AFIELDS( ) Function
Retrieves and stores information about the structure of the table in a specified work area, specified by a table alias, or in the currently selected work area in an array and returns the number of fields in the table.
AFIELDS( ArrayName [, nWorkArea | cTableAlias ] )
Parameters
ArrayName
Specifies an array to store information about the table structure.If the array you specify does not exist, Visual FoxPro automatically creates it. If the array exists and is not large enough to contain all the information returned by AFIELDS( ), the size of the array is automatically increased to accommodate the information.
- nWorkArea
Specifies the work area of the table.
cTableAlias
Specifies a table alias.If you omit nWorkArea and cTableAlias, AFIELDS( ) retrieves information for the table in the currently selected work area.
Return Value
Numeric data type. AFIELDS( ) returns the number of fields in the table. The array contains 18 columns and has the same number of rows as fields in the table.
The following table describes the content of each column in the first row of the array and the data type of the information stored in each column. Values for table-specific properties in columns 10 through 16 only appear in the first row of the array. One row is created for each field in the table.
| Column number | Field info | Data type |
|---|---|---|
1 |
Field name |
Character |
2 |
Field type: C = Character Y = Currency D = Date T = DateTime B = Double F = Float G = General I = Integer L = Logical M = Memo N = Numeric Q = Varbinary V = Varchar and Varchar (Binary) W = Blob |
Character |
3 |
Field width |
Numeric |
4 |
Decimal places |
Numeric |
5 |
Null values allowed |
Logical |
6 |
Code page translation not allowed |
Logical |
7 |
Field validation expression |
Character |
8 |
Field validation text |
Character |
9 |
Field default value |
Character |
10 |
Table validation expression |
Character |
11 |
Table validation text |
Character |
12 |
Long table name |
Character |
13 |
Insert trigger expression |
Character |
14 |
Update trigger expression |
Character |
15 |
Delete trigger expression |
Character |
16 |
Table comment |
Character |
17 |
NextValue for autoincrementing |
Numeric |
18 |
Step for autoincrementing |
Numeric |
Remarks
If the fields in the table use autoincrementing, the Step value is greater than 0.
You can use COPY STRUCTURE EXTENDED to place similar information into a table instead of an array.
Example
The following example creates an array named gaMyArray, which contains information about the fields in the Customer table. The names of the fields are displayed.
CLOSE DATABASES
OPEN DATABASE (HOME(2) + 'Data\testdata')
USE Customer && Open Customer table.
gnFieldcount = AFIELDS(gaMyArray) && Create array.
CLEAR
FOR nCount = 1 TO gnFieldcount
? gaMyArray(nCount,1) && Display field names.
ENDFOR
See Also
Reference
ADEL( ) Function
ADIR( ) Function
AELEMENT( ) Function
AINS( ) Function
ALEN( ) Function
ALTER TABLE - SQL Command
ASCAN( ) Function
ASORT( ) Function
ASUBSCRIPT( ) Function
COPY STRUCTURE EXTENDED Command
CREATE Command
CREATE TABLE - SQL Command
DIMENSION Command
Visual FoxPro Data and Field Types
Concepts
Autoincrementing Field Values in Tables