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#helloconnection 50 interview SQL questions, including both technical and non-technical questions, along with their answers PART-3 21. What is the difference between SQL and PL/SQL?    - Answer: SQL is a standard language for accessing and manipulating databases, while PL/SQL (Procedural Language/SQL) is an extension of SQL used in Oracle databases that includes procedural programming constructs.    22. What is a composite key?    - Answer: A composite key is a primary key composed of two or more columns, used to identify a row uniquely.    23. What is a self-join?    - Answer: A self-join is a join in which a table is joined with itself, typically to compare rows within the same table.    24. What is a data warehouse?    - Answer: A data warehouse is a centralized repository of integrated data from one or more disparate sources, used for reporting and data analysis.    25. What is an OLAP cube?    - Answer: An OLAP (Online Analytical Processing) cube is a multi-dimensional array of data, used to perform complex queries and analysis on large datasets.    26. What is the difference between RANK() and DENSE_RANK()?    - Answer: Both functions assign ranks to rows within a partition of a result set. RANK() leaves gaps in the ranking sequence after duplicate values, while DENSE_RANK() does not.    27. What is the SQL CASE statement?    - Answer: The CASE statement is a conditional expression, similar to if-then-else statements in programming, which evaluates a list of conditions and returns one of multiple possible result expressions.    28. What is a recursive query?    - Answer: A recursive query is a query that refers to itself. It is commonly used to deal with hierarchical or tree-structured data.    29. What is a transaction in SQL?    - Answer: A transaction is a sequence of one or more SQL operations treated as a single logical unit of work. It ensures data integrity by adhering to ACID properties.    30. What is a correlated subquery?    - Answer: A correlated subquery is a subquery that uses values from the outer query. It is evaluated once for each row processed by the outer query. #sql #mysql #sqlquestion #sqljob

Getting 3rd Highest Salary in SQL: -------------------------------------- How many ways do you know, to get the 3rd highest salary in SQL? https://lnkd.in/dK3uu5Gt #sqlinterview #sql #techpoint #techpointfundamentals

SQL Lessons — CASE Statements. I just learned about CASE Statements in MySQL. The SQL CASE statement is a conditional expression that allows for the execution of different actions based on specified conditions. In this query below I used a CASE statement to show which managers of a company had either a pay raise of more than $30,000 or a pay raise equal to or less than $30,000 from an employee database. You can see a portion of the final output in the comment section of this post. #MySQL #SQL #SQLSkills #SQLTraining #DataAnalysis #DataAnalytics #DataAnalyst #BusinessAnalyst #BusinessAnalysis #Data

SQL - Between Operator https://lnkd.in/dxY8M5QV #sql #like #sqlfunction #function #Between #operator #inoperator The SQL BETWEEN Operator The BETWEEN operator selects values within a given range. The values can be numbers, text, or dates. The BETWEEN operator is inclusive: begin and end values are included. --Syntax SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2; --All The Value select * from EmployeeDetail -- Using Number Value in Between Operator select * from EmployeeDetail Where salary Between 10000 and 20000 --using Text Value in Between Operator select * from EmployeeDetail where first_name Between 'Den' and 'Karen' -- Using Date Value in Between Operator select * from EmployeeDetail where hire_date Between '2020-01-01' and '2023-01-01' NOT BETWEEN To display the products outside the range of the previous example, use NOT BETWEEN: -- Using Number Value in Between Operator select * from EmployeeDetail Where salary not Between 10000 and 20000 --using Text Value in Between Operator select * from EmployeeDetail where first_name not Between 'Den' and 'Karen' -- Using Date Value in Between Operator select * from EmployeeDetail where hire_date not Between '2020-01-01' and '2023-01-01' SQL (Structure Query Language) Playlist https://lnkd.in/eBs-Yk3R #Subscribe the Channel Link :- #bansodetechsolution #ajupgrading https://lnkd.in/gyegRMNs If any Queries or Doubts DM me on #instagram :- #bansode_ajay_2102 https://lnkd.in/gXJRZsis @AjUpgradingBANSODETECHSOLUTION LinkedIn Profile https://lnkd.in/ddFs-HGD Link for slides, code samples, and text version of the video #blogger https://lnkd.in/djWFt-dw #structurequerylanguage #sql

Getting 3rd Highest Salary in SQL: -------------------------------------- How many ways do you know, to get the 3rd highest salary in SQL? https://lnkd.in/dK3uu5Gt #sqlinterview #sql #techpoint #techpointfundamentals

