Table of Contents Introduction Why do you want to connect to multiple database Prerequisites Project Setup Application Properties DataSource Configurations DAO Class Source Code Introduction Here I am going to show you how to connect to Oracle data source using JDBC LDAP URL. I am going to create multiple data sources for connecting to multiple Oracle databases using Spring Boot…

You might encounter the following issue while executing an SQL query qith Group By clause in MySQL database server. Error Type: mysqli_sql_exception #1055 Error Details: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘roytuts.visitors.access_date’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

In this example I will show you installing PostgreSQL zip archive in Windows environment. I will show you how to setup username and password for your PostgreSQL database server. I am also going to show you some basic commands for listing all database, switching to another database, creating a new database, showing all tables, creating a new table, database backup,…

This example will show you how to delete or eliminate duplicate records from a table in database. Keeping duplicate records in a table is unnecessary and it also grows the size of database unnecessary. Removing duplicate records from the table will free the occupied space and enhance also the performance of the query execution. Let’s say you have the following…

You are not going to always return records from MongoDB but sometimes you need to perform some computations such as sum, count, average, etc. Here you need the aggregation operations which are used to process data that return the computed results. Therefore aggregation actually groups data from multiple documents and performs a variety of operations on the grouped data to…

You may not want to fetch a whole bunch of data from the document which is stored in a collection in your MongoDB database. You can restrict the number of records or data using different conditions with the help of WHERE, AND, OR and IN operators, but what if you want to restrict the data you want in your particular…

MongoDB is one of the most popular NoSQL database where data are stored in the form of documents. You can also create tables in traditional way to put your structured data but the main purpose is to store unstructured data in the form of object which may vary based on a particular requirement. Now when you select data from collection,…

MongoDB is one of the most popular NoSQL database where your data are stored in a collection. To quickly access your data from MongoDB you can execute commands on MongoDB shell and your results appear based on the given criteria. One of the commands is find() function and using this command you can easily retrieve data from MongoDB collection. When…

Introduction In this tutorial I am going to show you how to work with different changes or versioning maintenance on database scripts without touching the original SQL scripts. So we will only work with the changes we need at a later point of time for our database. Let’s say you have created a table through SQL script using liquibase framework…

Backup and Restore This guide will show you how to backup and restore MySQL database using command line tool in VPS server on CentOS 7 and PhpMyAdmin. You need to take backup of your MySQL database on a daily basis to have minimal impact on your web site’s data loss. Similarly for some inconsistent situations you may need to restore…