How to set SQL Server database in Emergency mode? Why do we need to set SQL Server database in Emergency mode?

a) How to set SQL Server database in Emergency mode?

There are different ways that you set SQL Server Database in Emergency mode, however this article will illustrate using T-SQL Database configuration statement
               T-SQL:
Alter database Your_database_name Set Emergency


b) Why do we need to set SQL Server database in Emergency mode?
Sometimes you run into a situation when you don't have good backup or backup of database is corrupted. Your database went into suspect mode due corrupt log or data in the database. Emergency mode is one of the database recovery technique used to repair the data lose or rebuild the log so that you can bring the database in recoverable state and online.
It is sort of tricking the system tables to put the database in emergency mode so that you can perform all the repairs in order to recover the database.