🚀 SQL Challenge Q15 .The table named EMP has eight columns EMPNO NUMBER(4) NOT NULL: A column named EMPNO that can store up to 4-digit numbers. It cannot be empty. ENAME VARCHAR2(10): A column named ENAME that can store up to 10 characters for the employee's name. JOB VARCHAR2(9): A column named JOB that can store up to 9 characters for the employee's job title. MGR NUMBER(4): A column named MGR that can store up to 4-digit numbers for the manager's ID. HIREDATE DATE: A column named HIREDATE to store the date when the employee was hired. SAL NUMBER(7, 2): A column named SAL to store the employee's salary, with up to 7 digits in total, including 2 decimal places. COMM NUMBER(7, 2): A column named COMM to store the employee's commission, with up to 7 digits in total, including 2 decimal places. DEPTNO NUMBER(2): A column named DEPTNO that can store up to 2-digit numbers for the department number. PRIMARY KEY (EMPNO): This makes sure that each EMPNO value is unique and not empty, serving as the primary identifier for each row in the table. A.WRITE A QUERY TO DISPLAY EMPLOYEES WHO ARE EARNING 3TH HIGHEST SALARY FROM EACH JOB WISE BY USING DENSE_RANK() ALONG WITH INLINE VIEW? B.WRITE A QUERY DISPLAY THE 3RD SENIOR MOST EMPLOYEE DETAILS FROM EACH DEPTNO WISE BY USING DENSE_RANK() ALONG WITH INLINE VIEW? Difficulty Level : Medium #Oraclesql #SQL #sqlpractice #sqldatabase #mysql #sqlchallenge #sqldatabae

🔍 Discover the power of conditional logic in PostgreSQL with the CASE statement! Learn how to streamline your queries and perform dynamic data transformations. Check out this insightful guide: https://lnkd.in/d3MmA28h #PostgreSQL #SQL #DataAnalysis

📚 #SQL #Class #Day03 Welcome back, SQL enthusiasts! Today, we're diving deeper into the world of SQL with #SQL #Data #types and #Constraints SQL constraints are rules that enforce the integrity of data in a database. They define certain conditions that must be satisfied for data to be inserted, updated, or deleted in a table. #NOT NULL Constraint #UNIQUE Constraint ##PRIMARY KEY Constraint #FOREIGN KEY Constraint #CHECK Constraint #DEFAULT Constraint NOT NULL - Ensures that a column cannot have a NULL value UNIQUE - Ensures that all values in a column are different PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table FOREIGN KEY - Prevents actions that would destroy links between tables CHECK - Ensures that the values in a column satisfies a specific condition DEFAULT - Sets a default value for a column if no value is specified --- DATA TYPE in sql Server -- char(n): -- varchar(n): -- varchar(max): -- text: --nchar: nvarchar: --bit (Boolean): --tinyint: -- smallint: -- int: --- bigint:  -- decimal(p,s) Float: -- numeric(p,s): ---datetime:  ---date:  ---time:  --- datetimeoffset: --- binary(n): Fixed width binary string. Example:  binary(4) can store binary data. --- varbinary(max): Variable width binary string for large data.  Example: varbinary(max) can store image files. We explain each constraint type in detail, providing examples to illustrate their usage and importance in maintaining data consistency and integrity in SQL Server databases. Whether you're a beginner or an experienced SQL developer, understanding constraints is essential for effective database management. Join us to master SQL constraints and enhance your database skills today! . 📌 🎥 #Ready to see these commands in action? Check out our #Day03 #SQL tutorial video here for step-by-step demonstrations and practical examples! https://lnkd.in/gVHAHn_M 💡 Ready to Dive In? SQL Server offers a robust set of features and tools for managing your data effectively. Whether you're a seasoned database administrator or just getting started with SQL, mastering SQL Server can open up a world of possibilities for your data-driven projects. Ready to embark on your SQL journey? Join our group now and stay tuned for updates on class schedules and exclusive content. https://lnkd.in/gxZbngZA Follow for more. https://lnkd.in/e5aDpPUm Let's unlock the power of SQL together and elevate your data analysis game! 💡 #SQL #DataLovers #FreeLearning #learning #DataManagement #Database #SQL #Microsoft #DataInfrastructure #SQLServer Feel free to reach out if you have any questions or need assistance.

SQL Journey Day-3 Subqueries: Subqueries in SQL, also known as nested queries or inner queries, are SQL queries embedded within another SQL statement. They allow you to perform complex operations by nesting one query inside another. Common Use Cases: 1- Filtering Data: Subqueries can be used to filter rows based on a condition. For example, selecting employees whose salary is greater than the average salary. 2- Nested Aggregates: Subqueries can be used to calculate aggregates within aggregates. For example, finding the maximum salary among departments with more than five employees. 3- Correlated Subqueries: Subqueries can reference columns from the outer query, allowing for more complex filtering conditions. 4- Exists and Not Exists: Subqueries can be used with EXISTS and NOT EXISTS operators to check for the existence of rows in a correlated subquery. Zain Ul Hassan

Here is some interesting sql questions for 2+ year experience