JDBC增删改查操作

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学期末233333

（1）java.sql.Connection: 负责连接数据库。

（2）java.sql.Statement: 负责执行数据库SQL语句。

（3）java.sql.ResultSet: 负责存放查询结果。

添加数据：

public class Insert {public static void main(String args[]) throws Exception {//数据库数据乱码处理String url = "jdbc:mysql://localhost:3306/library?useUnicode=true&characterEncoding=GBK";String user = "root";String password = "123456";Class.forName("com.mysql.jdbc.Driver");Connection conn = DriverManager.getConnection(url, user, password);//添加数据(1)Statement stat = conn.createStatement();String sql = "insert into t_book(bookid, bookname, bookprice) values('0015','数据库原理',32)";int i = stat.executeUpdate(sql);System.out.println("添加"+i+"行数据");stat.close();//添加数据(2)sql = "insert into t_book(bookid,bookname,bookprice) values(?,?,?)";PreparedStatement ps = conn.prepareStatement(sql);ps.setString(1, "0015");ps.setString(2, "JavaEE");ps.setInt(3, 233);i = ps.executeUpdate();System.out.println("添加"+i+"行数据");ps.close();conn.close();}}

删除数据：

public class Delete {public static void main(String args[]) throws Exception {String url = "jdbc:mysql://localhost:3306/library?useUnicode=true&characterEncoding=GBK";String user = "root";String password = "123456";Class.forName("com.mysql.jdbc.Driver");Connection conn = DriverManager.getConnection(url,user,password);//删除数据(1)Statement stat = conn.createStatement();String sql = "delete from t_book where bookid = '0015'";int i = stat.executeUpdate(sql);System.out.println("删除"+i+"行数据");stat.close();//删除数据(2)sql = "delete from t_book where bookid = ?";PreparedStatement ps = conn.prepareStatement(sql);ps.setString(1, "0015");i = ps.executeUpdate();System.out.println("删除"+i+"行数据");ps.close();conn.close();}}

更新数据:

public class Update {public static void main(String args[]) throws Exception {String url = "jdbc:mysql://localhost:3306/library?useUnicode=true&characterEncoding=GBK";String user = "root";String password = "123456";Class.forName("com.mysql.jdbc.Driver");Connection conn = DriverManager.getConnection(url,user,password);//更新数据(1)Statement stat = conn.createStatement();String sql = "update t_book set bookprice = 233 where bookid = 0002";int i = stat.executeUpdate(sql);System.out.println("成功更新"+i+"行数据");stat.close();//更新数据(2)sql = "update t_book set bookprice = ? where bookid = ?";PreparedStatement ps = conn.prepareStatement(sql);ps.setInt(1, 332);ps.setString(2, "0002");i = ps.executeUpdate();System.out.println("成功更新"+i+"行数据");ps.close();conn.close();}}

查询数据:

public class Select {public static void main(String args[]) throws Exception{String url = "jdbc:mysql://localhost:3306/library?useUnicode=true&characterEncoding=GBK";String user = "root";String password = "123456";Class.forName("com.mysql.jdbc.Driver");Connection conn = DriverManager.getConnection(url,user,password);//查询数据(1)Statement stat = conn.createStatement();String sql = "select * from t_book";ResultSet rs = stat.executeQuery(sql);stat.close();//查询数据(2)sql = "select * from t_book where bookid = ?";PreparedStatement ps = conn.prepareStatement(sql);ps.setString(1, "0002");rs = ps.executeQuery();while(rs.next()){String bookid = rs.getString("bookid");String bookname = rs.getString("bookname");int bookprice = rs.getInt("bookprice");System.out.println(bookid+" "+bookname+" "+bookprice);}ps.close();rs.close();conn.close();}}

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