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SQL Interview Success: Unlocking the Top 5 Frequently Asked Queries

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 Here are the five top commonly asked SQL queries in the interviews. These you can expect in Data Analyst, or, Data Engineer interviews. Top SQL Queries for Interviews 01. Joins The commonly asked question pertains to providing two tables, determining the number of rows that will return on various join types, and the resultant. Table1 -------- id ---- 1 1 2 3 Table2 -------- id ---- 1 3 1 NULL Output ------- Inner join --------------- 5 rows will return The result will be: =============== 1  1 1   1 1   1 1    1 3    3 02. Substring and Concat Here, we need to write an SQL query to make the upper case of the first letter and the small case of the remaining letter. Table1 ------ ename ===== raJu venKat kRIshna Solution: ========== SELECT CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS capitalized_name FROM Table1; 03. Case statement SQL Query ========= SELECT Code1, Code2,      CASE         WHEN Code1 = 'A' AND Code2 = 'AA' THEN "A" | "A
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4 Top Python Oops Concepts Simplify Your Coding

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Oops concepts in Python explained in this post. Python supports Encapsulation, Inheritance, Abstraction, Polymorphism and Dynamic binding. These simplify your coding effort. I have given examples on Python Oops ( Object oriented) concepts.

python oops concepts

Python Oops (Object oriented) Concepts

  1. Encapsulation
  2. Data hiding and abstraction
  3. Inheritance
  4. Polymorphism (overloading/overriding)
The fifth Python special property is Dynamic binding.

#1 Python Oops Encapsulation

Wrapping of data and functions in a single unit is called Encapsulation.

Encapsulation

#2 Python Oops Data Hiding and abstraction

User program refers to methods from an object is called abstraction. Keeping all the methods under one object called data hiding.

Abstraction

#3 Python Oops Inheritance

Inhering properties means, referring property of an object of a class from an Object of the other Class.

Inheritance

#4 Python Oops Polymorphism

Poly means many. The definition of one function can use for many. 

The best example is the "+" operator. You can use it for the addition of numbers, and concatenate of String. 

Polymorphism

#5 Dynamic Binding

Dynamically you can call one procedure during the execution of the main program is called Dynamic binding. 

Dynamic Binding

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