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How to connect multiple database in java
I am working on projects where I wanted to connect multiple database to a single application it is possible or not if possible them how.
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Primary Keys
A primary key is a field in the table that uniquely identifies the table records.
The primary key's main features:
- It must contain a unique value for each row.
- It cannot contain NULL values.
For example, our table contains a record for each name in a phone book. The unique ID number would be a good choice for a primary key in the table, as there is always the chance for more than one person to have the same name.