Question

尝试连接sql数据库和Java代码，但出现找不到驱动程序的错误。我已将连接器下载到相应的文件夹中，但找不到问题

我尝试跑步： java -cp。; C：\ asd \ mysql-connector-java-8.0.16 \ mysql-connector-java-8.0.16.jar JdbcSelectTest

通过命令行，但它给了我错误

import java.sql.*;  // Using 'Connection', 'Statement' and 'ResultSet' classes in java.sql package

public class JdbcSelectTest {   // Save as "JdbcSelectTest.java"
   public static void main(String[] args) {
      try (
         // Step 1: Allocate a database 'Connection' object
         Connection conn = DriverManager.getConnection(
               "jdbc:mysql://localhost:3306/ebookshop?allowPublicKeyRetrieval=true&useSSL=false&serverTimezone=UTC",
               "myuser", "xxxx");   // For MySQL only
               // The format is: "jdbc:mysql://hostname:port/databaseName", "username", "password"

         // Step 2: Allocate a 'Statement' object in the Connection
         Statement stmt = conn.createStatement();
      ) {
         // Step 3: Execute a SQL SELECT query. The query result is returned in a 'ResultSet' object.
         String strSelect = "select title, price, qty from books";
         System.out.println("The SQL statement is: " + strSelect + "\n"); // Echo For debugging

         ResultSet rset = stmt.executeQuery(strSelect);

         // Step 4: Process the ResultSet by scrolling the cursor forward via next().
         //  For each row, retrieve the contents of the cells with getXxx(columnName).
         System.out.println("The records selected are:");
         int rowCount = 0;
         while(rset.next()) {   // Move the cursor to the next row, return false if no more row
            String title = rset.getString("title");
            double price = rset.getDouble("price");
            int    qty   = rset.getInt("qty");
            System.out.println(title + ", " + price + ", " + qty);
            ++rowCount;
         }
         System.out.println("Total number of records = " + rowCount);

      } catch(SQLException ex) {
         ex.printStackTrace();
      }  // Step 5: Close conn and stmt - Done automatically by try-with-resources (JDK 7)

我期望数据库能够连接，感谢您的帮助！我认为该错误与第8行的输入有关

Answer 1

您必须在库中包含Driver jar。我正在使用此“ mysql-connector-java-8.0.15.jar”。

参考Where can I download mysql jdbc jar from?

https://repo1.maven.org/maven2/mysql/mysql-connector-java/

将文件放入您的类路径。

不断获取java.sql.SQLException：没有合适的驱动程序，错误，但是我的连接器在正确的文件夹中

1 个答案: