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By Ziran Sun
The first part of this article
illustrated how to install and configure the MySQL Database Server, install and use the
MySQL Administrator, create a new database, and create and populate a new sample table with
some sample data.
Now that the database server is up and running, this part of the article will complete our coverage
of using MySQL with ASP.NET by covering how to:
- Add a new MySQL user.
- Assign the new user the appropriate permisions to the database.
- Connect to the MySQL server from .NET.
- Build a simple ASP.NET page to query the database.
Step 7 – Creating a New MySQL User Account
I’m assuming that you’re been following along with part one, so at this point you should have
the MySQL Server and MySQL Adminstrator installed, and have a sample database named “mydatabase”
which contains a sample table named “mytable” with two rows of data in it.
In order to add a new user account, we’ll once again need to run MySQL Administrator and
login to your server using the password you set during installation.
You’ll then want to select the "User Administration" item from the list of items at the
left of the MySQL Administrator window.
This should bring up a list of the current user account on the server
(There should already be once called "root").
If you right-click in the small window where the users are listed you should get the option to
"Add new User".
You’ll then be prompted to enter the new user’s details.
I’ve named the user "15secs" and assigned a password of "password".
Once you’ve finished entering the user’s details press "Apply Changes" to save your modifications.
Step 8 – Granting the User Account Access to the Database
By default new users have permission to do almost nothing. In order to allow our new user to connect to the MySQL
database server, we need to grant him what MySQL calls "Schema Privileges". This is naturally done from the
"Schema Privileges" tab in MySQL Administrator.
Notice in the above screen capture that the user has no "Assigned Privileges" to the "mydatabase"
database. Since the user will need to be able to query the database to run the sample code which follows, I’m now
going to assign the user the "SELECT" privilege by highlighting it in the
"Available Privileges" column and clicking the arrow to move it to the
"Assigned Privileges" column. Once again I’ll click the "Apply Changes" button to save changes.
Depending on your application the user may very well need more permission then I’ve assigned to "15secs".
Most non-trivial applications will probably need at least "INSERT", "UPDATE", and "DELETE"
permissions in addition to "SELECT",
but it’s always best to err on the side of caution and add more permissions as they are needed then to simply
give everyone full control.
Step 9 – Connecting to the Database Server from an ASP.NET Page
To my knowledge there are currently two main ways to connect to a MySQL database server from .NET: MySQL Connector/ODBC (aka. MyODBC) and MySQL Connector/Net. While the ODBC connector is
cross-platform and is compliant with ODBC standards, the .NET version is generally the better
choice when using MySQL with .NET.
The setup files can be downloaded from the MySQL Connector/Net page and installation is straight-forward.
Note: Even though I selected the option to register Connector/NET in the Global Assembly Cache
and when I checked it later I found that it actually was installed there, until I copied the MySql.Data.dll file to my application’s /bin
folder I couldn’t get the import statement to find the Connector/NET’s namespace. The exact error message was:
BC30466: Namespace or type specified in the Imports 'MySql.Data.MySqlClient' cannot be found.I’m not sure what the problem was/is, but I
looked around and it seems some others are having the same issue. So, for the time being, placing another copy of the
file from it’s installed location (ie. C:\Program Files\MySQL\MySQL Connector Net 1.0.4\bin\.NET 1.1\) to your
application’s /bin folder (ie. C:\Inetpub\wwwroot\bin\) should resolve the issue.
Step 10 – A Sample ASP.NET Page to Query a MySQL Database
So with our MySQL database finally squared away and MySQL Connector/Net installed, we can now
start using MySQL from our ASP.NET web pages. For illustration I’m going to provide a very simple
script with no bells and whistles. You can find fancy database scripts all over the web. The point
of this one is simply to show you what you need to do to connect to MySQL. Don’t get me wrong… all that
fancy stuff works just fine using MySQL (and usually with very few changes) but that’s just not
the point of this script.
MySQL.aspx
<%@ Page Language="VB" debug="true" %>
<%@ Import Namespace = "System.Data" %>
<%@ Import Namespace = "MySql.Data.MySqlClient" %>
<script language="VB" runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
Dim myConnection As MySqlConnection
Dim myDataAdapter As MySqlDataAdapter
Dim myDataSet As DataSet
Dim strSQL As String
Dim iRecordCount As Integer
myConnection = New MySqlConnection("server=localhost; user id=15secs; password=password; database=mydatabase; pooling=false;")
strSQL = "SELECT * FROM mytable;"
myDataAdapter = New MySqlDataAdapter(strSQL, myConnection)
myDataSet = New Dataset()
myDataAdapter.Fill(myDataSet, "mytable")
MySQLDataGrid.DataSource = myDataSet
MySQLDataGrid.DataBind()
End Sub
</script>
<html>
<head>
<title>Simple MySQL Database Query</title>
</head>
<body>
<form runat="server">
<asp:DataGrid id="MySQLDataGrid" runat="server" />
</form>
</body>
</html>
In the above script, I’ve highlighted the places where the script varies from one you would use to
perform the same thing using Microsoft SQL Server or Access. As you can see there’s really nothing
new here. Instead of importing System.Data.SQLClient like we would for MS SQL,
we import MySql.Data.MySqlClient. Oh and if at any point you need a reference for the MySql.Data.MySqlClient namespace,
you’re in luck… it ships with one.
Here’s a screen capture of what the script above produces when run against the sample database and
table we set up in this article. Like I said, it may not be pretty, but there’s no reason it couldn’t be.
I’m just keeping it simple for illustration.
Conclusion
In part one of this article I illustrated how to:
- Download and install the MySQL Database Server.
- Configure the server.
- Install MySQL Administrator to make managing the database easier.
- Create a new database named "mydatabase".
- Create a new table named "mytable" in that database.
- Add a couple rows of sample data to that table.
This part illustrated how to do the following:
- Add a new MySQL user.
- Assign the new user the appropriate permisions to the database.
- Connect to the MySQL server from .NET.
- Build a simple ASP.NET page to query the database.
I hope this article helped ease your introduction to this great little database server.
Whether you are upgrading from Access or starting from scratch, MySQL is certainly a viable
option and despite the fact that it’s open-source and not shipped from Redmond,
it really does work great with .NET. And, with the addition of MySQL Administrator,
management is no longer the source of nightmares that it used to be. Hopefully the next
time you’re looking for a database server to use as the backend for your .NET application,
you’ll at least consider using MySQL.
