Why do we need connection strings?

Question

When we connect to a database in ASP.NET you must specify the appropriate connection string. However most other instances where data is to be specified is done within an object.

For example why couldn't we have connection objects such as:

var connection = new connectionObject(){
   DataSource = "myServerAddress",
   IntialCatalog = "myDataBase",
   UserId = "myUsername",
   Password = "myPassword"
}

which is far better than some key/value string:

Data Source=myServerAddress;Initial Catalog=myDataBase;UserId=myUsername;Password=myPassword;

The only reason I can think of is to allow storage in web.config, but there would be nothing stopping us storing the individual values in there anyway.

I'm sure there are good reasons, but what are they?

When the connectionstring was born, OOP was not really available, I think :-) — Rhapsody
You could have a bit of fun and make your own connection object class, whose ToString() would build the appropriate connection string using its properties. — BoltClock
Legacy. But I suppose there's nothing stopping you from creating a connection string formatter class with properties. — Vlad
@BoltClock, +Vlad: DbConnectionBuilder seems to do pretty much what you are describing. It's name/value pairs instead of predefined properties, though. — Randy supports Monica
For provider connection strings you can use provider specific versions of DbConnectionBuilder. E.g. SqlConnectionBuilder exposes strongly typed properties of known SQL Server key/value pairs. — Randy supports Monica

Henk Holterman Henk Holterman · Accepted Answer · 2011-11-22T14:25:35

Legacy, tradition but above all : flexibility.

Try to write (or just imagine) the connectionConfig object that could handle all the MS-SQL, Oracle and (nested) ODBC configurations. And that's only a few of the databases supporting .NET.

Also, the main purpose of such an object would be to be serialized in a (somewhat) human-readable form.

So XML is an alternative, a fixed (set of) objects is not.

Why do we need connection strings?

6 Answers