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💡 概念：JDBC是java提供的一套用于操作資料庫的接口API：java程式員隻需要面向這套接口程式設計即可；
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java連接配接資料庫有五種方式：①靜态加載②使用反射動态加載
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1 JDBC靜态加載，的使用步驟
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1.1 注冊驅動【加載Driver類】
Driver driver = new Driver();
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1.2 擷取連接配接【得到Connection】
Properties properties = new Properties();
String url = "jdbc:mysql://127.0.0.1:3306/school";
properties.setProperty("user","root");
properties.setProperty("password","123456");
Connection connect = driver.connect(url, properties);
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1.3 執行增删改查【發送SQL指令】
String sql = "create table test";
Statement statement = connect.createStatement();
statement.executeUpdate(sql);
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1.4 釋放資源
connect.close();
statement.close();
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2 反射動态加載資料庫
// 方式2 動态加載[使用反射加載driver類]
// 加載driver的Class對象
Class<?> aClass = Class.forName("com.mysql.jdbc.Driver");
Driver driver = (Driver) aClass.newInstance();
// 2得到連接配接
String url = "jdbc:mysql://127.0.0.1:3306/school";
Properties properties = new Properties();
properties.setProperty("user", "root");
properties.setProperty("password", "150896@zsl");
Connection connect = driver.connect(url, properties);
// 3執行SQL
String sql = "delete from person where id = 2";
// 建立statement對象
Statement statement = connect.createStatement();
int i = statement.executeUpdate(sql);
System.out.println(i > 0 ? "成功" : "失敗！");
// 4關閉資源
connect.close();
statement.close();
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3 使用DriverManager統一管理
// 方式3 使用DriverManager注冊驅動，進行統一管理
// 1 注冊驅動
Class<?> aClass = Class.forName("com.mysql.jdbc.Driver");
Driver driver = (Driver) aClass.newInstance();
String url = "jdbc:mysql://localhost:3306/school";
String user = "root";
String password = "150896@zsl";
DriverManager.registerDriver(driver);//注冊driver驅動
// 2擷取Connetion
Connection connection = DriverManager.getConnection(url, user, password);
// 3 執行SQL操作
String sql = "insert into person value (1,'韓順平',99,88,98)";
Statement statement = connection.createStatement();
int i = statement.executeUpdate(sql);
System.out.println(i>0 ? "成功":"失敗");
// 3 關閉資源
connection.close();
statement.close();
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4 推薦使用
// 方式4 使用Class.forName() 自動完成驅動，簡化代碼，
// 1 自動完成驅動注冊
Class<?> aClass = Class.forName("com.mysql.jdbc.Driver");
// 建立url、user 、password
String url = "jdbc:mysql://localhost:3306/school";
String user = "root";
String password = "150896@zsl";
// 2 建立連接配接
Connection connection = DriverManager.getConnection(url, user, password);
// 3 執行SQL
String sql = "insert into person value (2,'zsl',99,88,88)";
Statement statement = connection.createStatement();
int i = statement.executeUpdate(sql);
System.out.println(i>0 ? "成功":"失敗");
// 4 關閉資源
connection.close();
statement.close();
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5 ResultSet類的使用
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5.1 基本介紹
（1）表示資料庫結果集的一個資料表，通常通過執行select語句生成<br />（2）ResultSet保持一個光标，指向目前資料行，最初光标位于第一行之前<br />（3）next方法将光标移到下一行，當在ResultSet對象沒有下一行對象時傳回false
// ResultSet類的使用
// 擷取配置檔案資訊
Properties properties = new Properties();
properties.load(new FileInputStream("src\\mysql.properties"));
String user = properties.getProperty("user");
String password = properties.getProperty("password");
String url = properties.getProperty("url");
String driver = properties.getProperty("driver");
// 1 注冊驅動
Class<?> aClass = Class.forName(driver);
Driver driver1 = (Driver) aClass.newInstance();
// 2 建立連接配接
Connection connection = DriverManager.getConnection(url, user, password);
// 3 執行SQL語句select語句
String sql = "select * from person ";
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(sql);
while (resultSet.next()){
int id = resultSet.getInt(1);
String name = resultSet.getString(2);
int Chinese = resultSet.getInt(3);
System.out.println(id+"\t"+name+"\t"+Chinese);
}
// 4 關閉資源
connection.close();
statement.close();
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6 預處理PreparedStatement,與Statement相比更安全避免了SQL注入
// PreparedStatement預處理使用
Properties properties = new Properties();
properties.load(new FileInputStream("src\\mysql.properties"));
String user = properties.getProperty("user");
String password = properties.getProperty("password");
String url = properties.getProperty("url");
String driver = properties.getProperty("driver");
// 1 注冊驅動
Class<?> aClass = Class.forName(driver);
Driver driver1 = (Driver) aClass.newInstance();
// 2 建立連接配接
Connection connection = DriverManager.getConnection(url, user, password);
// 3 執行SQL語句select語句
String na = "admin";
String pw = "123";
// SQL語句中的？相當與站位符
String selectSql = "select id from user where `name` =? and pwd = ?";
String addSql = "insert into user value('001','admin','123')";
String createTable = "create table user ( id varchar(10),`name` varchar(10),pwd varchar(10))";
PreparedStatement preparedStatement = connection.prepareStatement(selectSql);
preparedStatement.setString(1,na);
preparedStatement.setString(2,pw);
// int i = preparedStatement.executeUpdate();
// System.out.println(i>0? "成功":"失敗");
ResultSet resultSet = preparedStatement.executeQuery();
System.out.println(resultSet);
while (resultSet.next()){
String id = resultSet.getString(1);
System.out.println(id);
}
// 4 關閉資源
connection.close();
preparedStatement.close();
7 JDBC事務處理
8 JDBC的SQL語句批處理
public void batch(){
Connection conection = JDBCUtils.getConection();
String sql = "insert into admain value(?,?,?)";
PreparedStatement preparedStatement = null;
try {
preparedStatement = conection.prepareStatement(sql);
System.out.println("開始執行！");
long starr = System.currentTimeMillis();
for (int i = 0; i <= 1000; i++) {
preparedStatement.setInt(1,i);
preparedStatement.setString(2,"小明"+i);
preparedStatement.setString(3,"123"+i);
// 将SQL語句加入批進行中
preparedStatement.addBatch();
// 當有111條語句時批量執行
if (i%100==0){//執行語句滿111
// 批量執行
preparedStatement.executeBatch();
// 清空
preparedStatement.clearBatch();
}
}
long end = System.currentTimeMillis();
System.out.println("批量處理執行時間："+(end-starr));
} catch (SQLException e) {
e.printStackTrace();
}
JDBCUtils.getClose(preparedStatement,conection,null);
}
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