PL/SQL is a proprietary extension of SQL, or Structured Query Language, sold by Oracle Corporation. It adds procedural language features to SQL, giving the ability to programmatically parse data within SQL. While this deviates from a SQL’s purpose as an implementation of relational algebra, a system designed to describe the relationships between things, it’s a practical addition, because most programmers end up parsing SQL in their programming language of choice anyway.
Open the SQL console. This is done by running PL/SQL at the console.
Since PL/SQL is primarily used in the server environment, you should have a console running by default.
Log in to the database using your credentials. Often, the default username will be “root” and the password field should be left blank.
You can query multiple databases by prefixing the database name before the tables you’d like to query.
“Select all from TestDatabase.TestTable and TestDatabase2.TestTable where id =1.”