MySQL Visual Basic
last modified July 6, 2020
This is a Visual Basic tutorial for the MySQL database. It covers the basics of MySQL programming with Visual Basic. In this tutorial, we use the Connector/Net driver. This driver is based on the ADO.NET specification. The examples were created and tested on Ubuntu Linux. There is a similar MySQL C# tutorial, MySQL Perl tutorial and SQLite Visual Basic tutorial on ZetCode.
If you need to refresh your knowledge of the Visual Basic language, there is a full Visual Basic tutorial on ZetCode.
About MySQL database
MySQL is a leading open source database management system. It is a multi user, multithreaded database management system. MySQL is especially popular on the web. It is one of the parts of the very popular LAMP platform consisting of Linux, Apache, MySQL, and PHP. Currently MySQL is owned by Oracle. MySQL database is available on most important OS platforms. It runs on BSD Unix, Linux, Windows, or Mac OS. Wikipedia and YouTube use MySQL. These sites manage millions of queries each day. MySQL comes in two versions: MySQL server system and MySQL embedded system.
Before we start
We need to install several packages to execute the examples in this tutorial:
libmysql6.1-cil, mysql-server, mysql-client.
We need to install Visual Basic compiler from the Mono project. Either from a package
or from sources.
The libmysql6.1-cil is the MySQL database connector for CLI. It is written in C# and is available for all CLI languages. C#, Visual Basic, Boo and others.
$ ls /usr/lib/cli/MySql.Data-6.1/MySql.Data.dll /usr/lib/cli/MySql.Data-6.1/MySql.Data.dll
From the technical point of view, we need a DLL. On my system (Ubuntu Lucid Lynx), it was located under the above path. We need to know the path to the DLL library. To compile our examples.
If you don't already have MySQL installed, we must install it.
$ sudo apt-get install mysql-server
This command installs the MySQL server and various other packages. While installing the package, we are prompted to enter a password for the MySQL root account.
Next, we are going to create a new database user and a new database.
We use the mysql client.
$ service mysql status mysql start/running, process 1238
We check if the MySQL server is running. If not, we need
to start the server. On Ubuntu Linux, this can be done
with the service mysql start command.
$ mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 30 Server version: 5.0.67-0ubuntu6 (Ubuntu) Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | +--------------------+ 2 rows in set (0.00 sec)
We use the mysql monitor client application to connect to the
server. We connect to the database using the root account. We show all available
databases with the SHOW DATABASES statement.
mysql> CREATE DATABASE testdb; Query OK, 1 row affected (0.02 sec)
We create a new testdb database. We will use this database throughout
the tutorial.
mysql> CREATE USER 'testuser'@'localhost' IDENTIFIED BY 'test623'; Query OK, 0 rows affected (0.00 sec) mysql> USE testdb; Database changed mysql> GRANT ALL ON testdb.* TO 'testuser'@'localhost'; Query OK, 0 rows affected (0.00 sec) mysql> quit; Bye
We create a new database user. We grant all privileges to this user
for all tables of the testdb database.
Definitions
ADO.NET is an important part of the .NET framework. It is a specification
that unifies access to relational databases, XML files and other application data.
A MySQL Connector/Net is an implementation of the ADO.NET specification
for the MySQL database. It is a driver written in C# language and is available for
all .NET languages.
The Connection, Command, DataReader,
DataSet, and DataProvider are the core elements
of the .NET data provider model. The Connection creates a connection to
a specific data source. The Command object executes an SQL statement
against a data source. The DataReader reads streams of data from a
data source. The DataSet object is used for offline work with a mass
of data. It is a disconnected data representation that can hold data from
a variety of different sources. Both DataReader and DataSet
are used to work with data; they are used under different circumstances. If we only
need to read the results of a query, the DataReader is the better choice.
If we need more extensive processing of data, or we want to bind a Winforms
control to a database table, the DataSet is preferred.
MySQL version
If the following program runs OK, then we have everything installed OK. We check the version of the MySQL server.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Try
conn.Open()
Console.WriteLine("MySQL version : {0}", conn.ServerVersion)
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
End Module
We connect to the database and get some info about the MySQL server.
Imports MySql.Data.MySqlClient
We import the elements of the MySQL data provider.
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
This is the connection string. It is used by the data provider to establish a connection to the database. We specify the database name, host, user name and password.
Dim conn As New MySqlConnection(cs)
A MySQLConnection object is created. This object is used to
open a connection to a database.
conn.Open()
This line opens the connection.
