JavaScript usage examples for adding, deleting, modifying and checking web page nodes
The example in this article describes the usage of Javascript for adding, deleting, modifying and checking web page nodes. Share it with everyone for your reference. The specific analysis is as follows: 1. Basic concepts This part is the so-called “HTML DOM”. The so-called HTML DOM is the Web page loading rule. It is a rule, which is the basic formula for the composition of a web page. That is, all web pages must be written according to the rules of:… and loaded according to such rules. The so-called “web page node” is also called the popular explanation of “DOM node”. For example, the content under the html node is all the content between them, and the content under the body node is all the content between them. HTML DOM is stipulated as follows: 1. The entire document is a document node; 2. Each HTML tag (meaning html tags such as , not just tags) is an element node; 3. Contained in The text in HTML elements is text nodes; 4. Each HTML attribute is an attribute node For example, a page can be drawn as the following DOM node tree: The official definition of HTML DOM is as follows:…
Some uncommon tips for adding, deleting, modifying and checking sqlserver
An Insert statement 1. Insert only default values into the data: insert into [DBTrain].[dbo].[log_info] default values 2. In a field that can be null, if you want to set null, you can press [Ctrl+0]. Note that it is zero, not o. If you want to restore the value before modification, press [Esc] Two Update statements You can update the first few items or a certain percentage of data update top(3) [log_info] set info1 = ‘1001’ update top(80) percent [log_info] set info2 = ‘1002’ Three Delete statements can also use the top keyword Four Select statements 1. With Ties Execute the following sql: select top 5 * from test order by id desc The results are shown below: Execute the following sql again to see the difference: select top 5 with ties * from test order by id desc It can be seen that the current five records have not completely displayed the data of id = 2, Use with ties to display all records with id = 2 To be continued. $identity, $RowGuid,Write clause
JavaWeb——A case of adding, deleting, modifying and checking under MVC mode
Directory MVC mode Environment configuration pom.xml mybatis-config. xml Directory structure java directory： com directory： mapper directory： pojo directory： service directory： util directory： web directory： ; resources directory： com/mapper directory： BrandMapper.xml webapp directory&# xff1a; index.html brand.jsp addBrand.jsp updateBrand.jsp MVC mode Environment configuration pom.xml 4.0.0com.myprojectbrand-demo1.0-SNAPSHOTwarmysqlmysql-connector-java8.0.21org.mybatismybatis 3.4.6javax.servletjavax.servlet-api3.1.0provided org.apache.mavenmaven-plugin-api2.0 commons-iocommons-io2.6javax.servlet.jspjsp-api2.1providedjstljstl1.2 org.apache.tomcat.maventomcat7-maven-plugin2.2 mybatis-config.xml Directory structure java directory： com directory： mapper directory： package com.mapper;import com.pojo.Brand;import java.util.List;public interface BrandMapper {List selectAll();void add(Brand brand);Brand selectById(int id);void update(Brand brand);void deletet(int id);} pojo directory： package com.pojo;/*** Brand entity class*/public class Brand {// id primary key private Integer id; // Brand name private String brandName; // Company name private String companyName; // Sorting field private Integer ordered; // Description information private String description; // Status ：0：Disabled 1：Enable private Integer status;public Brand() {}public Brand(Integer id, String brandName, String companyName, String description) {this.id = id;this.brandName = brandName;this .companyName = companyName;this.description = description;} public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {this.id = id;this .brandName = brandName;this.companyName = companyName;this.ordered = ordered;this.description = description;this.status = status;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBrandName() {return brandName;}public void setBrandName(String brandName) {this.brandName = brandName;}public String getCompanyName() {return companyName;}public void setCompanyName(String companyName) {this.companyName = companyName;}public Integer getOrdered() {return ordered;}public…
Some uncommon tips for adding, deleting, modifying and checking sqlserver
An Insert statement 1. Insert only default values into the data: insert into [DBTrain].[dbo].[log_info] default values 2. In a field that can be null, if you want to set null, you can press [Ctrl+0]. Note that it is zero, not o. If you want to restore the value before modification, press [Esc] Two Update statements You can update the first few items or a certain percentage of data update top(3) [log_info] set info1 = ‘1001’ update top(80) percent [log_info] set info2 = ‘1002’ Three Delete statements can also use the top keyword Four Select statements 1. With Ties Execute the following sql: select top 5 * from test order by id desc The results are shown below: Execute the following sql again to see the difference: select top 5 with ties * from test order by id desc It can be seen that the current five records have not completely displayed the data of id = 2, Use with ties to display all records with id = 2 To be continued. $identity, $RowGuid,Write clause
JavaWeb——A case of adding, deleting, modifying and checking under MVC mode
Directory MVC mode Environment configuration pom.xml mybatis-config. xml Directory structure java directory： com directory： mapper directory： pojo directory： service directory： util directory： web directory： ; resources directory： com/mapper directory： BrandMapper.xml webapp directory&# xff1a; index.html brand.jsp addBrand.jsp updateBrand.jsp MVC mode Environment configuration pom.xml 4.0.0com.myprojectbrand-demo1.0-SNAPSHOTwarmysqlmysql-connector-java8.0.21org.mybatismybatis 3.4.6javax.servletjavax.servlet-api3.1.0provided org.apache.mavenmaven-plugin-api2.0 commons-iocommons-io2.6javax.servlet.jspjsp-api2.1providedjstljstl1.2 org.apache.tomcat.maventomcat7-maven-plugin2.2 mybatis-config.xml Directory structure java directory： com directory： mapper directory： package com.mapper;import com.pojo.Brand;import java.util.List;public interface BrandMapper {List selectAll();void add(Brand brand);Brand selectById(int id);void update(Brand brand);void deletet(int id);} pojo directory： package com.pojo;/*** Brand entity class*/public class Brand {// id primary key private Integer id; // Brand name private String brandName; // Company name private String companyName; // Sorting field private Integer ordered; // Description information private String description; // Status ：0：Disabled 1：Enable private Integer status;public Brand() {}public Brand(Integer id, String brandName, String companyName, String description) {this.id = id;this.brandName = brandName;this .companyName = companyName;this.description = description;} public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {this.id = id;this .brandName = brandName;this.companyName = companyName;this.ordered = ordered;this.description = description;this.status = status;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBrandName() {return brandName;}public void setBrandName(String brandName) {this.brandName = brandName;}public String getCompanyName() {return companyName;}public void setCompanyName(String companyName) {this.companyName = companyName;}public Integer getOrdered() {return ordered;}public…
Some uncommon tips for adding, deleting, modifying and checking sqlserver
An Insert statement 1. Insert only default values into the data: insert into [DBTrain].[dbo].[log_info] default values 2. In a field that can be null, if you want to set null, you can press [Ctrl+0]. Note that it is zero, not o. If you want to restore the value before modification, press [Esc] Two Update statements You can update the first few items or a certain percentage of data update top(3) [log_info] set info1 = ‘1001’ update top(80) percent [log_info] set info2 = ‘1002’ Three Delete statements can also use the top keyword Four Select statements 1. With Ties Execute the following sql: select top 5 * from test order by id desc The results are shown below: Execute the following sql again to see the difference: select top 5 with ties * from test order by id desc It can be seen that the current five records have not completely displayed the data of id = 2, Use with ties to display all records with id = 2 To be continued. $identity, $RowGuid,Write clause
