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14+ SQL beginner interview Q&As

SQL interview Questions & Answers is a must for any developer as all non-trivial applications need to talk to a database with CRUD operations. Q3 – Q15 are very popular…

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15+ SQL optimisation interview questions & answers with scenarios

1) Select fields instead of using SELECT *. The “*” is used as a short hand to query all available data from a table. If a table has many fields…

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15+ SQL scenarios based interview Q&As – part 1

15+ SQL interview questions and answers to solve real business scenarios. SQL is widely used in building microservices & Big Data projects. Learning SQL syntax is easy, but being able to convert a given business requirement into a query takes lots of practice. These scenarios based interview questions can assesses your experience.…

15+ SQL scenarios based interview Q&As – Part 2

This extends Q01 – Q03 at 15+ SQL scenarios based interview questions answered. Q04 When you have a table that maintains history of record updates, how will you go about…

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15+ SQL scenarios based interview Q&As – Part 3

This extends 15+ SQL scenarios based interview Q&As – Part 2. Q07 In What order the SELECT SQL statements are executed? A07 Here is the the order in which the…

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18 SQL best practices interview Q&As

It pays to understand the order of operations in SQL. This is demonstrated with an example below in #5, which is an absolute must know. Have this order of execution visibly pinned or memorised.

Let’s start with the best practices.

#1. Use uppercase for the keywords like SELECT, FROM, JOIN, GROUP BY, WHERE, etc.…

Common Table Expressions (i.e. CTE) in SQL using the “WITH” clause

Common Table Expressions or CTE’s for short are used in SQL to simplify complex joins and subqueries, and to provide a means to query hierarchical data such as an organisational…

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SQL analytic functions interview questions – Part 1

Data Engineers & analysts must know the analytic functions applied over a window of rows is a powerful tool to analyse the data. This post compliments “Apache Spark window functions” by focusing on MySQL server. You can also apply this on Big Data SQL engines like Hive & impala, but the syntax can be slightly different, but the idea is the same.…

SQL analytic functions interview questions – Part 2

This extends SQL window function for analytical queries interview questions – Part 1 Analytic function construct


analytic_function_name([argument_list])
OVER (
[PARTITION BY partition_expression,…]
[ORDER BY sort_expression, … [ASC|DESC]])

analytic_function_name([argument_list])

OVER (

[PARTITION BY partition_expression,…]

[ORDER BY sort_expression, … [ASC|DESC]])

The analytic function names can be RANK(), DENSE_RANK(), ROW_NUMBER(), MIN(column), MAX(column), SUM(column), COUNT(),…

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SQL analytic functions interview questions – Part 3

This extends SQL analytic functions interview questions – Part 2 and SQL analytic functions interview questions – Part 1. The below example was created in IMPALA SQL engine with Common…

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Blog Archives

14+ SQL beginner interview Q&As

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15+ SQL optimisation interview questions & answers with scenarios

Members Only Content

15+ SQL scenarios based interview Q&As – part 1

15+ SQL scenarios based interview Q&As – Part 2

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15+ SQL scenarios based interview Q&As – Part 3

Members Only Content

18 SQL best practices interview Q&As

Common Table Expressions (i.e. CTE) in SQL using the “WITH” clause

Members Only Content

SQL analytic functions interview questions – Part 1

SQL analytic functions interview questions – Part 2

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SQL analytic functions interview questions – Part 3

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