and has a .NET provider.
To do this, I am going to set up an environment with the same data as I used in the previous examples (the infamous Northwind database from SQL Server).
Create the Data
To recreate the data from Northwind, I wrote the following query to create insert statements.
SELECT 'db.Product.insert({'
+ 'ProductID: ' + CAST(p.ProductID AS VARCHAR(10)) + ', '
+ 'ProductName: "' + p.ProductName + '", '
+ 'SupplierID: ' + CAST(p.SupplierID AS VARCHAR(10)) + ', '
+ 'CategoryID: ' + CAST(p.CategoryID AS VARCHAR(10)) + ', '
+ 'QuantityPerUnit: "' + p.QuantityPerUnit + '", '
+ 'UnitPrice: ' + CAST(p.UnitPrice AS VARCHAR(10)) + ', '
+ 'UnitsInStock: ' + CAST(p.UnitsInStock AS VARCHAR(10)) + ', '
+ 'UnitsOnOrder: ' + CAST(p.UnitsOnOrder AS VARCHAR(10)) + ', '
+ 'ReorderLevel: ' + CAST(p.ReorderLevel AS VARCHAR(10)) + ', '
+ 'Discontinued: ' + CASE WHEN p.Discontinued = 1 THEN '"true"' ELSE '"false"' END + ', '
+ 'CategoryName: "' + c.CategoryName + '"'
+ '})'
FROM Northwind.dbo.Products p
JOIN Northwind.dbo.Categories c ON p.CategoryID = c.CategoryID
ORDER BY p.ProductID
I run the above query against a Northwind Database that I have lying around on my home computer and I pasted the result set into a Mongo Shell window.
Notice that I added CategoryName to Product. From a relational point of view, this is criminal. However, Mongo is a DOCUMENT database and repeating data isn’t quite sin; I am also leaving this in the CategoryName because repeating data is in the spirit of document databases as I understand them. (Besides the version of MongoDB.DLL I’m using doesn’t appear to support joins very well.)
The POCO Class
To run straightforward Linq queries using MongoDB.DLL, I need a POCO class to hydrate the data into. Since MongoDB is a document database, the data can be unstructured, but to work in Linq, structured data makes things easier.
public class Product
{
public int ProductID { get; set; }
public string ProductName { get; set; }
public int SupplierID { get; set; }
public int CategoryID { get; set; }
public string QuantityPerUnit { get; set; }
public decimal UnitPrice { get; set; }
public int UnitsInStock { get; set; }
public int UnitsOnOrder { get; set; }
public int ReorderLevel { get; set; }
public bool Discontinued { get; set; }
public string CategoryName { get; set; }
}
The Code
Now that I have copied the data that I need to “simulate” the Northwind Product and Category data into a MongoDB collection, I can use this code to do the same thing as I did in the last post:
public static IMongoDatabase GetContext()
{
var mongo = new Mongo();
mongo.Connect();
return mongo.GetDatabase("Northwind");
}
public static void DoDemo()
{
var mdb = GetContext();
var list = from p in mdb.GetCollection().Linq()
where p.CategoryName == "Seafood"
orderby p.ProductName
select new
{
p.ProductID,
p.ProductName,
p.UnitPrice,
p.CategoryName
};
Console.WriteLine("MongoDB Demo");
foreach (var item in list)
{
Console.WriteLine(
string.Format("{0}\t{1:c}\t{2}\t{3}",
item.ProductID,
item.UnitPrice,
item.ProductName,
item.CategoryName));
}
}
GetContext() is straight forward: You new-up a Mongo, connect and get a database.
The most interesting statement is mdb.GetCollection().Linq(). The GetCollection method links the content with the name of T to an IMongoCollection of Ts. LinqExtensions.Linq() is an extension method that converts the IMongoCollection to IQueryable.
