10+ GMR Hospitality and Retail Interview Questions and Answers

To delete records in a table, use the DELETE statement with the WHERE clause to specify the condition for deletion.

• Use the DELETE statement followed by the table name

• Add the WHERE clause to specify the condition for deletion

• Execute the query to delete the records

A primary key is a unique identifier for a record in a database table.

• A primary key must be unique and not null.

• It ensures the uniqueness and integrity of data in a table.

• Primary keys are used to establish relationships between tables.

• Examples of primary keys include social security numbers, email addresses, or auto-incremented IDs.

Code to generate Fibonacci series

• Start with 0 and 1 as the first two numbers

• Add the previous two numbers to get the next number in the series

• Repeat until desired number of terms is reached

A unique key is a column or a set of columns in a database table that uniquely identifies each row.

• A unique key ensures that no two rows in a table have the same values for the specified column(s).

• It is used to enforce data integrity and prevent duplicate entries.

• A table can have multiple unique keys, but each unique key can only have one row with a specific set of values.

• Unique keys can be used as a reference for relationships between tables.

Types of joins include inner join, outer join (left, right, full), cross join, self join.

• Inner join: returns rows when there is a match in both tables

• Outer join: returns all rows from one table and matching rows from the other table

• Cross join: returns the Cartesian product of the two tables

• Self join: joins a table to itself

A type of joint where two or more tables are combined based on a related column between them.

• Types include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• Used in SQL queries to retrieve data from multiple tables.

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id;

WHERE clause in SQL is used to filter records based on specified conditions.

• WHERE clause is used in SELECT, UPDATE, and DELETE statements to filter records.

• It follows the FROM clause in a SQL statement.

• Conditions in WHERE clause can include comparison operators like =, <>, <, >, etc.

• Logical operators such as AND, OR, and NOT can be used to combine multiple conditions.

• Example: SELECT * FROM employees WHERE department = 'IT';

Progressive testing is a software testing approach where testing is done incrementally as new features are added.

• Testing is done in stages as new features are developed

• Each stage builds upon the previous one

• Helps in identifying issues early in the development process

SQL Server is a relational database management system developed by Microsoft.

• Developed by Microsoft

• Used for managing relational databases

• Supports T-SQL (Transact-SQL) language

• Provides tools for data storage, retrieval, and manipulation

Join is a SQL operation used to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

A project in SQL developer involves designing, implementing, and maintaining databases for various applications.

• Understand project requirements and design database schema accordingly

• Write efficient SQL queries to retrieve and manipulate data

• Optimize database performance by indexing, normalization, and query tuning

• Collaborate with developers and stakeholders to ensure database meets project needs

Types of SQL include DDL, DML, DCL, and TCL.

• DDL (Data Definition Language) - used to define the structure of database objects (CREATE, ALTER, DROP)

• DML (Data Manipulation Language) - used to manipulate data in database objects (SELECT, INSERT, UPDATE, DELETE)

• DCL (Data Control Language) - used to control access to data (GRANT, REVOKE)

• TCL (Transaction Control Language) - used to manage transactions (COMMIT, ROLLBACK)

Normalization in SQL is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a database into smaller, more manageable tables.

• It helps in reducing data redundancy by storing data in a structured way.

• Normalization ensures data integrity by minimizing the chances of inconsistencies.

• There are different normal forms like 1NF, 2NF, 3NF, etc. to guide the normalization process.