What do you understand by the term foreign key?

A foreign key is specified as a key which is related to the primary key of another table. A relationship needs to be created between two tables by referencing foreign key with the primary key of another table. Foreign key acts like a cross-reference between tables as it refers to the primary key of other table and the primary key-foreign key relationship is a very crucial relationship as it maintains the ACID properties of database sometimes. 

Mon Dec 3,2018

What do you understand by the term primary key?

A primary key is a combination of fields which uniquely specify a row. This is a special kind of unique key, and it has implicit NOT NULL constraint. It means, Primary key values should be UNIQUE and NOT NULL.  

Mon Dec 3,2018

What is the difference between DROP and TRUNCATE commands in sql?

TRUNCATE command removes all rows from the table which cannot be retrieved back, DROP command delete the entire table from the database and it cannot be retrieved back. 

Mon Dec 3,2018

What do you understand by the term stored procedure?

A stored procedure is a collection of SQL statements which can be used as a function to access the database. We can create these stored procedures previously before using it and can execute these them wherever we require and also apply some conditional logic to it. Stored procedures are also used to reduce network traffic and improve the performance.

Syntax: CREATE Procedure Procedure_Name
(
//Parameters
)
AS
BEGIN
SQL statements in stored procedures to update/retrieve records
END 

Mon Dec 3,2018

What do you understand by the term SQL?

SQL stands for Structured Query Language , and it is used to communicate with the Database. It is an American National Standard Institute (ANSI) standard. This is a standard language used to perform tasks such as retrieval, updation, insertion and deletion of data from a database.  

Mon Dec 3,2018
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