📅 最后修改于: 2020-11-20 05:21:27 🧑 作者: Mango
表中的每个字段都有属性，这些属性定义了字段的特征和行为。字段最重要的属性是其数据类型。字段的数据类型决定了它可以存储哪种数据。 MS Access支持不同类型的数据，每种类型都有特定的用途。
以下是在典型的Microsoft Access数据库中可以找到的一些最常见的数据类型。
| Type of Data | Description | Size |
|---|---|---|
| Short Text | Text or combinations of text and numbers, including numbers that do not require calculating (e.g. phone numbers). | Up to 255 characters. |
| Long Text | Lengthy text or combinations of text and numbers. | Up to 63, 999 characters. |
| Number | Numeric data used in mathematical calculations. | 1, 2, 4, or 8 bytes (16 bytes if set to Replication ID). |
| Date/Time | Date and time values for the years 100 through 9999. | 8 bytes |
| Currency | Currency values and numeric data used in mathematical calculations involving data with one to four decimal places. | 8 bytes |
| AutoNumber | A unique sequential (incremented by 1) number or random number assigned by Microsoft Access whenever a new record is added to a table. | 4 bytes (16 bytes if set to Replication ID). |
| Yes/No | Yes and No values and fields that contain only one of two values (Yes/No, True/False, or On/Off). | 1 bit. |
如果使用早期版本的Access，您会注意到其中两种数据类型有所不同。
在Access 2013中，我们现在有两种数据类型-短文本和长文本。在早期版本的Access中，这些数据类型称为文本和备注。
该文本字段称为短文本，而您的备注字段现在称为长文本。
这是一些其他更特殊的数据类型，您可以在Access中选择。
| Data Types | Description | Size |
|---|---|---|
|
Attachment |
Files, such as digital photos. Multiple files can be attached per record. This data type is not available in earlier versions of Access. |
Up to about 2 GB. |
|
OLE objects |
OLE objects can store pictures, audio, video, or other BLOBs (Binary Large Objects) |
Up to about 2 GB. |
|
Hyperlink |
Text or combinations of text and numbers stored as text and used as a hyperlink address. |
Up to 8,192 (each part of a Hyperlink data type can contain up to 2048 characters). |
|
Lookup Wizard |
The Lookup Wizard entry in the Data Type column in the Design view is not actually a data type. When you choose this entry, a wizard starts to help you define either a simple or complex lookup field. A simple lookup field uses the contents of another table or a value list to validate the contents of a single value per row. A complex lookup field allows you to store multiple values of the same data type in each row. |
Dependent on the data type of the lookup field. |
|
Calculated |
You can create an expression that uses data from one or more fields. You can designate different result data types from the expression. |
You can create an expression that uses data from one or more fields. You can designate different result data types from the expression. |
这些都是在Microsoft Access表中创建字段时可以选择的所有不同数据类型。