mPHATEK Systems Junior Software Engineer Interview Questions and Answers

Delete removes rows from a table, truncate removes all rows from a table, drop removes a table from the database.

• Delete is a DML command which removes specific rows from a table.

• Truncate is a DDL command which removes all rows from a table but keeps the table structure.

• Drop is a DDL command which removes an entire table from the database.

• Delete can be rolled back, truncate cannot be rolled back, drop cannot be rolled b...read more

Types of joins in SQL include inner join, outer join, left join, and right join.

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

• Outer join: returns all rows when there is a match in one of the tables

• Left join: returns all rows from the left table and the matched rows from the right table

• Right join: returns all rows from the right table and the matched rows from the left table

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

• Normalization involves breaking down data into smaller, more manageable tables

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

• Normalization ensures data integrity by avoiding update anomalies

• There are different normal forms like 1NF, 2NF, 3NF, etc.

• Example: In a database, instead of stori...read more