Java PrepareStatement

1.PreparedStatement是预编译的,对于批量处理可以大大提高效率. 也叫JDBC存储过程
2.使用 Statement 对象。在对数据库只执行一次性存取的时侯，用 Statement 对象进行处理。PreparedStatement 对象的开销比Statement大，对于一次性操作并不会带来额外的好处。
3.statement每次执行sql语句，相关数据库都要执行sql语句的编译，preparedstatement是预编译得, preparedstatement支持批处理

用法：

conn = DriverManager.getConnection(url, userName, password); 

//创建PreparedStatement语句
PreparedStatement pstmtDelete = conn.prepareStatement(
"DELETE FROM student WHERE stu_id>=?");
PreparedStatement pstmtInsert = conn.prepareStatement(
"INSERT INTO student VALUES(?, ?, ?, ?)");
PreparedStatement pstmtSelect = conn.prepareStatement(
"SELECT * FROM student WHERE stu_id>=? " +
"ORDER BY stu_id"); 

int Integer.toString(id)); 

//多次执行同一语句
for (int i=0; i<3; i++, id++) { 

//使用setXXX方法设置IN参数
pstmtDelete.setString(1, Integer.toString(id)); 

pstmtInsert.setString(1, Integer.toString(id));
pstmtInsert.setString(2, "name"+id);
pstmtInsert.setString(3, "city"+id);
pstmtInsert.setDate(4, new Date(78, 2, id)); 

//执行PreparedStatement语句
pstmtDelete.executeUpdate();
pstmtInsert.executeUpdate();
ResultSet rs = pstmtSelect.executeQuery(); 

System.out.println("");
System.out.println("第 " + (i+1) + " 次循环后的结果集为："); 

//显示返回的结果集
while (rs.next()) {
String stuID = rs.getString(1);
String String address = rs.getString(3);
String birthday= rs.getString(4);
System.out.println(stuID + " " +
name + " " + address + " " + birthday);
}
} 

pstmtDelete.close();
pstmtInsert.close();
pstmtSelect.close(); 

} catch(SQLException e) {
System.out.println("出现SQLException异常");
} finally {
//关闭语句和数据库连接
try {
if (conn != null) conn.close();
} catch(SQLException e) {
System.out.println("关闭数据库连接时出现异常");
}
} 

}