{"id":28961465,"url":"https://github.com/debjyotisaha/learning-sql","last_synced_at":"2026-02-02T03:31:59.244Z","repository":{"id":290581889,"uuid":"974934885","full_name":"DebjyotiSaha/Learning-SQL","owner":"DebjyotiSaha","description":"This repository contains a comprehensive collection of SQL concepts, use cases, and practical examples designed to build strong foundational and advanced SQL skills.","archived":false,"fork":false,"pushed_at":"2025-05-19T21:21:27.000Z","size":343,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-06-24T02:03:35.624Z","etag":null,"topics":["sql"],"latest_commit_sha":null,"homepage":"","language":"TSQL","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/DebjyotiSaha.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2025-04-29T14:23:49.000Z","updated_at":"2025-05-19T21:21:30.000Z","dependencies_parsed_at":"2025-04-29T15:42:22.578Z","dependency_job_id":"2e68da23-05a0-4003-b525-9bc3250faa32","html_url":"https://github.com/DebjyotiSaha/Learning-SQL","commit_stats":null,"previous_names":["debjyotisaha/learning-sql"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/DebjyotiSaha/Learning-SQL","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/DebjyotiSaha%2FLearning-SQL","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/DebjyotiSaha%2FLearning-SQL/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/DebjyotiSaha%2FLearning-SQL/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/DebjyotiSaha%2FLearning-SQL/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/DebjyotiSaha","download_url":"https://codeload.github.com/DebjyotiSaha/Learning-SQL/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/DebjyotiSaha%2FLearning-SQL/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":29003227,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-02-02T01:32:03.847Z","status":"online","status_checked_at":"2026-02-02T02:00:07.448Z","response_time":58,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["sql"],"created_at":"2025-06-24T02:03:36.754Z","updated_at":"2026-02-02T03:31:58.544Z","avatar_url":"https://github.com/DebjyotiSaha.png","language":"TSQL","funding_links":[],"categories":[],"sub_categories":[],"readme":"# 🧠 SQL Mastery: From Basics to Advanced\n\nWelcome to the **SQL Mastery Repository**, a complete walkthrough of essential and advanced SQL concepts. This repo is built to help you **learn, practice, and master SQL** as used in real-world data engineering, analytics, and business environments.\n\n---\n\n## 📘 Overview\n\nSQL (Structured Query Language) is the standard language for managing and analyzing data in relational databases. In most organizations, SQL is at the heart of roles like:\n\n- 📊 Data Analysts\n- 🧮 Financial Analysts\n- 🛠️ Data Engineers\n- 🔍 Risk Managers\n- 🧠 Business Intelligence Developers\n\nThis repository guides you through how SQL is used across the data pipeline—from **querying** and **transforming data**, to **optimizing performance** and **building scalable data models**.\n\n---\n\n## 🔄 Real-World Data Flow\n\nA typical real-world SQL workflow looks like:\n\n1. Analysts write complex queries to extract insights.\n2. Engineers extract, transform, and load (ETL) data into warehouses.\n3. Stakeholders access data through dashboards and views.\n4. Performance, maintainability, and security are top concerns.\n\n---\n\n## 💡 Challenges in SQL Projects\n\n- Code Redundancy\n- Performance Bottlenecks\n- Query Complexity\n- Maintenance Difficulty\n- Database Stress\n- Security Concerns\n\n---\n\n## ✅ Smart SQL Techniques Covered\n\n| Technique     | Purpose                                                   |\n|--------------|------------------------------------------------------------|\n| Subqueries    | Break complex queries into manageable logic blocks         |\n| CTEs          | Improve readability and reuse of logic                     |\n| Views         | Create virtual tables for abstraction and security         |\n| Temp Tables   | Store intermediate results temporarily                     |\n| CTAS          | Create physical tables from SQL queries for performance    |\n| Stored Procedures | Encapsulate logic with parameters and error handling |\n\n---\n\n## 🔍 Topics Breakdown\n\n### 1. 🧩 Subqueries\n- Scalar, Row, Table subqueries\n- Subqueries in `SELECT`, `FROM`, `WHERE`, `JOIN`\n- Use of `IN`, `EXISTS`, `ANY`, `ALL`\n\n### 2. 🔗 CTEs (Common Table Expressions)\n- Standalone, Nested, Multiple CTEs\n- Recursive CTEs (e.g., sequences, hierarchy)\n- Improves modularity and readability\n\n### 3. 🪞 Views\n- Virtual tables without storing data\n- Useful for security and abstraction\n- Ideal for BI tools and data access layers\n\n### 4. 💽 CTAS (Create Table As Select)\n- Create snapshot tables\n- Optimizing large queries\n- Useful for ETL and data mart creation\n\n### 5. ⏳ Temp Tables\n- Store intermediate results\n- Used in multi-step transformations\n- Cleared automatically after session/query\n\n### 6. ⚙️ Stored Procedures\n- Reusable scripts for automation\n- Parameters, variables, and control flow\n- Error handling with `TRY...CATCH`\n- Encapsulates business logic securely\n\n---\n\n## 🧾 SQL Object Comparison Matrix\n\n| Feature         | Subquery | CTE     | Temp Table | CTAS    | View    |\n|----------------|----------|---------|------------|---------|---------|\n| **Storage**     | Memory   | Memory  | Disk       | Disk    | Virtual |\n| **Lifetime**    | Temporary| Temporary | Session  | Permanent| Permanent |\n| **Scope**       | One Query| One Query| Multiple Queries | Multiple | Multiple |\n| **Reusability** | Low      | Medium  | Medium     | High    | High    |\n| **Up-to-Date**  | Yes      | Yes     | No         | No      | Yes     |\n\n---\n\n## 🧠 Use Cases Across Roles\n\n- Business Analysts: Insightful views \u0026 summaries\n- Data Engineers: ETL pipelines using CTEs \u0026 CTAS\n- Analysts: Ad-hoc reporting with subqueries\n- DBAs: Manage access \u0026 optimize queries using Views \u0026 Procedures\n\n---\n\n## 🛠️ Sample Scenarios\n\n- Segment customers by sales\n- Generate monthly order trends\n- Update and clean null values\n- Create performance-optimized data marts\n- Run business-specific parameterized reports\n\n---\n\n## 🚀 Getting Started\n\n1. Clone the repo:\n   ```bash\n   git clone https://github.com/your-username/sql-journey.git\n   cd sql-journey\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdebjyotisaha%2Flearning-sql","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdebjyotisaha%2Flearning-sql","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdebjyotisaha%2Flearning-sql/lists"}