Difference between revisions of "Databases"
From Suhrid.net Wiki
Jump to navigationJump to search| Line 12: | Line 12: | ||
* Standard for data representation and exchange | * Standard for data representation and exchange | ||
* Document format similar to HTML, however tags represent content instead of formatting. | * Document format similar to HTML, however tags represent content instead of formatting. | ||
| + | * XML consists of tagged elements which can be nested, attributes of elements and the text (values/data) | ||
| + | * XML document can be thought of as a tree with values/text forming the leaves. | ||
Revision as of 22:55, 7 December 2013
Relational Databases
- Set of named relations (tables)
- Each relation has a set of named attributes (columns)
- Each tuple (row) has a value for each attribute
- Each attribute has a type (or domain)
- All queries return relations (tables), so it can said to be compositional or closed.
XML Data
- Alternative to relational model to store data
- Standard for data representation and exchange
- Document format similar to HTML, however tags represent content instead of formatting.
- XML consists of tagged elements which can be nested, attributes of elements and the text (values/data)
- XML document can be thought of as a tree with values/text forming the leaves.
