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What is a Composite Key ?

A Composite primary key is a set of columns whose values uniquely identify every row in a table. What it means is that, table which contains composite primary key will be indexed based on columns specified in the primary key. This key will be referred in Foreign Key tables. For example – if combined effect

What is a Foreign Key ?

A primary key is a column whose values uniquely identify every row in a table. Primary key values can never be reused. If a row is deleted from the table, its primary key may not be assigned to any new rows in the future. To define a field as primary key, following conditions had to

What are properties of a transaction?

What is a Database Lock ?

What is a database transaction?

What is a Record in a database ?

What is a Table in a database ?

what is a field in a database ?