具有數(shù)據(jù)庫管理員權(quán)限，以在給定模式的數(shù)據(jù)庫表中刪除數(shù)據(jù)記錄。要執(zhí)行以下示例，需要用實(shí)際用戶名和密碼替換這里用戶名(username)和密碼(password)。
MySQL或數(shù)據(jù)庫已啟動并運(yùn)行。

注意：在執(zhí)行刪除數(shù)據(jù)記錄時，需要注意的是數(shù)據(jù)刪除后無法恢復(fù)，所以在刪除數(shù)據(jù)之后必須要確認(rèn)要刪除的數(shù)據(jù)。

所需步驟

使用JDBC應(yīng)用程序刪除表中數(shù)據(jù)記錄需要以下步驟：

導(dǎo)入包：需要包含包含數(shù)據(jù)庫編程所需的JDBC類的包。大多數(shù)情況下，使用import java.sql.*就足夠了。
注冊JDBC驅(qū)動程序：需要初始化驅(qū)動程序，以便可以程序中打開數(shù)據(jù)庫的通信通道。
打開連接：需要使用DriverManager.getConnection()方法來創(chuàng)建一個Connection對象，它表示與數(shù)據(jù)庫服務(wù)器的物理連接。
執(zhí)行查詢：需要使用類型為Statement的對象來構(gòu)建和提交SQL語句，以從表中刪除符合指定條件記錄。查詢語句中可使用WHERE子句來指定刪除記錄的條件。
清理環(huán)境：需要明確地關(guān)閉所有數(shù)據(jù)庫資源，而不依賴于JVM的垃圾收集。

示例代碼

復(fù)制以下示例代碼保存到文件：DeleteRecords.java中，然后編譯并運(yùn)行如下 -

//STEP 1. Import required packages
// See more detail at http://www.yiibai.com/jdbc/


import java.sql.*;

public class DeleteRecords {
   // JDBC driver name and database URL
   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
   static final String DB_URL = "jdbc:mysql://localhost/jdbc_db";

   //  Database credentials
   static final String USER = "root";
   static final String PASS = "123456";

   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 a selected database...");
      conn = DriverManager.getConnection(DB_URL, USER, PASS);
      System.out.println("Connected database successfully...");

      //STEP 4: Execute a query
      System.out.println("Creating statement...");
      stmt = conn.createStatement();
      String sql = "DELETE FROM student " +
                   "WHERE id = 101";
      stmt.executeUpdate(sql);

      // Now you can extract all the records
      // to see the remaining records
      sql = "SELECT id, first, last, age FROM student";
      ResultSet rs = stmt.executeQuery(sql);

      while(rs.next()){
         //Retrieve by column name
         int id  = rs.getInt("id");
         int age = rs.getInt("age");
         String first = rs.getString("first");
         String last = rs.getString("last");

         //Display values
         System.out.print("ID: " + id);
         System.out.print(", Age: " + age);
         System.out.print(", First: " + first);
         System.out.println(", Last: " + last);
      }
      rs.close();
   }catch(SQLException se){
      //Handle errors for JDBC
      se.printStackTrace();
   }catch(Exception e){
      //Handle errors for Class.forName
      e.printStackTrace();
   }finally{
      //finally block used to close resources
      try{
         if(stmt!=null)
            conn.close();
      }catch(SQLException se){
      }// do nothing
      try{
         if(conn!=null)
            conn.close();
      }catch(SQLException se){
         se.printStackTrace();
      }//end finally try
   }//end try
   System.out.println("Goodbye!");
}//end main
}//end JDBCExample

編譯上面代碼，如下 -

F:\worksp\jdbc> javac -Djava.ext.dirs=F:\worksp\jdbc\libs DeleteRecords.java

執(zhí)行上面代碼，如下 -

## 可先創(chuàng)建表或插入數(shù)據(jù) -
## F:\worksp\jdbc> java -Djava.ext.dirs=F:\worksp\jdbc\libs InsertRecords

F:\worksp\jdbc>java -Djava.ext.dirs=F:\worksp\jdbc\libs DeleteRecords
Connecting to a selected database...
Thu Jun 01 23:38:33 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Connected database successfully...
Creating statement...
ID: 100, Age: 22, First: C++, Last: Li
ID: 102, Age: 30, First: Ruby, Last: Ru
ID: 103, Age: 28, First: Java, Last: Ja
Goodbye!

F:\worksp\jdbc>

在執(zhí)行上面語句后，可以看到 ID 為 101的這條記錄已經(jīng)被刪除了。

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