Console.WriteLine("MySQL version : {0}", conn.ServerVersion)
Here we print the version of MySQL using the ServerVersion
property of the connection object.
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
In case of an exception, we print the error message to the console.
$ vbnc -r:/usr/lib/cli/MySql.Data-6.1/MySql.Data.dll connect.vb
We compile our example. A path to the MySQL connector DLL is provided.
$ ./connect.exe MySQL version : 5.1.41-3ubuntu12.6
This is the output of the program on my system.
A more complex program follows.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim stm As String = "SELECT VERSION()"
Dim version As String
Dim conn As MySqlConnection
Try
conn = New MySqlConnection(cs)
conn.Open()
Dim cmd As MySqlCommand = New MySqlCommand(stm, conn)
version = Convert.ToString(cmd.ExecuteScalar())
Console.WriteLine("MySQL version: {0}", version)
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
End Module
We check for the version of the MySQL database. This time using an SQL query.
Dim stm As String = "SELECT VERSION()"
This is the SQL SELECT statement. It returns the version
of the database. The VERSION is a built-in MySQL function.
Dim cmd As MySqlCommand = New MySqlCommand(stm, conn)
The MySqlCommand is an object, which is
used to execute a query on the database. The parameters are the
SQL statement and the connection object.
version = Convert.ToString(cmd.ExecuteScalar())
There are queries which return only a scalar value. In our
case, we want a simple string specifying the version of the
database. The ExecuteScalar is
used in such situations. We avoid the overhead of using more
complex objects.
$ ./connect2.exe MySQL version : 5.1.41-3ubuntu12.6
Same result as in the previous example.
Creating and populating tables
Next we are going to create database tables and fill them with data. These tables will be used throughout this tutorial.
DROP TABLE IF EXISTS Books, Authors;
CREATE TABLE IF NOT EXISTS Authors(Id INT PRIMARY KEY AUTO_INCREMENT,
Name VARCHAR(25)) ENGINE=INNODB;
INSERT INTO Authors(Id, Name) VALUES(1, 'Jack London');
INSERT INTO Authors(Id, Name) VALUES(2, 'Honore de Balzac');
INSERT INTO Authors(Id, Name) VALUES(3, 'Lion Feuchtwanger');
INSERT INTO Authors(Id, Name) VALUES(4, 'Emile Zola');
INSERT INTO Authors(Id, Name) VALUES(5, 'Truman Capote');
CREATE TABLE IF NOT EXISTS Books(Id INT PRIMARY KEY AUTO_INCREMENT,
AuthorId INT, Title VARCHAR(100),
FOREIGN KEY(AuthorId) REFERENCES Authors(Id) ON DELETE CASCADE)
ENGINE=INNODB;
INSERT INTO Books(Id, AuthorId, Title) VALUES(1, 1, 'Call of the Wild');
INSERT INTO Books(Id, AuthorId, Title) VALUES(2, 1, 'Martin Eden');
INSERT INTO Books(Id, AuthorId, Title) VALUES(3, 2, 'Old Goriot');
INSERT INTO Books(Id, AuthorId, Title) VALUES(4, 2, 'Cousin Bette');
INSERT INTO Books(Id, AuthorId, Title) VALUES(5, 3, 'Jew Suess');
INSERT INTO Books(Id, AuthorId, Title) VALUES(6, 4, 'Nana');
INSERT INTO Books(Id, AuthorId, Title) VALUES(7, 4, 'The Belly of Paris');
INSERT INTO Books(Id, AuthorId, Title) VALUES(8, 5, 'In Cold blood');
INSERT INTO Books(Id, AuthorId, Title) VALUES(9, 5, 'Breakfast at Tiffany');
We have a books.sql file. It creates two database tables: Authors,
and Books. The tables are of InnoDB type. InnoDB databases support
foreign key constraints and transactions. We place a foreign key constraint on the
AuthorId column of the Books table. We fill the tables
with initial data.
mysql> source books.sql Query OK, 0 rows affected (0.07 sec) Query OK, 0 rows affected (0.12 sec) Query OK, 1 row affected (0.04 sec) ...
We use the source command to execute the books.sql script.
In the following example, we are going to insert a new author
into the Authors table.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim connString As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(connString)
Dim cmd As New MySqlCommand()
Try
conn.Open()
cmd.Connection = conn
cmd.CommandText = "INSERT INTO Authors(Name) VALUES(@Name)"
cmd.Prepare()
cmd.Parameters.AddWithValue("@Name", "Trygve Gulbranssen")
cmd.ExecuteNonQuery()
conn.Close()
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
End Try
End Sub
End Module
We add a new author to the Authors table. We use a parameterized command.
cmd.CommandText = "INSERT INTO Authors(Name) VALUES(@Name)" cmd.Prepare()
Here we create a prepared statement. When we write prepared statements, we use
placeholders instead of directly writing the values into the statements.
