First, the boring part:
From: [URL unfurl="true"]http://en.wikipedia.org/wiki/Relational_database[/url]
A relational database is a database that has a collection of tables of data items, all of which is formally described and organized according to the relational model.
In the relational model, each table schema must identify a column or group of columns, called the primary key, to uniquely identify each row. Rows in one table can relate to rows in another table by establishing a foreign key, a column or group of columns in one table that points to the primary key of another table. The relational model offers various levels of refinement of table organization and reorganization called database normalization.
From: [URL unfurl="true"]http://en.wikipedia.org/wiki/Table_(database)[/url]
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, the cell being the unit where a row and column intersect. 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 unique key index.
Table is another term for relations; although there is the difference in that a table is usually a multiset (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 metadata, such as constraints on the table or on the values within particular columns.
Now, the question:
If all (so called) ‘tables’ in the database ignore and break pretty much all the rules of being the “relational databases’ tables” (no PK, no FK, no constrains, no normalization, etc.), can they still be called ‘tables’?
And going even further, if those are NOT tables, do we still have a “relational database” or even just a database?
In other words, if we have a data in unrelated (for the lack of a better word) spreadsheets, where you can add or update any row with anything, even insert whole empty rows (all fields can be NULLs) – is it still called relational database?
Have fun.
---- Andy
From: [URL unfurl="true"]http://en.wikipedia.org/wiki/Relational_database[/url]
A relational database is a database that has a collection of tables of data items, all of which is formally described and organized according to the relational model.
In the relational model, each table schema must identify a column or group of columns, called the primary key, to uniquely identify each row. Rows in one table can relate to rows in another table by establishing a foreign key, a column or group of columns in one table that points to the primary key of another table. The relational model offers various levels of refinement of table organization and reorganization called database normalization.
From: [URL unfurl="true"]http://en.wikipedia.org/wiki/Table_(database)[/url]
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, the cell being the unit where a row and column intersect. 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 unique key index.
Table is another term for relations; although there is the difference in that a table is usually a multiset (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 metadata, such as constraints on the table or on the values within particular columns.
Now, the question:
If all (so called) ‘tables’ in the database ignore and break pretty much all the rules of being the “relational databases’ tables” (no PK, no FK, no constrains, no normalization, etc.), can they still be called ‘tables’?
And going even further, if those are NOT tables, do we still have a “relational database” or even just a database?
In other words, if we have a data in unrelated (for the lack of a better word) spreadsheets, where you can add or update any row with anything, even insert whole empty rows (all fields can be NULLs) – is it still called relational database?
Have fun.
---- Andy