在 Crystal Reports 中创建报表时，在设计报表时，可以通过两种方式访问 MySQL 数据。

第一种方式是在设计报表时使用 Connector/ODBC 作为 ADO 数据源。您将能够浏览数据库并选择表和字段，使用拖放操作来构建报表。这种方法的缺点是必须在应用程序中执行额外的操作，才能生成与报表预期的数据集相匹配的数据集。

第二种方式是在 VB.NET 中创建数据集并将其保存为 XML。然后，此 XML 文件可用于设计报表。在应用程序中显示报表时，这种方式非常有效，但在设计时不太灵活，因为您必须在创建数据集时选择所有相关列。如果您忘记了某个列，则必须重新创建数据集，才能将该列添加到报表中。

以下代码可用于从查询创建数据集并将其写入磁盘

C# 代码示例

DataSet myData = new DataSet();
MySql.Data.MySqlClient.MySqlConnection conn;
MySql.Data.MySqlClient.MySqlCommand cmd;
MySql.Data.MySqlClient.MySqlDataAdapter myAdapter;

conn = new MySql.Data.MySqlClient.MySqlConnection();
cmd = new MySql.Data.MySqlClient.MySqlCommand();
myAdapter = new MySql.Data.MySqlClient.MySqlDataAdapter();

conn.ConnectionString = "server=127.0.0.1;uid=root;" +
  "pwd=12345;database=test";

try
{
  cmd.CommandText = "SELECT city.name AS cityName, city.population AS CityPopulation, " +
  "country.name, country.population, country.continent " +
  "FROM country, city ORDER BY country.continent, country.name";
  cmd.Connection = conn;

  myAdapter.SelectCommand = cmd;
  myAdapter.Fill(myData);

  myData.WriteXml(@"C:\dataset.xml", XmlWriteMode.WriteSchema);
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
  MessageBox.Show(ex.Message, "Report could not be created",
  MessageBoxButtons.OK, MessageBoxIcon.Error);
}

Visual Basic 代码示例

Dim myData As New DataSet
Dim conn As New MySqlConnection
Dim cmd As New MySqlCommand
Dim myAdapter As New MySqlDataAdapter

conn.ConnectionString = "server=127.0.0.1;" _
    & "uid=root;" _
    & "pwd=12345;" _
    & "database=world"

Try
    conn.Open()
    cmd.CommandText = "SELECT city.name AS cityName, city.population AS CityPopulation, " _
        & "country.name, country.population, country.continent " _
        & "FROM country, city ORDER BY country.continent, country.name"
    cmd.Connection = conn

    myAdapter.SelectCommand = cmd
    myAdapter.Fill(myData)

    myData.WriteXml("C:\dataset.xml", XmlWriteMode.WriteSchema)
Catch ex As Exception
    MessageBox.Show(ex.Message, "Report could not be created", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try

生成的 XML 文件在设计报表时可用作 ADO.NET XML 数据源。

如果您选择使用 Connector/ODBC 设计报表，则可以从 dev.mysql.com 下载。