''jhonemark's blog'': 2009

Wednesday, August 12, 2009

Wednesday, July 15, 2009

...welcome to my blog...........

...............hahahahaha................

Tuesday, July 14, 2009

.........h...........

Thursday, July 9, 2009

Tuesday, June 30, 2009

final fantasy

..h!...all people....

TABLE (database)

Table (database)
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In relational databases and flat file databases, a table is a set of data elements (values) that is organized using a model of vertical columns (which are identified by their name) and horizontal rows. A table has a specified number of columns, but can have any number of rows. Each row is identified by the values appearing in a particular column subset which has been identified as a candidate key.
Table is another term for relations; although there is the difference in that a table is usually a multi-set (bag) of rows whereas a relation is a set and does not allow duplicates. Besides the actual data rows, tables generally have associated with them some meta-information, such as constraints on the table or on the values within particular columns.
The data in a table does not have to be physically stored in the database. Views are also relational tables, but their data are calculated at query time. Another example are nicknames, which represent a pointer to a table in another database.