10+ Ditto Interview Questions and Answers

I have extensive experience in SQL database development and programming languages.

• I have worked with SQL databases such as MySQL, Oracle, and SQL Server.

• I am proficient in writing complex SQL queries, stored procedures, and triggers.

• I have experience in database design, normalization, and performance optimization.

• I am familiar with programming languages like Java, Python, and C#.

• I have developed applications that interact with databases using JDBC, SQLAlchemy, and ADO.NET.

A database is a structured collection of data that is stored and accessed electronically.

• DBMS stands for Database Management System, which is a software that manages databases.

• RDBMS stands for Relational Database Management System, which organizes data into tables with rows and columns.

• Examples of RDBMS include MySQL, Oracle, and SQL Server.

An index is a data structure that improves the speed of data retrieval operations on a database table.

• Indexes can be created on one or more columns in a table.

• Types of indexes include clustered, non-clustered, unique, and composite indexes.

• Indexes help in quickly locating data without having to scan the entire table.

• Example: Creating an index on the 'employee_id' column in a table of employee records.

The NVL() function is used to replace NULL values with a specified value.

• NVL() is commonly used in SQL queries to handle NULL values.

• It takes two arguments: the value to be checked and the replacement value.

• If the value is NULL, the function returns the replacement value.

• If the value is not NULL, the function returns the original value.

• Example: SELECT NVL(column_name, 'N/A') FROM table_name;

SQL constraints are rules that are applied to a table's columns to ensure data integrity.

• Constraints are used to enforce rules and restrictions on data in SQL tables.

• They help maintain data integrity by preventing invalid or inconsistent data from being inserted or updated.

• Common types of constraints include primary key, foreign key, unique, and check constraints.

• For example, a primary key constraint ensures that each row in a table has a unique identifier.

• Constraints can be ...read more

DBMS stands for Database Management System. It is a software that manages databases and provides an interface for users to interact with the data.

• DBMS is a software that allows users to create, manipulate, and manage databases.

• It provides tools for data storage, retrieval, and organization.

• DBMS ensures data integrity, security, and concurrency control.

• Examples of popular DBMS include MySQL, Oracle, SQL Server, and PostgreSQL.

A self-join is when a table is joined with itself, typically to compare rows within the same table.

• Self-joins are used to compare rows within the same table by creating an alias for the table.

• They are commonly used to retrieve hierarchical data or compare related rows.

• Example: SELECT e1.employee_name, e2.manager_name FROM employees e1 JOIN employees e2 ON e1.manager_id = e2.employee_id

SQL is a programming language used for managing and manipulating relational databases.

• SQL stands for Structured Query Language.

• It is used to communicate with and manage databases.

• SQL allows users to create, modify, and retrieve data from databases.

• It is a standard language for relational database management systems (RDBMS).

• SQL is used for tasks like data insertion, deletion, updating, and querying.

• Examples of popular RDBMS that use SQL include MySQL, Oracle, and SQL Server.

Constraints are rules applied to a database table to enforce data integrity and ensure accuracy.

• Constraints define limits or conditions on the data that can be inserted, updated, or deleted in a table.

• They help maintain data consistency and prevent invalid or inconsistent data from being stored.

• Common types of constraints include primary key, foreign key, unique, not null, and check constraints.

• Examples: A primary key constraint ensures each row in a table has a unique identi...read more

Primary Key is a unique identifier for each record in a database table.

• Primary Key ensures data integrity by enforcing uniqueness and preventing duplicate records.

• It is used to establish relationships between tables in a database.

• Primary Key can be a single column or a combination of multiple columns.

• It is often used as a reference in foreign key constraints.

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

SQL Injection is a code injection technique where an attacker inserts malicious SQL statements into a query to manipulate the database.

• SQL Injection is a common web application vulnerability.

• It occurs when user-supplied input is not properly validated or sanitized.

• Attackers can exploit SQL Injection to bypass authentication, retrieve sensitive data, modify or delete data, or even execute arbitrary commands.

• Preventing SQL Injection involves using parameterized queries or prepa...read more

Tables are structures that store data in a database, while fields are columns within a table that hold specific pieces of information.

• Tables are like spreadsheets with rows and columns

• Fields are the columns in a table that hold specific types of data

• Examples: 'Employees' table with fields like 'Name', 'Age', 'Salary'

UI/UX designers use various tools for design, such as Sketch, Adobe XD, and Figma.

• Sketch is a popular tool used for creating UI designs and prototypes.

• Adobe XD is another widely used tool that allows designers to create interactive prototypes.

• Figma is a collaborative design tool that enables real-time collaboration and prototyping.

• Other tools include InVision, Axure RP, and Marvel.