For different types of connection strings explained in full, please visit https://www.connectionstrings.com 

Here are some examples of connection string formats, however these are not exhaustive. 

MySQL

"Server=[Your_Server_Address]; Database=[Your_Database_Name]; Uid=[Your_Account_Username]; Pwd=[Your_Password];" 

Oracle

"DATA SOURCE=[Your_Server_Address]/[Your_Database_Name]; PASSWORD=[Your_Password]; USER ID=[Your_Username];" 

PostgreSQL

"host=[Your_Server_Address]; Port=[Your_Port]; Database=[Your_Database_Name]; User Id=[Your_Username]; Password=[Your_Password];" 

SQL Server

"Server=[Your_Server_Address]; Database=[Your_Database_Name]; User Id=[Your_Login_Name]; Password=[Your_Password]; Trust Server Certificate=true;"