Data analytics guides: SQL, Python, BI tools and careers

These data analytics guides run from SQL joins and window functions to data cleaning, A/B testing, Python libraries, BI dashboards and the data analyst and data engineer roadmaps. Each guide uses worked examples and states which tools and versions it checked.

Last updated: 11 November 2026.

How do you learn SQL for analytics?

SQL joins explained with examples: inner, left, right and full: SQL joins explained with examples: inner, left, right and full joins return 3, 4, 4 and 5 rows on two small tables, plus a MySQL FULL JOIN substitute.
SQL window functions explained: ROW_NUMBER, RANK, LAG, running totals: SQL window functions explained with result tables: ROW_NUMBER, RANK and DENSE_RANK on a 45-unit tie, LAG, LEAD, running totals and the default frame trap.
SQL interview questions and answers for 2027: from basics to joins: SQL interview questions and answers: 20 questions on joins, aggregation, CTEs and window functions, each run on SQLite 3.54.0 with the real output shown.

How do you clean, test and analyse data?

Data cleaning techniques in Excel, SQL and Python: Data cleaning techniques in Excel, SQL and Python: a seven-step order, one messy 6-row table cleaned two ways, and when not to delete values or outliers.
A/B testing explained: how analysts and product teams run experiments: A/B testing explained for analysts: the six steps, a sample size of 3,839 visitors per variant for a 10% to 12% lift, p-values, and the peeking trap.
Best Python libraries for data analysis in 2027: pandas to DuckDB: Python libraries for data analysis as of 11 November 2026: pandas 3.1.1, Polars 2.1.0, DuckDB 2.0.0 and seven more, with install lines and tested code.
Top 10 AI tools for data analysts in 2027 and what to verify: Ten AI tools for data analysts to know going into 2027, across spreadsheets, SQL, notebooks and BI, with what each does and the check an analyst owns.

Which BI, pipeline and database tools matter?

Best BI and dashboard tools in 2027: Power BI, Tableau, free ones: Best BI tools as of 11 November 2026: Power BI, Tableau, Data Studio (formerly Looker Studio), Metabase and six more, with free routes and one limit each.
What is ETL? Data pipelines explained for beginners: What is ETL? Extract, transform, load explained with a 5-row pipeline run in Python, ETL vs ELT, batch vs streaming and the tools in the category.
MongoDB vs MySQL: differences, use cases and how to choose: MongoDB vs MySQL compared on data model, schema, joins, transactions and scaling, with 3 orders modelled both ways and a decision guide by use case.

What are the data career paths?

Data analyst roadmap for 2027: skills, tools and projects in order: Data analyst roadmap for 2027 in seven stages: Excel and statistics, SQL, BI, Python, storytelling, domain and portfolio, each with a project and a proof.
Data engineer roadmap for 2027: SQL, pipelines and the cloud: A data engineer roadmap for 2027 in nine stages, from SQL and Python to Airflow, dbt and Kafka, with a DuckDB pipeline tested on Python 3.12.

Certification Program in Data Analytics with AI and Gen AI, E&ICT Academy IIT Roorkee: Online programme from E&ICT Academy, IIT Roorkee: SQL, Python, Google Sheets, prompt engineering, LLM tools and agentic workflows, with a capstone project.
Analytics in the Age of AI, Vishlesan i-Hub IIT Patna: Live online programme from Vishlesan i-Hub, IIT Patna: SQL, Python, BI tools, applied machine learning and agentic analytics through hands-on projects.
Certification Program in Business Analytics with Gen and Agentic AI, BITSoM: Online certification from BITS School of Management: business analytics, SQL and Python, Tableau and Power BI, machine learning and building AI agents.
Executive Certificate Programme in Business Analytics and AI, IIM Ranchi: Online programme from IIM Ranchi: data management with SQL and Python, visualisation and storytelling, managerial statistics and machine learning for business.

Frequently asked questions

What should a data analyst learn first?

SQL comes first, because most analyst work starts with querying tables. The SQL joins and window functions guides use runnable examples, and the data analyst roadmap places SQL, spreadsheets, Python and a BI tool in a sensible order.

Which Python library is best for data analysis?

It depends on data size and skill. The Python libraries guide compares pandas, Polars and DuckDB with the same question answered in each, and notes version and Python-support details so readers can choose with evidence.

What is the difference between a data analyst and a data engineer?

A data analyst answers business questions from data, while a data engineer builds the pipelines and storage that deliver it. The data engineer roadmap and the ETL guide explain the tools and stages of the engineering side.