Question

我正在研究数据库我在Eclipse Luna IDE中创建了一个项目。我的数据库是在mysql中。我下载了connector / j文件并将此jar文件添加到我的项目中。这是jar文件的全名＆＃34; mysql-connector-java-5.1.35-bin.jar＆＃34;。但是当我运行该项目时，它将显示此错误消息＆＃34;没有为jdbc找到合适的驱动程序：mysql // localhost / books＆＃34;。 books是我的数据库名称。这是我的java代码。

import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.DriverManager;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

public class DisplayAuthors {


    static final String DATABASE_URL = "jdbc:mysql//localhost/books";

    public static void main(String[] args)  {

        Connection connection = null;
        Statement statement = null;
        ResultSet resultSet = null;

        try {


            connection = DriverManager.getConnection( DATABASE_URL, "saadi", "saadi" );

            statement = connection.createStatement();

            resultSet = statement.executeQuery( "SELECT AuthorID, FirstName, LastName FROM Authors" );

            ResultSetMetaData metaData = resultSet.getMetaData();
            int numberOfColumns = metaData.getColumnCount();
            System.out.println( "Authors Table of Book Database:\n" );

            for ( int i = 1; i < numberOfColumns; i++ ) 
                System.out.printf( "%-8s\t", metaData.getColumnName( i ) );
            System.out.println();

            while ( resultSet.next() ) {
                for ( int i = 1; i <= numberOfColumns; i++ ) 
                    System.out.printf( "%-8s\t", resultSet.getObject( i ) );
                System.out.println();
            }
        }

        catch ( SQLException exception ) {
            exception.printStackTrace();
        }

        finally {
            try {
                resultSet.close();
                statement.close();
                connection.close();
            }

            catch ( Exception exception ) {
                exception.printStackTrace();
            }
        }
    }

}

Answer 1

You have an error in the

DATABASE_URL = "jdbc:mysql//localhost/books"

: is missing .Correct one is

DATABASE_URL = "jdbc:mysql://localhost/books"

Also its kind of usual practice to first load the class before connection manager.

Class.forName("com.mysql.jdbc.Driver");

mysql jdbc驱动程序没有用

1 个答案: