SQL Table

A SQL Table is a tabular data structure that supports SQL table operations.

• Context:
  • It can be created with a SQL CREATE TABLE command.
  • It can be deleted with a SQL DROP TABLE command.
  • It can be updated with a SQL UPDATE TABLE command.
  • It can be appended to with a SQL INSERT TABLE command.
• Example(s):
  • a Postgres Table.
  • a MySQL Table.
  • …
• Counter-Example(s):
  • a pandas.DataFrame Table.
  • an Excel Worksheet.
• See: SQL Query.

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References

2014

• http://en.wikipedia.org/wiki/Table_(database)#Tables_versus_relations
  • In terms of the relational model of databases, a table can be considered a convenient representation of a relation, but the two are not strictly equivalent. For instance, an SQL table can potentially contain duplicate rows, whereas a true relation cannot contain duplicate tuples. Similarly, representation as a table implies a particular ordering to the rows and columns, whereas a relation is explicitly unordered. However, the database system does not guarantee any ordering of the rows unless an ORDER BY clause is specified in the SELECT statement that queries the table.

    An equally valid representations of a relation is as an n-dimensional chart, where n is the number of attributes (a table's columns). For example, a relation with two attributes and three values can be represented as a table with two columns and three rows, or as a two-dimensional graph with three points. The table and graph representations are only equivalent if the ordering of rows is not significant, and the table has no duplicate rows.

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