Prepared statements are faster and guard against SQL injection attacks.
The @Name is a placeholder, which is going to be filled later.
cmd.Parameters.AddWithValue("@Name", "Trygve Gulbranssen")
A value is bound to the placeholder.
cmd.ExecuteNonQuery()
The prepared statement is executed. We use the ExecuteNonQuery
method of the MySQLCommand object when we don't expect any data to
be returned. This is when we create databases or execute INSERT,
UPDATE, DELETE statements.
$ ./prepared.exe mysql> select * from Authors; +----+--------------------+ | Id | Name | +----+--------------------+ | 1 | Jack London | | 2 | Honore de Balzac | | 3 | Lion Feuchtwanger | | 4 | Emile Zola | | 5 | Truman Capote | | 6 | Trygve Gulbranssen | +----+--------------------+ 6 rows in set (0.00 sec)
We have a new author inserted into the table.
Retrieving data with MySqlDataReader
The MySqlDataReader is an object used
to retrieve data from the database. It provides fast, forward-only,
read-only access to query results. It is the most efficient way
to retrieve data from tables.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Try
conn.Open()
Dim stm As String = "SELECT * FROM Authors"
Dim cmd As MySqlCommand = New MySqlCommand(stm, conn)
Dim reader As MySqlDataReader = cmd.ExecuteReader()
While reader.Read()
Console.WriteLine(reader.GetInt32(0) & ": " _
& reader.GetString(1))
End While
reader.Close()
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
End Module
We get all authors from the Authors table and print
them to the console.
Dim reader As MySqlDataReader = cmd.ExecuteReader()
To create a MySQLDataReader, we must call
the ExecuteReader method of the
MySqlCommand object.
While reader.Read()
Console.WriteLine(reader.GetInt32(0) & ": " _
& reader.GetString(1))
End While
The Read method advances the data reader to the next record.
It returns true if there are more rows; otherwise false. We can retrieve
the value using the array index notation, or use a specific method to access
column values in their native data types. The latter is more efficient.
reader.Close()
Always call the Close method when done reading.
$ ./read.exe 1: Jack London 2: Honore de Balzac 3: Lion Feuchtwanger 4: Emile Zola 5: Truman Capote 6: Trygve Gulbranssen
This is the output of the example.
Column headers
Next we will show, how to print column headers with the data from the database table.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim connString As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(connString)
Try
conn.Open()
Dim stm As String = "SELECT Name, Title From Authors, " _
& "Books WHERE Authors.Id=Books.AuthorId"
Dim cmd As MySqlCommand = New MySqlCommand(stm, conn)
Dim reader As MySqlDataReader = cmd.ExecuteReader()
Console.WriteLine("{0} {1}", reader.GetName(0), _
reader.GetName(1).PadLeft(18))
While reader.Read()
Console.WriteLine(reader.GetString(0).PadRight(18) _
& reader.GetString(1))
End While
reader.Close()
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
End Module
In this program, we select authors from the Authors table
and their books from the Books table.
Dim stm As String = "SELECT Name, Title From Authors, " _
& "Books WHERE Authors.Id=Books.AuthorId"
This is the SQL statement which joins authors with their books.
Dim reader As MySqlDataReader = cmd.ExecuteReader()
We create a MySqlDataReader object.
Console.WriteLine("{0} {1}", reader.GetName(0), _
reader.GetName(1).PadLeft(18))
We get the names of the columns with the GetName
method of the reader. The PadLeft method returns
a new string of a specified length in which the beginning of the current string
is padded with spaces. We use this method to align strings properly.
While reader.Read()
Console.WriteLine(reader.GetString(0).PadRight(18) _
& reader.GetString(1))
End While
We print the data that was returned by the SQL statement to the terminal.
$ ./columns.exe Name Title Jack London Call of the Wild Jack London Martin Eden Honore de Balzac Old Goriot Honore de Balzac Cousin Bette Lion Feuchtwanger Jew Suess Emile Zola Nana Emile Zola The Belly of Paris Truman Capote In Cold blood Truman Capote Breakfast at Tiffany
Ouput of the program.
DataSet & MySqlDataAdapter
A DataSet is a copy of the data and
the relations among the data from the database tables. It is created
in memory and used when extensive processing on data is needed or
when we bind data tables to a Winforms control. When the processing is
done, the changes are written to the data source. A MySqlDataAdapter
is an intermediary between the DataSet and the data source. It
populates a DataSet and resolves updates with the data source.
