In this sample I am using a node module called ‘ ExcelJS‘. This will stream the data to the file instead of big data in memory (if we are keeping large amount of data in memory, we may get JavaScript heap out of memory exception ) this will write to the file
Install the module using npm
|
1 |
npm install exceljs --save |
then in the node application just import the module
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
const Excel = require('exceljs'); const options = { filename: 'myfile.xlsx', useStyles: true, useSharedStrings: true }; const workbook = new Excel.stream.xlsx.WorkbookWriter(options); const worksheet = workbook.addWorksheet('my sheet'); worksheet.columns = [ { header: 'Id', key: 'id' }, { header: 'First Name', key: 'first name' }, { header: 'Phone', key: 'ph' } ] var data; for(let i = 1; i<= 10; i++){ data = { id: i, 'first name': "name "+i, ph: "012014520"+i }; worksheet.addRow(data).commit(); } workbook.commit().then(function() { console.log('excel file cretaed'); }); |
we can use the same module in typescript also
refer : exceljs
Codeigniter create custom config
Create config file in ‘application\config’ folder, give any name (for example I have given ‘cust_settings.php’ [application\config\cust_settings.php] )
|
1 2 3 4 5 6 7 8 9 10 |
<?php if (!defined('BASEPATH')) exit('No direct script access allowed'); $config['site_name'] = 'My website'; $config['protocol'] = 'smtp'; $config['smtp_host'] = 'smtp1.server.com'; $config['smtp_user'] = 'username'; $config['smtp_pass'] = 'password'; $config['smtp_port'] = '25'; |
You can use ‘config->load()’ function to load the configuration and ‘$this->config->item()’ to retrieve the configuration values
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 |
<?php defined('BASEPATH') OR exit('No direct script access allowed'); class Welcome extends CI_Controller { public function index() { // Loads a config file named cust_settings.php and assigns it to an index named "cust_settings" $this->config->load('cust_settings', TRUE); // Retrieve a config item named site_name contained within the cust_settings array $site_name = $this->config->item('site_name', 'cust_settings'); echo $site_name."<br><br>"; // An alternate way to specify the same item: $cust_settings = $this->config->item('cust_settings'); //$site_name = $cust_settings['site_name']; echo "<pre>"; print_r($cust_settings); echo "</pre>"; $this->load->view('welcome_message'); } } |
Output
For using this we can load multiple configuration files
ref: codeigniter.com
In the bellow example, getting list of person id not exist in the given list
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
SELECT E.person_id FROM (VALUES (661), (1826), (2036), (2567), (2922), (3408) ) E(person_id) WHERE NOT EXISTS ( SELECT 1 FROM persontable P WHERE E.person_id = P.id ) |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
SELECT E.email FROM (VALUES ) E(email) WHERE NOT EXISTS ( SELECT 1 FROM person P WHERE E.email = P.emailid ) |
tested in PostgreSQL
Add the following code in function.php to enable session in wordpress
|
1 2 3 4 5 6 7 |
add_action('init', 'activate_session', 1); function activate_session() { if(!session_id()) { session_start(); } } |
This is a basic example for beginners for creating a basic java spring boot application using ‘spring-boot-starter-parent’.
In this tutorial I am using Spring tool suite as my IDE.
I.1: File->New -> Maven Project (You can do it by write clicking in the blank space of Package Explorer )
I.2: I have selected ‘create a simple project ( skip archetye selection)’ this allow me to kip the Archetype selection
I.3 : Setting group id and artifact id and other project related details
Done with the maven project creation, you can see the IDE automatically create the project folder structure like bellow .
You can see the project details in pom.xml file
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mytutor</groupId> <artifactId>my-project</artifactId> <version>0.0.1-SNAPSHOT</version> <name>My Project</name> <description>some description</description> <properties> <java.version>1.8</java.version> <!-- Setting java version --> </properties> <parent> <!-- here we are saying our project is a child of the spring-boot-starter-parent project --> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.3.RELEASE</version> </parent> <dependencies> <dependency> <!-- Adding spring boot dependency --> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> </project> |
write click on project folder->Maven->Update Project
After update we can see JRe updated to 1.8 and added Maven Dependencies
Now we can create our application entry point
Crate a class like bellow (sselect the tic ‘public static void main’ to auto generate the function)
Right click in Package Explorer -> New ->Class
Then add @SpringBootApplication annotation to the class and add SpringApplication.run(MyApp.class, args); inside the main function
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
package com.mytutor; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class MyApp { public static void main(String[] args) { // TODO Auto-generated method stub SpringApplication.run(MyApp.class, args); } } |
Now we can create our controller
Right click in Package Explorer -> New ->Class
Add the following code in the file
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
package com.mytutor.controllers; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class MyFirstController { @RequestMapping("/home") //Request mapping https://localhost/home String myHome() { return "Hello World!"; } } |
You are done
Now we can run our application You can press the Green *Play button 
Or you can right click the project folder and select the Run As – >Java Application
Tadaaaaa! Our project is running
Now we can hit the url
We and run Spring boot application from command line also by using the command mvn spring-boot:run
Done
Note
If you are getting the error “Exception in thread “main” java.lang.NoClassDefFoundError: ch/qos/logback/classic/turbo/TurboFilter ” please add the logback-classic dependency in pom file
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- Exception in thread "main" java.lang.NoClassDefFoundError: ch/qos/logback/classic/turbo/TurboFilter --> <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic --> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.2.3</version> <scope>test</scope> </dependency> </dependencies> |
|
1 |
mvn clean package -DskipTests=true |
|
1 |
mvn clean install -DskipTests=true |