In SQL Server, there are a number of different techniques to combine records into strings. Different methods to combine rows into a string which we will study in this tutorial − COALESCE XML PATH STRING_AGG First approach: COALESCE To combine many rows into a single string using the COALESCE method, first, create a variable of type varchar to hold the coalesced strings, then use a comma to separate each row's string values. Finally, apply the COALESCE to the variable. Syntax Select column_name1, column_name2, .. from table_name Declare @variable1 Varchar(MAX), @variable2 Varchar(MAX), ..; Select @variable1 = COALESCE(@variable1 ... Read More

There is a rising trend toward using unconventional database types in an effort to efficiently accommodate the variety of data and fulfill the growing need for data storage. Relational databases have been the standard for many years. However, as markets evolve and storage costs decline, non-relational databases are becoming popular. Columnar databases are appropriate for this. These NoSQL databases were designed for challenging, intricate queries. Columnar databases, in contrast to relational databases, store data in columns instead of rows. Subgroups are created by combining these columns. This kind of database has movable keys and column names. The amount of rows ... Read More

We shall view a Cassandra Collection Data Types tutorial along our Cassandra trip. In this, we will learn about Cassandra's Collection data type. These are data types in the same sense as arrays and structures in C, C++, etc. In addition, we will talk about the Cassandra Collection Data Types using list, set, and map. Consequently, let's begin with Cassandra Collection Data Types. Collection Data Types for Cassandra In Cassandra, a collection data type is essentially a storage container for several values. Typically, the Cassandra-CQL collection data type is defined by a single variable. This variable itself has a range ... Read More

A deductive database in SQL or any other database system is a tool that can draw conclusions about new facts based on the rules and information already present in the database. In deductive databases, datalog is the language commonly used to express facts, rules, and queries. The formula, when expressed in clausal form, consists of a number of clauses, each of which is made up of a number of literals joined exclusively by logical connectives marked with the OR symbol. The following quantifiers are possible in a formula − Universal quantifier − It may be read as "For all x, ... Read More

The handling of missing or incorrect values in queries that change the data is governed by MySQL Strict Mode. This contains the CREATE TABLE, UPDATE, and INSERT statements. When attempting to process the query with MySQL Strict Mode enabled, which is the default setting, invalid or missing data may result in warnings or failures. When Strict Mode is turned off, the identical query would have its missing or incorrect data modified and would result in a straightforward warning. This could appear to be the desired outcome, but with Strict Mode turned off, certain activities might have unanticipated effects. For instance, ... Read More

In this article, we are going to learn about collecting Mysql statistics and Metrics. Performance Dashboard View statistics about server performance in a dashboard. Open a query tab, choose the Management tab, and then click Dashboard in the Performance section of the Navigator sidebar to display the dashboard. The informational structure of the Administration - Dashboard tab is depicted in the following image. Performance: Dashboard Network Status This displays data on network traffic that the MySQL server has transmitted and received via client connections. The incoming network traffic, outgoing network traffic, and client connections are examples of data ... Read More

MS Access is a powerful database management system that allows users to easily organize, store, and manipulate large amounts of data. Among the many built-in functions that MS Access offers, the Chr() and Asc() functions are particularly useful when working with strings. In this article, we will take a closer look at these functions, including what they do, how to use them, and real-life examples of when they can be applied. Understanding the Chr() Function The Chr() function in MS Access is used to return the character that corresponds to a specific ASCII value. The function takes a single argument, ... Read More

Introduction A checkpoint in a database management system (DBMS) is a process that saves the current state of the database to disk. This allows for faster recovery in the event of a system failure or crash. In this article, we will explore the concept of checkpoints in DBMS, including how they work, the different types of checkpoints, and their real-world applications. What is a Checkpoint? A checkpoint is a process that saves the current state of the database to disk. This includes all transactions that have been committed, as well as any changes that have been made to the database ... Read More

Introduction Apache Cassandra is a highly-scalable, high-performance distributed database that is designed to handle large amounts of data across many commodity servers. As a result, it's important to keep an eye on the health of your Cassandra cluster to ensure that it's running smoothly and that there aren't any issues that could impact performance or availability. In this article, we'll go over the different ways to check the health of your Cassandra cluster and what to look for to identify potential issues. Understanding Cassandra Cluster Health Before diving into how to check the health of your Cassandra cluster, it's important ... Read More

Introduction Oracle is a powerful, versatile relational database management system that is widely used in the enterprise. One of the most common tasks when working with Oracle is to check if a specific object, such as a table, view, trigger, or other types of object, exists in the database. This can be useful for a variety of purposes, such as validating input data, checking for dependencies, and more. In this article, we will explore several methods for checking if a table, view, trigger, or other object exists in Oracle. Using the "DBA_OBJECTS" View One of the easiest and most straightforward ... Read More