Null

Null : The absence of a data value in a data field or data element. The value may exist for the characteristic of the real world object or event and is missing or unknown, or there may be no value (called "empty") because the characteristic does not exist in the real world object or event. 

[Category=Data Quality ]

Source: Larry English, http://www.iaidq.com/main/glossary.shtml , 03-Feb-2009 13:45

---

These advertisers support this free service

---

Null; Null Value - If a field contains a data item, that has a specific value. A field that does not contain a data item is said to have a null value. In a numeric field, a null value is not the same as a value of zero; in a character field, a null value is not the same as a blank - both the numeric zero and blank character are definite values. A null value indicates that the that the field's value is undefined - it's value is not known.

[Category=Database Management ]

Source: Northwest Database Services, 12 November 2009 11:07:23, http://www.nwdatabase.com/database-glossary-n.htm

---

Null - A null value tells you the value for that row is either missing, unknown, not yet know or inapplicable. Placing a zero in the row would not reflect the accurate state of the row, because zero is a value. This way you can search for missing data and SQL supports the notion of null values.

[Category=Information Management ]

Source: Information-Management.com, 29 June 2010 08:12:20, http://www.information-management.com/glossary/m.html