跳坑的難受
jdbc那些坑如下
1.注意&分割，報錯很難受
2.注意colse加try{
}catch
不然就會出現你最喜歡的空指標例外
以后遇到將繼續補上
下面展示一下 具體五步走代碼塊，
import java.sql.*;
public class SampleJd {
public static void main(String[] args) {
Connection conn = null;
try {
// 1.加載并且注冊JDBC驅動
Class.forName("com.mysql.jdbc.Driver");
//2.創建資料庫連接
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/tk?useSSL=false&useUnicode&ture&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai", "root", "密碼"
);
//3.創建 Statement物件
Statement stmt = conn.createStatement();
//結果集
ResultSet rs = stmt.executeQuery("select * from ep");
//4.遍歷查詢結果
while (rs.next()) {
Integer eno = rs.getInt(1); //eno 通過欄位獲取
String ename = rs.getString("ename");
Float salary = rs.getFloat("salary");
String dname = rs.getString("dname");
System.out.println(dname + "-" + eno + "-" + salary + "-" + ename);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (conn != null && conn.isClosed() == false) {
//5.關閉連接,釋放資源
conn.close();
}
} catch(Exception ex){
ex.printStackTrace();
}
}
}
}
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