預編譯

package csdn.prepare.take;import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException;public class TestCompiling {public static void main(String[] args) {prepare();}public static void prepare() {Connection conn = null;PreparedStatement ps = null;ResultSet rs = null;try {Class.forName("oracle.jdbc.OracleDriver");String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";conn = DriverManager.getConnection(url, "scott", "scott");String sql = "select * from Users where UNAME = ? and UPASS = ?";// 預編譯命令對象。 ps = conn.prepareStatement(sql);// 給sql里面的？賦值 // 這里有一個sql注入 ps.setString(1, "'123' or 1=1 --");ps.setString(2, "456");/*ps.setString(1, "rye");ps.setString(2, "999");*/// 這里易錯 ps 繼承了父類的 executeUpdate(sql)rs = ps.executeQuery();if (rs.next())System.out.println("登錄成功");else System.out.println("登錄失敗");} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();} finally {try {if (rs != null)rs.close();if (ps != null)ps.close();if (conn != null)conn.close();} catch (SQLException e) {e.printStackTrace();}}}}

批處理

package csdn.prepare.take;import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException;public class TestBatch {public static void main(String[] args) {// 批處理 和 預編譯。batch();//批處理就是把多條數據打包好, 再把數據一次性放入SQL里面。}public static void batch() {Connection conn = null;PreparedStatement ps = null;try {Class.forName("oracle.jdbc.OracleDriver");String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";long start = System.currentTimeMillis();conn = DriverManager.getConnection(url, "scott", "scott");String sql = "insert into Users values (?, ?, ?)";// 預編譯對象ps = conn.prepareStatement(sql);// 我要添加多個對象 用到批處理for (int i = 4; i < 1000000; i++) {ps.setInt(1, i);ps.setString(2, "" + i);ps.setString(3, "" + i); // 把一條SQL語句添加到批處理命令中。ps.addBatch();} // 預編譯對象執行批處理 返回int數組int[] batchs = ps.executeBatch();long end = System.currentTimeMillis();System.out.println("用時" + (end - start) + "毫秒");System.out.println(batchs.length);} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();} finally {try {if (ps != null)ps.close();if (conn != null)conn.close();} catch (SQLException e) {e.printStackTrace();}}}}

users表結構如下

插入了999996條數據 用了

如果比直接插入不用批處理和預編譯快多了。

總結

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