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SQL Basic and fundamental concepts SQL is a language for managing data in a database. SQL stands for Structured Query Language. SQL is used to create, modify, retrieve and delete data from a database. SQL works with relational databases. A relational database is a collection of data organized into tables. Each table has rows and columns of data. The rows are called records or tuples, and the columns are called attributes or fields. The tables in a relational database are related to each other by common attributes. The structure of the tables in a relational database is called the schema or model of the database. The schema defines how information is stored in the database, including what tables exist, how they relate to each other, what their attributes are and what value types they contain (e.g., numeric, character string). SQL statements can be written interactively through an interactive tool called SQL*Plus that comes with Oracle Database software; or they can be embedded in an app...