SQL

SQL joins are used to combine rows from two or more tables based on a related column between them. They are essential for querying relational databases and retrieving comprehensive data sets from multiple tables. Types of SQL Joins: 1. INNER JOIN Purpose: Returns only the rows that have matching values in both tables. Let’s have […]

📊 Mastering SQL Aggregate Functions 📊 SQL aggregate functions are essential for performing calculations on multiple rows of data. They are often used with the GROUP BY clause to provide summaries and insights into data sets. Key SQL Aggregate Functions: Using Aggregate Functions with GROUP BY: To gain more detailed insights, aggregate functions are often

SQL ORDER BY The ORDER BY keyword in SQL is used to sort the result set of a query by one or more columns. Sorting can be done in ascending order (default) or descending order, allowing for easier data analysis and more meaningful reporting. ✅ Syntax of the ORDER BY Keyword Basic Example Consider a table called Employees with the

SQL offers several conditional clauses that help filter data based on specific criteria. These clauses include IS NULL, LIKE, IN, BETWEEN, NOT BETWEEN, and combinations such as BETWEEN with IN. Key Points and Examples: 1. IS NULL The IS NULL clause is used to check for null values in a column. ✅ Basic Syntax: 💡 Example: Retrieve all employees with no assigned department: 2. LIKE The LIKE clause is used for

Understanding SQL Statements SQL statements are the specific queries or operations entered into the database using the SQL language. They are used to access, modify, or manage data stored in database tables. SQL statements consist of keywords, expressions, clauses, and operators. Components of SQL Statements: SELECT Statement The SELECT statement is used to choose data from a

SQL Syntax SQL syntax refers to the set of rules that dictate how SQL statements are constructed. This language is primarily used to interact with relational databases, allowing users to perform operations such as creating, reading, updating, and deleting data within a database. The fundamental structure of a SQL statement typically follows this format: For

SQL (Structured Query Language) was specifically created for managing and manipulating relational databases. It offers commands and statements that enable users to connect to databases, retrieve and update data, design database structures, and execute a variety of data-related tasks. Further information is provided below: Definition and Purpose of SQL: SQL, or Structured Query Language, is

What is Normalisation ? Normalization of data in a database is a process designed to ensure data integrity by eliminating duplication. This involves dividing the database into multiple tables and creating linkages between them. There are various levels of normalization, including First Normal Form (1NF), Second Normal Form (2NF), Third Normal Form (3NF), and Boyce-Codd

What is Database ? Definition: A database functions as a virtual repository, housing, organizing, and effectively managing data. It serves as both a physical or digital storage structure that embodies a particular data model. The database represents the tangible realization of this design, where data is stored and administered. Serving as a central nexus for