DbStruct Function (Usual) |  |
Create an array containing the structure of a database file.
Namespace: XSharp.RT
Assembly: XSharp.RT (in XSharp.RT.dll) Version: 2.21
SyntaxRequest Example
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The structure of the database file in an array whose length is equal to the number of fields in the database file.
Each element of the array is a subarray containing information for one field.
The subarrays have the following format:
If there is no database file in use in the work area, DBStruct() will generate
a runtime error.
Parameters
- uArea
- Type: Usual
Specifies the work area name or number for a table from which the value must be retrieved.
Return Value
Type: ArrayThe structure of the database file in an array whose length is equal to the number of fields in the database file.
Each element of the array is a subarray containing information for one field.
The subarrays have the following format:
| Constant | Description |
|---|---|
| DBS_NAME | Returns the name of the field. |
| DBS_TYPE | Returns the data type of the field. |
| DBS_LEN | Returns the length of the field. |
| DBS_DEC | Returns the number of decimal places for the field. |
| DBS_ALIAS | cAlias |
Remarks
DBStruct() operates like COPY STRUCTURE EXTENDED by creating an array of structure
information rather than a database file of structure information.
There is another function, DBCreate(), that can create a database file from the structure array. By default, this function operates on the currently selected work area.
It can be made to operate on an unselected work area by specifying it within an aliased expression
There is another function, DBCreate(), that can create a database file from the structure array. By default, this function operates on the currently selected work area.
It can be made to operate on an unselected work area by specifying it within an aliased expression
Examples
This example opens two database files, then creates an array containing the
database structure using DBStruct() within an aliased expression.
The field attributes are then listed using AEval():
The field attributes are then listed using AEval():
X#
1LOCAL aStruct 2USE customer NEW 3USE invoices NEW 4aStruct := Customer->DBStruct() 5AEval(aStruct, {|aField|QOut(aField[DBS_NAME]),; 6QOut(aField[DBS_TYPE]), QOut(aField[DBS_LEN]),; 7QOut(aField[DBS_DEC]), QOut(aField[DBS_ALIAS])})
See Also