How to install a second instance of SQL Server?
During the first installation of SQL Server, there are two options for the instances, te first option is to install the default instance, the other option is to install a named instance. To install another instance, follow the steps below and adapt according to the SQL Server configuration.
Add multiple additional instances to a SQL Server
To do this, run the installation from the executable and install the new instance of the RDBMS : SQL Server Database Engine. With a SQL Server Developer, Standard or Enterprise version, SQL Server names the instance MSSQLSERVER by default. However, the name of the named instance is free.
One default instance named MSSQLSERVER per server
Furthermore, with the SQL Server Express Edition, run the installer twice. Then rename the new instance with a name other than the default instance, i.e. SQLExpress. If installing an additional database instance is impossible, then an interesting alternative is to create another database in the existing instance!
Indeed, simply use SQL Server Management Studio with the right privileges or a SQL script. To go further, find out here how to create a database using SSMS and no SQL script. When connecting to a default instance, specifying the instance name is not necessary.
To create a new database instance with SQL Server, you just have to restart the SQL Server installation utility and choose a named instance.
In SQL Server, the default instance which is installed at first, is named MSSQLSERVER.
The default listening port in SQL Server is the 1433 port number. Change it using the SQL Server Configuration Manager tool available on the server hosting your instance.
To conclude, it is possible to easily install a new instance with SQL Server 2019 for example.