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[Ruey]

Building a Data Dictionary
How do you create a cursor in the Load event? You could hard-code the creation of each cursor, but there’s a better way: You can use a Data Dictionary that contains the information needed to build the cursor, then call the CreateCursor() function described below.

The Data Dictionary table looks like this:

Listing 7 - The DataDict table for creating cursors as needed

DATADICT.DBF:
CursorName Character(30),
FieldName Character(30),
FieldType Character(10),
FieldLen Numeric ( 3),
Decimals Numeric ( 1)
I’ve written a little program to make it easy for you to add your existing DBFs to the Data Dictionary table:

Listing 8 - Program to add a DBF’s structure to the DataDict table

Program-ID... ..:Add2DD.PRG
Purpose.........: Adds a table’s fields to the DataDict table
IF EMPTY ( ALIAS() )
MessageBox ( [No table is open in the current work area], 64 )
RETURN
ENDIF
NewAlias = ALIAS()
=AFIELDS( FA )
FOR I = 1 TO ALEN ( FA )
INSERT INTO DataDict VALUES ( ;
NewAlias, FA(I,1), FA(I,2), FA(I,3), FA(I,4) )
ENDFOR
The CreateCursor function follows. Note that the Create Cursor command requires an array with 16 columns, since that’s the number of columns in arrays created by AFIELDS() function:

Listing 9 - Program to create a local cursor using a structure from DataDict

* Program-ID...: CreateCursor.PRG
* Purpose......: Creates a cursor from a tablename
PARAMETERS CurName
SELECT FieldName, FieldType, FieldLen, Decimals FROM DataDict ;
WHERE ALLTRIM(UPPER(CursorName)) == ALLTRIM(UPPER(CurName))INTO ARRAY CurDef
IF TYPE ( [CurDef(1)] ) = [U]
Msg = [Programmer error:] + CHR(13) ;
+ CurName
+ [ fields not found in data dictionary]
MESSAGEBOX( Msg, 64, _VFP.Caption )
ENDIF

DIMENSION CA ( ALEN(CurDef,1), 16 )
STORE [] TO CA
FOR I = 1 TO ALEN ( CA,1)
CA(I,1) = ALLTRIM(CurDef(I,1))
CA(I,2) = ALLTRIM(CurDef(I,2))
CA(I,3) = CurDef(I,3)
CA(I,4) = CurDef(I,4 )
CA(I,5) = .F.
CA(I,6) = .F.
ENDFOR
CREATE Cursor &CurName FROM ARRAY CA
USE EXCL
RELEASE CA, CurDef
IF USED ( [DataDict] )
USE IN DataDict
ENDIF