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Master SQL, PostgreSQL, MySQL, MongoDB, and trending open-source databases. Learn optimization, design patterns, and best practices for modern data management.

323 articles
1 min read

SQL INSERT

The INSERT statement is used to add new records into a table. 🔹 Basic Syntax 🔹 Insert Multiple Rows (MySQL, PostgreSQL, SQL Server) 🔹…

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SQL LIMIT / TOP / FETCH FIRST

These keywords let you limit how many rows your query returns. Usage differs slightly by database. 🔹 Syntax by DBMS 🔹 Pagination Example (MySQL/PostgreSQL)…

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SQL ORDER BY

The ORDER BY clause lets you sort the rows returned by a query — either in ascending or descending order. 🔹 Basic Usage 🔹…

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SQL LIKE & Wildcards

The LIKE operator is used to search for patterns in text. It works with wildcards to match partial strings. 🔹 Wildcards You Can Use…

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SQL Comparison Operators

Comparison operators help you compare values in the WHERE clause to filter data. 🔹 Common Comparison Operators Operator Meaning Example = Equal to WHERE…

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SQL AND / OR / NOT

Use AND, OR, and NOT to build complex filters in your WHERE clause. 🔹 How They Work 🔹 Examples 🧠 Quick Recap Operator Meaning…

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SQL WHERE

The WHERE clause lets you filter rows based on conditions, so you get only the data you want. 🔹 Basic Syntax This returns employees…

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SQL SELECT DISTINCT

Sometimes, your query results have duplicates. To get only unique (different) values, we use DISTINCT. 🔹 How to Use DISTINCT 🧠 What DISTINCT Does…

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SQL SELECT

The SELECT statement is how we read data from a table. Let’s quickly go through the different ways to use it. 🔹 Basic Usage…

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SQL Data Types

SQL Data Types (Oracle, MySQL, PostgreSQL, SQL Server) Choosing the right data type for each column is key to ensuring data integrity, optimizing storage,…

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SQL Comments

Comments are notes or explanations you add inside your SQL code to make it easier to understand — both for yourself and others reading…

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SQL Statements

SQL statements are the individual commands you use to interact with the database. Each statement tells the database what action to perform — from…