How to Retrieve Table Properties in a Program

ID: Q130604

3.00 WINDOWS

The information in this article applies to:

Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

Visual FoxPro introduces new table properties (triggers, validation rules, and comments) that are available to fields in tables that belong to databases. This article describes how to look up these table properties by using a program.

MORE INFORMATION

The new properties are available only if the table belongs to a database. You can use the DISPLAY DATABASE and LIST DATABASE commands to view, list to a file, or print all the table properties. The following examples apply only to the case where you want a program to retrieve the table properties to store in variables or for some other purpose.

Validation Rule

Use the AFIELDS() or DBGETPROP() function to obtain the value of the Validation Rule table property.

AFIELDS() places information about the table structure into an array. The syntax for AFIELDS() is:

   cResult=AFIELDS(ArrayName[,TableName | WorkArea])

Parameters:

ArrayName specifies a pre-existing array or a new array.
TableName or WorkArea is optional. if a table name or work area is not provided, Visual FoxPro populates the array with data from the current work area.

AFIELDS() creates a multi-dimensional array, the Validation Rule is stored in column 10. The following example retrieves the Validation Rule from a table named MYDATA.DBF:

   cResult=AFIELDS(myarray,mydata)
   ?myarray(1,10)

DBGETPROP() retrieves several table properties. The following example shows how to return the Validation Rule of a table by using the DBGETPROP() function:

   cResult=DBGETPROP('mydata', 'TABLE', 'RuleExpression')

In this example:

mydata is the table name.
TABLE specifies that the property you want is a table property.
RuleExpression is the property you want.

Validation Text

Use the AFIELDS() or DBGETPROP() function to obtain the value for the Validation Text table property.

AFIELDS() creates a multi-dimensional array, the Validation Text is stored in column 11. The following example retrieves the Validation Text for a table named MYDATA.DBF:

   cResult=AFIELDS(myarray,mydata)
   ?myarray(1,11)

The following example shows how to return the Validation Text of a table by using the DBGETPROP() function:

   cResult=DBGETPROP('mydata', 'TABLE', 'RuleText')

Insert Trigger

Use the DBGETPROP() function to obtain the Insert Trigger, as in this example:

   cResult=DBGETPROP('mydata', 'TABLE', 'InsertTrigger')

Update Trigger

Use the DBGETPROP() function to obtain the Update Trigger, as in this example:

   cResult=DBGETPROP('mydata', 'TABLE', 'UpdateTrigger')

Delete Trigger

Use the DBGETPROP() function to obtain the Delete Trigger, as in this example:

   cResult=DBGETPROP('mydata', 'TABLE', 'DeleteTrigger')

Table Comments

Use the DBGETPROP() function to obtain the Table Comments:

   cResult=DBGETPROP('mydata', 'TABLE', 'Comment')

Primary Key

Use the DBGETPROP() function to obtain the tag name of a Primary key, as in this example:

   cResult=DBGETPROP('mydata', 'TABLE', 'PrimaryKey')

Path

Use the DBGETPROP() or DBF() function to obtain the path to the table. The following example shows how to return the path of a table by using the DBGETPROP() function:

   cResult=DBGETPROP('mydata', 'TABLE', 'Path')

To obtain the path to a table by using the DBF() function, SET FULLPATH must be used, as in this example:

   SET FULLPATH ON
   cResult=DBF('mydata')

Additional reference words: 3.00 VFoxWin KBCategory: KBSubcategory: FxprgTable

Keywords          : kbcode FxprgTable 
Version           : 3.00
Platform          : WINDOWS