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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

9 Top AWS Services a Quick List

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In this post, I have explained the top AWS services list . These services are useful to read before your next interview. knowing this list is a must for all cloud-computing engineers. AWS provides various services. This post gives a clear understanding of AWS's top services.  AWS Books AWS in action AWS Cookbook Not only for traditional services, but it also offers services for Mobile IoS and Android Os.  Aws Service catalog  helps organizations to manage their IT services. AWS List of Top AWS Services Quick List These 9 Services of AWS are popular. I have explained each service to understand quickly. EC2 Lambda S3 DynamoDB IAM Amazon Cognito Device Farm Mobile analytics SNS 1. AWS EC2 Instance EC2: Amazon Elastic Compute Cloud (EC2) provides secure, scalable, on-demand hardware virtualization in the cloud. Using Amazon EC2 eliminates the need to invest in server hardware upfront so that users can focus on, develop, and deploy applications faster.  EC2 instances com

Top Data Science Tools Complete List

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Top data science tools and platform providers across the world. Useful information for data science and data analytics developers. 8 Top Data Analytics Tools List. Data Science is a combination of multiple skills. AI and Machine Learning are part of data science. You can create AI and Machine Learning products with data. Related Posts Top Skills You Need for Data Science Career Data Science Sample Project an Example

SQL PLSQL Top Reserved Keywords

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To become perfect in PL/SQL is an art. Knowing of top reserved words helps you to be a master in SQL. Before you start knowing reserved words, wait one moment. The reserved words are similar to the words that you use in normal SQL. SQL, PLSQL Reserved Words PL/SQL Reserved Words A Video on Basic PL/SQL Basic PL/SQL Video Lesson for all professionals. Related Posts 32 Complex SQL Queries popular e-book Introduction to SQL and PLSQL by Ruchin Jain

SQL Tester Ideas DATE, Numeric, CHAR, NULL

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I have shared top SQL Date functions along with Numeric, CHAR and NULL functions. List of Built-in Functions DATE-TIME functions Numeric functions Char functions Null-related functions 1. DATE/TIME functions SELECT p_code, launch_dt, CURRENT_DATE FROM product; CURRENT_DATE returns the CURRENT date. SELECT p_code, To_char(launch_dt, 'DD MONTH YYYY') reformatted_dt FROM product; TO_CHAR FUNCTION returns date IN char format. 2. Numeric functions SELECT p_code, price, (price - 20), Abs(price - 20.00) FROM product; ABS - FUNCTION returns the absolute value SELECT p_code, price, Round (price, 1) FROM product; ROUND FUNCTION - round TO 1 digit. SELECT p_code, price, Sign(price - 15) FROM product; SIGN FUNCTION - it returns the sign SELECT p_code, price, Trunc(price, 1) FROM product; TRUNC FUNCTION - truncates TO a certain number OF decimal places. 3. CHAR functions SELE

4 Built-in functions in SQL Explained Superbly

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Here're four types of built-in functions in SQL. You don't need to create these functions, and these come with your SQL. I am discussing today the  SQL functions List . SQL functions DATE-TIME functions Numeric functions Char functions Null-related functions 1. DATE-TIME functions   These are useful to get DATE and Time. Also, you can covert the DATE and TIME to Char. These are TO_CHAR, CURRENT_DATE, and CURRENT_TIME. 2. Numeric Functions   These functions you can use for numeric calculations. Those are TRUNC, SIGN, ROUND, ABS. 3. Char Functions   To handle string-related tasks you can use CHAR functions. The CHAR functions are like SUBSTR, CONCAT, LENGTH. 4. NULL related functions   To handle null values you can use different functions. Those are COALESCE, NVL, NULLIF This post covered all your answers for the SQL functions list, SQL built-in functions in Oracle, and SQL functions in any DBMS. Also, Read SQL tips to improve Query performance Summar

vi Editor Top Commands for Ubuntu OS

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I have given VI editor commands to use in Ubuntu operating system. You can practice using them for your benefit and you can complete your work quickly. To begin changing or adding to text with vi, you can enter Insert or Replace modes, as shown in the following list. When you enter Insert or Replace mode, the characters you type will appear in the text document (as opposed to being interpreted as commands).  vi filename This is the first command to enter into editor mode. Once you enter into editor mode, you need to enter other commands to complete your editing work. Press the Esc key t o exit to Normal mode after you are done inserting or replacing text. List of VI Editor Commands.. i—Typed text appears before current character. a—Typed text appears after current character. o—Open a new line below current line to begin typing. s—Erase current character and replace with new text. c?—Replace ? with l, w, $, or c to change the current letter, word, end of line, or line. r—Repla

Data science: Simple Project to Practice

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I want to share with you how to use Python for your Data science or analytics Projects. Many programmers struggle to learn Data science because they do not know where to start. You can get hands-on if you start with a mini-project. I have used Ubuntu Operating System for this project. You Need dual skills; Learning and Apply knowledge to become a data scientist. In Data science you need to learn and apply your knowledge.   After engineering, you can go for M Tech Degree.  You can become a real engineer if you apply engineering principles. So Data science also the same. Data Visualization in Python is my simple project Importance of Data Data is a precious resource in resolving Machine Learning and Data Science Problems.  Define first what is your problem. Collect Data  Wrangle the Data and Clean it. Visualize the Patterns In the olden days , you might be studied a subject called Statistical Analysis.  In this subject, you need to study the actual problem and collect the data in

6 Top Solidity Interview Questions

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Solidity is the prime language to write the logic for smart contracts in the Ethereum blockchain. These are selected interview questions refresh before you take an interview. Solidity Interview Questions on Solidity 1. What is Solidity? A) Solidity is the main language that you can use to write programs in Blockchain, such as smart contracts. 2. Where the Solidity programs run in Ethereum? A). Those will run in EVM. You can also call it an Ethereum Virtual Machine. 3. What kind of logic a Smart Contract can contain? A contract in the sense of Solidity is a collection of code (its functions) and data (its state) that resides at a specific address on the Ethereum blockchain 4). Can the source code of smart contracts accessible to the outside world?  A). No, it is not possible to access the source code to the network. Also, there is limited access to one smart contract logic to the other smart contract logic. Eve, file systems, and other processes cannot access the source