In a relational database, what are a table, a row and a column?
Options
- A table is a file; a row is a folder; a column is a disk
- Table: a kind of data. Row: a record. Column: an attribute (Correct option)
- A row is a database; a column is a user of the database
- They are all the same thing, with three different names
Answer
A table holds one kind of data; each row is one record (e.g. one customer); each column is one attribute (e.g. email) with a fixed type
Why
A relational database organizes data in tables, like spreadsheets with strict rules.
- Table: a collection about one thing (
customers). - Row (record): one item (customer 17).
- Column (field): one property of every item with a data type (
email VARCHAR,age INT).
Tables are linked with keys: a primary key identifies each row, and a foreign key in another table points to it.
Remember
Table = entity, row = record, column = attribute.