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Jul 5, 2024 · Explore the Top 70+ SQL Interview Questions for beginners and experienced professionals. Master fundamental concepts, complex queries, database design, indexing, and performance tuning to ace your SQL interviews with top companies.
- Top 45+ SQL Query Interview Questions and Answers (2024)
Prepare for your SQL query interviews with confidence!...
- Top 45+ SQL Query Interview Questions and Answers (2024)
- SQL Interview Questions For Freshers
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1. What is DBMS?
A Database Management System (DBMS) is a program that controls creation, maintenance and use of a database. DBMS can be termed as File Manager that manages data in a database rather than saving it in file systems. 👉 Free PDF Download: SQL Interview Questions & Answers >>
2. What is RDBMS?
RDBMS stands for Relational Database Management System. RDBMS store the data into the collection of tables, which is related by common fields between the columns of the table. It also provides relational operators to manipulate the data stored into the tables. Example: SQL Server.
3. What is SQL?
SQL stands for Structured Query Language , and it is used to communicate with the Database. This is a standard language used to perform tasks such as retrieval, updation, insertion and deletion of data from a database. Standard SQL Commandsare Select.
11. What is normalization?
Normalization is the process of minimizing redundancy and dependency by organizing fields and table of a database. The main aim of Normalization is to add, delete or modify field that can be made in a single table.
12. What is Denormalization?
DeNormalization is a technique used to access the data from higher to lower normal forms of database. It is also process of introducing redundancy into a table by incorporating data from the related tables.
13. What are all the different normalizations?
Database Normalizationcan be easily understood with the help of a case study. The normal forms can be divided into 6 forms, and they are explained below -. 1. First Normal Form (1NF):. This should remove all the duplicate columns from the table. Creation of tables for the related data and identification of unique columns. 1. Second Normal Form (2NF):. Meeting all requirements of the first normal form. Placing the subsets of data in separate tables and Creation of relationships between the tab...
21. What are the types of subquery?
There are two types of subquery – Correlated and Non-Correlated. A correlated subquery cannot be considered as independent query, but it can refer the column in a table listed in the FROM the list of the main query. A Non-Correlated sub query can be considered as independent query and the output of subquery are substituted in the main query.
22. What is a stored procedure?
Stored Procedure is a function consists of many SQL statement to access the database system. Several SQL statements are consolidated into a stored procedure and execute them whenever and wherever required.
23. What is a trigger?
A DB trigger is a code or programs that automatically execute with response to some event on a table or view in a database. Mainly, trigger helps to maintain the integrity of the database. Example: When a new student is added to the student database, new records should be created in the related tables like Exam, Score and Attendance tables.
41. What is Union, minus and Interact commands?
UNION operator is used to combine the results of two tables, and it eliminates duplicate rows from the tables. MINUS operator is used to return rows from the first query but not from the second query. Matching records of first and second query and other rows from the first query will be displayed as a result set. INTERSECT operator is used to return rows returned by both the queries.
42. What is an ALIAS command?
ALIAS name can be given to a table or column. This alias name can be referred in WHERE clauseto identify the table or column. Example-. Here, st refers to alias name for student table and Ex refers to alias name for exam table.
43. What is the difference between TRUNCATE and DROP statements?
TRUNCATE removes all the rows from the table, and it cannot be rolled back. DROP command removes a table from the database and operation cannot be rolled back.
Prepare for your SQL interview with 50 questions and answers for freshers and experienced candidates. Learn about DBMS, RDBMS, SQL, database, tables, keys, joins, normalization, indexes, cursors and more.
Feb 15, 2024 · Learn common SQL interview questions and answers for job hunters and hiring managers, covering general topics and technical skills. Find out what SQL is, its applications, commands, functions, queries, and more.
- Write a SQL query to fetch “FIRST_NAME” from the Student table in upper case and use ALIAS name as STUDENT_NAME. SELECT upper(FIRST_NAME) as STUDENT_NAME from Student;
- Write a SQL query to fetch unique values of MAJOR Subjects from Student table. SELECT DISTINCT MAJOR from STUDENT; or SELECT MAJOR FROM STUDENT GROUP BY(MAJOR);
- Write a SQL query to print the first 3 characters of FIRST_NAME from Student table. SELECT SUBSTRING(FIRST_NAME, 1, 3) FROM Student;
- Write a SQL query to find the position of alphabet (‘a’) int the first name column ‘Shivansh’ from Student table. SELECT INSTR(FIRST_NAME, 'a') FROM Student WHERE FIRST_NAME = 'Shivansh';
Summary. Basic to intermediate SQL topics. 50 essential SQL questions. Best for 1 month of prep time. Award. SQL 50. Complete the study plan to win the badge! View More. Copyright © 2024 LeetCode. Crack SQL Interview in 50 Qs.
May 29, 2024 · Explore 50+ Specific SQL Topic Interview Questions. JOINs. GROUP BY. Data Analysis in SQL. Window Functions. Common Table Expressions. Advanced SQL. Good Luck with Your Interview! Are you gearing up for a SQL interview?
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Jan 3, 2024 · 1. What is Pattern Matching in SQL? SQL pattern matching provides for pattern search in data if you have no clue as to what that word should be.
