JDBC如何获取mysql的所有数据库的名字？

[qq_24683975]

我的代码是这个

import java.sql.*;
public class Demo1 {
    private static String url="jdbc:mysql://localhost:3306/";
    private static String user="root";
    private static String pwd="";
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        String sql;
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn=DriverManager.getConnection(url,user,pwd);
        Statement stmt=conn.createStatement();
        ResultSet rs=stmt.executeQuery("show databases");
        ResultSetMetaData rs_metaData=rs.getMetaData();
        while (rs.next()){
            int count=rs_metaData.getColumnCount();
            for (int i = 0; i < count; i++) {
                System.out.println(rs_metaData.getColumnName(i + 1));
            }
        }
    }
}

执行结果是
SCHEMA_NAME
SCHEMA_NAME
SCHEMA_NAME
SCHEMA_NAME
实际上有这几个数据库

请问应该如何操作？

[rumlee]

import java.sql.*;
public class Demo1 {
private static String url = "jdbc:mysql://localhost:3306/";
	private static String user = "root";
	private static String pwd = "pass";

	public static void main(String[] args) throws ClassNotFoundException, SQLException {
		String sql;
		Class.forName("com.mysql.jdbc.Driver");
		Connection conn = DriverManager.getConnection(url, user, pwd);
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("show databases");
		ResultSetMetaData rs_metaData = rs.getMetaData();

		while (rs.next()) {
			int count = rs_metaData.getColumnCount();
			for (int i = 0; i < count; i++) {
				System.out.println(rs.getString(i + 1));
			}
		}
	}
}

[老紫竹]

ResultSet rs=stmt.executeQuery("show databases"); 这结果集的第一列，就是库名，你直接 rs.next rs.getString(1) 就行了，还折腾什么metadata干嘛？

[KeepSayingNo]

断点看看ResultSet 这个对象里面的结构，然后取出你想要的数据

[qq_24683975]

引用 2 楼 老紫竹 的回复:

ResultSet rs=stmt.executeQuery("show databases"); 这结果集的第一列，就是库名，你直接 rs.next rs.getString(1) 就行了，还折腾什么metadata干嘛？

啊不好意思因为我刚刚接触jdbc，很多都不会，正在学习！谢谢大家！！

[qq_24683975]

引用 1 楼 rumlee 的回复:

import java.sql.*;
public class Demo1 {
private static String url = "jdbc:mysql://localhost:3306/";
	private static String user = "root";
	private static String pwd = "pass";

	public static void main(String[] args) throws ClassNotFoundException, SQLException {
		String sql;
		Class.forName("com.mysql.jdbc.Driver");
		Connection conn = DriverManager.getConnection(url, user, pwd);
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("show databases");
		ResultSetMetaData rs_metaData = rs.getMetaData();

		while (rs.next()) {
			int count = rs_metaData.getColumnCount();
			for (int i = 0; i < count; i++) {
				System.out.println(rs.getString(i + 1));
			}
		}
	}
}

谢谢大佬！！搞定了，刚刚学习jdbc很多都还不懂