Tables
Table is a named two-dimensional array of data. Each table consists of a set of named columns and an arbitrary number of unnamed rows.
Table properties:
- Each table in a database has a unique name
- An entry at the intersection of each row and column is atomic (or single-valued). There can be no multi-valued attributes in a table
- Each row is unique; no two rows in a table are identical
- Each attribute (or column) within a table has a unique name.
- The sequence of columns (left to right) is insignificant. The columns of a table can be interchanged without changing the meaning or use of a table.
- The sequence of rows (top to bottom) is insignificant. As with columns, the rows of a table may be interchanged or stored in any sequence.