Access Number Data Type Field Sizes
As promised to a group of trainees (you know who you are!) on a recent Access training course with me, here are the relevant field size allocations for the various Number data format types, as used in Access 2003. I hope it helps… J
If the DataType property is set to Number, the FieldSize property settings and their values are related in the following way:
|Setting||Description||Decimal precision||Storage size|
|Byte||Stores numbers from 0 to 255 (no fractions).||None||1 byte|
|Decimal||Stores numbers from –10^38–1 through 10^38–1 (.adp)Stores numbers from –10^28–1 through 10^28–1 (.mdb)||28||12bytes|
|Integer||Stores numbers from –32,768 to 32,767 (no fractions).||None||2 bytes|
|Long Integer||(Default) Stores numbers from –2,147,483,648 to 2,147,483,647 (no fractions).||None||4 bytes|
|Single||Stores numbers from–3.402823E38 to –1.401298E–45for negative values and from1.401298E–45 to 3.402823E38 for positive values.||7||4 bytes|
|Double||Stores numbers from–1.79769313486231E308 to–4.94065645841247E–324for negative values and from
1.79769313486231E308 for positive values.
|Replication ID||Globally unique identifier (GUID (GUID: A 16-byte field used in an Access database to establish a unique identifier for replication. GUIDs are used to identify replicas, replica sets, tables, records, and other objects. In an Access database, GUIDs are referred to as Replication IDs.))||N/A||16 bytes|
Remember that this property can only be set from the table’s property sheet.