/Sql-and-MySql-CheatSheet

SQL and MySql CheatSheet with Examples for Interviews Preparation as well as Developers

Sql-and-MySql CheatSheet with Examples for Interview Preparation as well as Developers

Top 10 SQL Concepts for Job Interview

  1. SELECT and FROM: This is the “heart” of any SQL query - SELECT columns FROM table.

  2. WHERE: This acts as a filter and allows you to select only relevant rows based on conditions.

  3. GROUP BY: This helps you aggregate the data by grouping columns.

  4. AVG/SUM/MAX/MIN: These are aggregate functions that help you summarise the data.

  5. COUNT and DISTINCT: Count helps you find the number of entries and Distinct helps you find unique entries.

  6. CASE WHEN: This is a very useful way to create a new derived field or perform complex aggregate operations.

  7. JOIN: Join helps you combine data from different tables using join conditions. Please get familiar with inner and left/right/full outer joins.

  8. UNION: Union and Union All help you to combine data from multiple tables with similar structure.

  9. WINDOW FUNCTION: Allow you to perform calculations across a set of rows.

  10. CTE and SUBQUERY: They help you create more complex queries by combining smaller queries.