删除子父节点中的某个节点

叁歲伎倆 2022-03-29 06:28 309阅读 0赞

import java.sql.Connection;  
import java.sql.ResultSet;  
import java.sql.SQLException;  
import java.sql.Statement;  
  
  
public class deleteNoteMysql \{  
  
  
public static void main(String args\[\]) throws SQLException \{  
Connection conn = DB.getConn();  
Statement stmt = conn.createStatement();  
ResultSet rs = null;  
int id = 33;  
rs = stmt.executeQuery("select \* from category where id=33");  
rs.next();  
int a = rs.getInt(7);  
int pidd = rs.getInt(2);  
if (pidd == 0) \{  
de(id, a);  
\} else \{  
de(id, a);  
rs = stmt.executeQuery("select count(\*)  from category where pid ="  
\+ pidd);  
System.out.println("pidd=" + pidd);  
rs.next();  
int count = rs.getInt(1);  
if (count <= 0) \{  
stmt.executeUpdate("update category set isLeaf=0 where id= "  
\+ pidd);  
\}  
\}  
System.out.println(a);  
\}  
  
  
private static void de(int id, int isleaf) throws SQLException \{//如果删除的节点的父节点没有其他节点需要设置父节点的idLeaf为0  
// TODO Auto-generated method stub  
Connection conn = DB.getConn();  
Statement st = conn.createStatement();  
if (isleaf == 0) \{  
  
  
st.execute("delete from category where id =" + id);  
\} else \{  
ResultSet rs = st  
.executeQuery("select \*  from category where pid =" + id);  
while (rs.next()) \{  
System.out.println(rs.getInt(1));  
de(rs.getInt(1), rs.getInt(7));  
\}  
st.execute("delete from category where id =" + id);  
\}  
\}  
\}  
  
  
  
  
  
  
  
  
/\*  
import java.sql.\*;  
  
  
public class DB \{  
public static Connection getConn() \{  
Connection conn = null;  
try \{  
Class.forName("com.mysql.jdbc.Driver");  
conn = DriverManager.getConnection("jdbc:mysql://localhost/shopping?user=root&password=admin");  
\} catch (ClassNotFoundException e) \{  
e.printStackTrace();  
\} catch (SQLException e) \{  
e.printStackTrace();  
\}  
  
return conn;  
\}  
\}  
\*/  
/\*  
Navicat MySQL Data Transfer  
  
  
Source Server         : root  
Source Server Version : 50527  
Source Host           : localhost:3306  
Source Database       : shopping  
  
  
Target Server Type    : MYSQL  
Target Server Version : 50527  
File Encoding         : 65001  
  
  
Date: 2013-02-23 10:53:44  
  
  
  
  
SET FOREIGN\_KEY\_CHECKS=0;  
  
  
\-- ----------------------------  
\-- Table structure for \`category\`  
\-- ----------------------------  
DROP TABLE IF EXISTS \`category\`;  
CREATE TABLE \`category\` (  
  \`id\` int(11) NOT NULL AUTO\_INCREMENT,  
  \`pid\` int(11) DEFAULT NULL,  
  \`name\` varchar(255) DEFAULT NULL,  
  \`descr\` varchar(255) DEFAULT NULL,  
  \`cno\` int(11) DEFAULT NULL,  
  \`grade\` int(11) DEFAULT NULL,  
  \`isLeaf\` int(1) NOT NULL,  
  PRIMARY KEY (\`id\`)  
) ENGINE=InnoDB AUTO\_INCREMENT=41 DEFAULT CHARSET=utf8;  
  
  
\-- ----------------------------  
\-- Records of category  
\-- ----------------------------  
INSERT INTO \`category\` VALUES ('31', '0', 'a', 'a', '2147483647', '1', '1');  
INSERT INTO \`category\` VALUES ('32', '0', 'b', 'b', '-2', '1', '1');  
INSERT INTO \`category\` VALUES ('33', '32', 'aa', 'aa', '2147483645', '2', '1');  
INSERT INTO \`category\` VALUES ('34', '33', 'aaa', 'fahdgjhdfjkgjkl', '-4', '3', '1');  
INSERT INTO \`category\` VALUES ('35', '34', 'aaaa', 'aaaa', '2147483643', '4', '0');  
INSERT INTO \`category\` VALUES ('36', '31', 'afgas', 'asg', '-2', '2', '1');  
INSERT INTO \`category\` VALUES ('37', '36', 'asg', 'asfhsdh', '2147483645', '3', '0');  
INSERT INTO \`category\` VALUES ('38', '36', '', '', '-4', '3', '0');  
INSERT INTO \`category\` VALUES ('39', '31', 'dh', 'fdgjhfd', '2147483645', '2', '0');  
INSERT INTO \`category\` VALUES ('40', '31', 'dfgh', 'dfjhdfj', '-4', '2', '0');  
\*/