java.sql.SQLException：未选择数据库 [英] java.sql.SQLException: No database selected

问题描述

如上所述我有一个问题是选择数据库

as above i have a problem to "select the database"

我正在使用xampp，我在MySQL中创建了一个数据库，并将其命名为employees

i am using xampp, there i created a database in MySQL and named it "employees"

这是我的java代码：

This is my java code:

 public static void main(String[] args) {
 Connection conn = null;
 Statement stmt = null;
 try{
  //STEP 2: Register JDBC driver
  Class.forName("com.mysql.jdbc.Driver");

  //STEP 3: Open a connection
  System.out.println("Connecting to database...");
  conn = DriverManager.getConnection("jdbc:mysql://localhost?user=root&password=");

  //STEP 4: Execute a query
  System.out.println("Creating statement...");
  stmt = conn.createStatement();
  String sql;
  sql = "SELECT id, first, last, age FROM employees";
  ResultSet rs = stmt.executeQuery(sql);

如'sql'中所示，我尝试使用 FROM到达数据库员工

As seen in 'sql' I try to reach the database, using FROM employees

我是数据库编程新手。
我需要找到数据库的路径吗？如何以及在哪里可以找到它？

I am new to programming with databases. Do i need to find the path of the database? how and where can i find it?

推荐答案

更改连接字符串以使其连接到localhost上的正确数据库

Change your connection string to make it connect to the right database on localhost

conn = DriverManager.getConnection("jdbc:mysql://localhost/employees?user=root&password=");

或者你可以指定表的完整路径，即数据库.tablename ：

Alternatively you can specify the "full" path to the tables, i.e. database.tablename:

sql = "SELECT id, first, last, age FROM employees.employees";

这篇关于java.sql.SQLException：未选择数据库的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！