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Ace-Your-SQL-Interview

SQL interview questions assess a candidateu2019s understanding of database concepts, query writing, and problem-solving with relational data.

SagarHeddurshetty
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Ace-Your-SQL-Interview

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  1. Ace Your SQL Interview Welcome, freshers! This presentation will equip you with the knowledge and strategies to confidently tackle common SQL interview questions and stand out from the crowd.

  2. Agenda 1 Understanding SQL Basics Reviewing fundamental concepts every interviewer expects you to know. 2 Commonly Failed Questions Deep dive into tricky questions and how to approach them. 3 Practical Application & Tips Best practices and additional resources for interview success.

  3. SQL Basics: Keys and Constraints Primary Key Foreign Key A column (or set of columns) that uniquely identifies each row in a table. It cannot contain NULL values and must be unique. A column (or set of columns) in one table that refers to the primary key in another table. It establishes a link between two tables. Ensures data integrity. Maintains referential integrity. Only one primary key per table. Can contain duplicate and NULL values. Example: StudentID in a Students table. Example: StudentID in an Enrollments table, referencing StudentID in Students.

  4. SQL Basics: Joins Understanding different types of JOIN clauses is crucial for combining data from multiple tables. INNER JOIN Returns rows when there is a match in both tables. LEFT JOIN Returns all rows from the left table, and matching rows from the right table. NULL where no match. RIGHT JOIN Returns all rows from the right table, and matching rows from the left table. NULL where no match. FULL OUTER JOIN Returns rows when there is a match in one of the tables. Returns NULL when no match.

  5. Commonly Failed: DELETE vs TRUNCATE vs DROP DELETE Removes rows from a table based on a WHERE clause. It's a DML command. Can be rolled back. Fires triggers. Slower for large tables. TRUNCATE Removes all rows from a table, but keeps the table structure. It's a DDL command. Cannot be rolled back. Does not fire triggers. Faster for large tables. DROP Removes an entire table from the database, including its structure and data. It's a DDL command. Cannot be rolled back. All associated objects (indexes, constraints) are also removed. Always be cautious when using TRUNCATE and DROP as their actions are irreversible.

  6. Practical Application & Tips Practice SQL Queries: Solve problems on platforms like LeetCode or HackerRank. Understand Execution Plan: Know how SQL queries are optimized for performance. Whiteboard Practice: Be ready to write SQL queries by hand or on a whiteboard. Ask Clarifying Questions: Don't hesitate to ask for more details on a problem. Explain Your Thought Process: Interviewers want to understand how you approach problems.

  7. Connect With Us! Ready to boost your SQL skills and land your dream job? 7498992609 9503397273 Call or message us Call or message us Or send us an email: enquiry@fusion-institute.com

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