package com.bjsxt;
import java.sql.*;
public class JdbcText {
//插入数据库信息
public void insertdepartment(String department_name , int location_id){
Connection conn=null;
Statement state=null;
try {
conn = JdbcUilt.getConnection();
String sql ="insert into departments values(default,'"+department_name+"',"+location_id+")";
state = conn.createStatement();
System.out.println(state.executeUpdate(sql));
} catch (Exception e) {
e.printStackTrace();
}finally {
JdbcUilt.closeZong(state,conn,null);
}
}
//修改数据库信息
public void Updatedepartment(String department_name , int location_id , int department_id){
Connection conn = null;
Statement state = null;
try{
conn = JdbcUilt.getConnection();
state = conn.createStatement();
String sql = "update departments d set d.department_name='"+department_name+"',d.location_id="+location_id+" where d.department_id="+department_id+"";
System.out.println(state.executeUpdate(sql));
}catch (Exception e){
e.printStackTrace();
}finally {
JdbcUilt.closeZong(state , conn,null);
}
}
//创建查询方法
public void selectdepartment(int department_id){
Connection conn = null;
Statement state = null;
ResultSet rs = null;
try{
conn = JdbcUilt.getConnection();
state = conn.createStatement();
String sql = "select * from departments where department_id"+department_id;
rs = state.executeQuery(sql);
while (rs.next()){
System.out.println(rs.getInt("department_id")+" "+rs.getString("department_name")+" "+rs.getInt(3));
}
}catch (Exception e){
e.printStackTrace();
}finally {
JdbcUilt.closeZong(state , conn,rs);
}
}
public static void main(String[] args) {
JdbcText jb = new JdbcText();
//jb.Updatedepartment("教育部",6,6);
jb.selectdepartment(6);
}
}Wed Jul 28 18:04:16 CST 2021 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.
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'department_id6' in 'where clause'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3978)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3914)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2491)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2449)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1381)
at com.bjsxt.JdbcText.selectdepartment(JdbcText.java:45)
at com.bjsxt.JdbcText.main(JdbcText.java:59)
请问老师我这个报错怎么解决？
老师，这个监听器是监视HttpSession的创建的，为什么这里还需要自己创建HttpSession呢
老师，我添加不了非空约束
老师我这个reader为啥是红的
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