Option Strict On
Imports System.Data
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Dim stm As String = "SELECT * FROM Authors"
Try
conn.Open()
Dim da As New MySqlDataAdapter(stm, conn)
Dim ds As New DataSet
da.Fill(ds, "Authors")
Dim dt As DataTable = ds.Tables("Authors")
dt.WriteXml("authors.xml")
For Each row As DataRow In dt.Rows
For Each col As DataColumn In dt.Columns
Console.WriteLine(row(col))
Next
Console.WriteLine("".PadLeft(20, "="))
Next
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
End Module
We print the authors from the Authors table. This time, we use
the MySqlDataAdapter and DataSet
objects.
Dim da As New MySqlDataAdapter(stm, conn)
A MySqlDataAdapter object is created. It takes an SQL
statement and a connection as parameters.
Dim ds As New DataSet da.Fill(ds, "Authors")
We create and fill the DataSet.
Dim dt As DataTable = ds.Tables("Authors")
We get the table called Authors. We have given a
DataSet only one table, but it can contain multiple tables.
dt.WriteXml("authors.xml")
We write the data to an XML file.
For Each row As DataRow In dt.Rows
For Each col As DataColumn In dt.Columns
Console.WriteLine(row(col))
Next
Console.WriteLine("".PadLeft(20, "="))
Next
We display the contents of the Authors table to the
terminal. To traverse the data, we utilize the rows and
columns of the DataTable object.
In the next example, we are going to bind a table to
a Winforms DataGrid control.
Option Strict On
Imports System.Windows.Forms
Imports System.Drawing
Imports System.Data
Imports MySql.Data.MySqlClient
Public Class WinVBApp
Inherits Form
Private dg As DataGrid
Private da As MySqlDataAdapter
Private ds As DataSet
Public Sub New()
Me.Text = "DataGrid"
Me.Size = New Size(350, 300)
Me.InitUI()
Me.InitData()
Me.CenterToScreen()
End Sub
Private Sub InitUI()
dg = New DataGrid
dg.CaptionBackColor = System.Drawing.Color.White
dg.CaptionForeColor = System.Drawing.Color.Black
dg.CaptionText = "Authors"
dg.Location = New Point(8, 0)
dg.Size = New Size(350, 300)
dg.TabIndex = 0
dg.Parent = Me
End Sub
Private Sub InitData()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Dim stm As String = "SELECT * FROM Authors"
ds = New DataSet
Try
conn.Open()
da = New MySqlDataAdapter(stm, conn)
da.Fill(ds, "Authors")
dg.DataSource = ds.Tables("Authors")
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
Finally
conn.Close()
End Try
End Sub
Public Shared Sub Main()
Application.Run(New WinVBApp)
End Sub
End Class
In this example, we bind a Authors table to a Winforms
DataGrid control.
Imports System.Windows.Forms Imports System.Drawing
These two namespaces are for the GUI.
Me.InitUI() Me.InitData()
Inside the InitUI method, we build the user interface.
In the InitData method, we connect to the database,
retrieve the data into the DataSet and bind it to the
DataGrid control.
dg = New DataGrid
The DataGrid control is created.
Dim stm As String = "SELECT * FROM Authors"
We will display the data from the Authors table in the
DataGrid control.
dg.DataSource = ds.Tables("Authors")
We bind the DataSource property of the DataGrid
control to the chosen table.
vbnc -r:/usr/lib/mono/2.0/System.Windows.Forms.dll
-r:/usr/lib/cli/MySql.Data-6.1/MySql.Data.dll grid.vb
To compile the example, we must include two DLLs. The DLL for the Winforms and the DLL for the MySQL connector.
Transaction support
A transaction is an atomic unit of database operations
against the data in one or more databases. The effects of all the SQL
statements in a transaction can be either all committed to the database
or all rolled back.
