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10: Getting started with MySQL database beginner tutorial

All Java developers not only must know “SQL”, but also a database is required for “JDBC tutorials”, “Hibernate Tutorials”, and so on. Any decent Java application will require a database. So, your self-taught Java projects must perform CRUD (i.e. Create Read, Update and Delete) operations on the database.

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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 with the interviewers. If you want to quickly practice your SQL skills try DB Fiddle or install MySQL locally as...

15 Database design interview Q&As

Q1. What is normalization? When to denormalize? A1. Normalization is a design technique that is widely used as a guide in designing relational databases. Normalization is essentially a two step process that puts data into tabular form by removing repeating groups and then removes duplicated data from the relational tables....

15+ SQL scenarios based interview questions answered

Q1 How will you go about identifying duplicate records in a table?
A1 The following SQL query will do the trick.

Note: Interviewer is testing if you understand that the aggregate queries need to have a “GROUP BY

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Auditing database record changes in Oracle

Q. What are some of the considerations in auditing database table data? A. Creating audit tables without any constraints to store record changes.  Audit tables are heavily hit with inserts, hence needs to have fewer indices if at all required. … Read more ›...

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 chart. This was also introduced in MySQL 8 – Using … Read more ›...

Deleting records in SQL Interview Questions and Answers

The following is a very popular SQL job interview question. Q. What is the difference between “Truncate” and “Delete” commands? A.  TRUNCATE TABLE_NAME always locks the table and page but not each row, … Read more ›...

SQL querying Temporal tables & SCD Type 2

Q1. What is a temporal table? A1. Temporal tables store and maintain information with respect to time. This tracks data changes, and enables us to maintain and manage the history of the data in a table. … Read more ›...

SQL retrieving the latest records interview Q&As

This question can reveal a lot about your ability to write SQL queries as different approaches can be used and there will be drill down on pros and cons of each approach. Q1. Given the following SQL, how do you retrieve the latest records by updated date for each user?...

SQL Subquery interview questions and answers

Q. What is a subquery?
A. Subquery or Inner query or Nested query is a query in a query. A subquery is usually added in the WHERE clause of the sql statement. A subquery can be nested inside a SELECT, INSERT,

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SQL window function for analytics interview questions answered

Data Engineers & analysts must know the Window functions as it is a powerful tool to analyse the data. This post compliments “Apache Spark window functions” focus on using SQL on MySQL server covered. You can also apply this on Big Data SQL engines like Hive &

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Transaction management in SQL — Sybase example

Q. How do you perform transaction management in SQL stored procedures?
A. Handled with begin, commit, and rollback ‘tran’ commands in Sybase server.

Q. Why is it important?

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800+ Java Q&As & tutorials