The MySQL database has different types of storage engines. The most common are the MyISAM and the InnoDB engines. The MyISAM is the default one. There is a trade-off between data security and database speed. The MyISAM tables are faster to process and they do not support transactions. On the other hand, the InnoDB tables are more safe against the data loss. They support transactions. They are slower to process.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Dim cmd As New MySqlCommand()
Dim tr As MySqlTransaction
Try
conn.Open()
tr = conn.BeginTransaction()
cmd.Connection = conn
cmd.Transaction = tr
cmd.CommandText = "UPDATE Authors SET Name = 'Leo Tolstoy' WHERE Id = 1"
cmd.ExecuteNonQuery()
cmd.CommandText = "UPDATE Books SET Title = 'War and Peace' WHERE Id = 1"
cmd.ExecuteNonQuery()
cmd.CommandText = "UPDATE Books SET Titl = 'Anna Karenina' WHERE Id = 2"
cmd.ExecuteNonQuery()
tr.Commit()
conn.Close()
Catch ex As MySqlException
tr.Rollback()
Console.WriteLine("Error: " & ex.ToString())
End Try
End Sub
End Module
In this program, we want to change the name of the author
on the first row of the Authors table. We must also change the
books associated with this author. A good example where a
transaction is necessary. If we change the author and do not
change the author's books, the data is corrupted.
Dim tr As MySqlTransaction
The MySqlTransaction is an object
for working with transactions.
tr = conn.BeginTransaction()
We begin a transaction.
cmd.CommandText = "UPDATE Books SET Titl = 'Anna Karenina' WHERE Id = 2" cmd.ExecuteNonQuery()
The third SQL statement has an error. There is no Titl column in the table.
tr.Commit()
If there is no exception, the transaction is committed.
Catch ex As MySqlException
tr.Rollback()
Console.WriteLine("Error: " & ex.ToString())
In case of an exception, the transaction is rolled back. No changes are committed to the database.
$ ./transaction.exe Error: MySql.Data.MySqlClient.MySqlException: Unknown column 'Titl' in 'field list' at MySql.Data.MySqlClient.MySqlStream.ReadPacket () [0x00000] at MySql.Data.MySqlClient.NativeDriver.ReadResult () [0x00000] mysql> SELECT Name, Title From Authors, Books WHERE Authors.Id=Books.AuthorId; +-------------------+----------------------+ | Name | Title | +-------------------+----------------------+ | Jack London | Call of the Wild | | Jack London | Martin Eden | | Honore de Balzac | Old Goriot | | Honore de Balzac | Cousin Bette | | Lion Feuchtwanger | Jew Suess | | Emile Zola | Nana | | Emile Zola | The Belly of Paris | | Truman Capote | In Cold blood | | Truman Capote | Breakfast at Tiffany | +-------------------+----------------------+ 9 rows in set (0.00 sec)
An exception was thrown. The transaction was rolled back and no changes took place.
However, without a transaction, the data is not safe.
Option Strict On
Imports MySql.Data.MySqlClient
Module Example
Sub Main()
Dim cs As String = "Database=testdb;Data Source=localhost;" _
& "User Id=testuser;Password=test623"
Dim conn As New MySqlConnection(cs)
Dim cmd As New MySqlCommand()
Try
conn.Open()
cmd.Connection = conn
cmd.CommandText = "UPDATE Authors SET Name = 'Leo Tolstoy' WHERE Id = 1"
cmd.ExecuteNonQuery()
cmd.CommandText = "UPDATE Books SET Title = 'War and Peace' WHERE Id = 1"
cmd.ExecuteNonQuery()
cmd.CommandText = "UPDATE Books SET Titl = 'Anna Karenina' WHERE Id = 2"
cmd.ExecuteNonQuery()
conn.Close()
Catch ex As MySqlException
Console.WriteLine("Error: " & ex.ToString())
End Try
End Sub
End Module
We have the same example. This time, without the transaction support.
$ ./update.exe Error: MySql.Data.MySqlClient.MySqlException: Unknown column 'Titl' in 'field list' at MySql.Data.MySqlClient.MySqlStream.ReadPacket () [0x00000] at MySql.Data.MySqlClient.NativeDriver.ReadResult () [0x00000] mysql> SELECT Name, Title From Authors, Books WHERE Authors.Id=Books.AuthorId; +-------------------+----------------------+ | Name | Title | +-------------------+----------------------+ | Leo Tolstoy | War and Peace | | Leo Tolstoy | Martin Eden | | Honore de Balzac | Old Goriot | | Honore de Balzac | Cousin Bette | | Lion Feuchtwanger | Jew Suess | | Emile Zola | Nana | | Emile Zola | The Belly of Paris | | Truman Capote | In Cold blood | | Truman Capote | Breakfast at Tiffany | +-------------------+----------------------+ 9 rows in set (0.00 sec)
An exception is thrown again. Leo Tolstoy did not write Martin Eden. The data is corrupted.
This was the MySQL Visual Basic tutorial, with MySQL Connector. You might be also interested in MySQL C API tutorial, PyMySQL tutorial or PHP mysqli tutorial.