WHERE-STRING attribute

Returns and allows you to modify the current WHERE expression from the query generated for a specified data-relation that links the child table to its parent.

This attribute evaluates to the WHERE expression from the query that the AVM generates for you based on the data-relation between parent and child buffers. You can also use this attribute to build an extended query of your own based on this default relationship.

If you assign a new value to the attribute, the AVM uses the new WHERE expression when it re-opens the query during navigation to filter the child table of the data-relation. When you set this attribute, if the AVM finds an error in the new WHERE expression, it raises a run-time error on the assignment.

The NAME attribute of the Temp-table object handle is writeable for dynamic and AVM-generated temp-tables. You might need to update a WHERE-STRING that references a renamed temp-table with new strings using the new table name.

Typically, you modify an existing WHERE expression by appending additional conditions to it, as shown in the r-wherestr.p example procedure. This example provides the initial WHERE expression using the FILL-WHERE-STRING attribute. It then generates the complete initial query for the data-relation with the call to the ProDataSet FILL( ) method, and uses the WHERE-STRING attribute to modify the existing WHERE expression to further filter the query buffers.

r-wherestr.p
DEFINE TEMP-TABLE ttCus LIKE Customer. DEFINE TEMP-TABLE ttOrder LIKE Order. DEFINE DATASET dsCus FOR ttCus,ttOrder DATA-RELATION dr1 FOR ttCus, ttOrder RELATION-FIELDS(CustNum,CustNum). DEFINE DATA-SOURCE dscCus FOR Customer. DEFINE DATA-SOURCE dscOrd FOR Order. DEFINE QUERY q1 FOR ttCus. DEFINE QUERY q2 FOR ttOrder. DEFINE BROWSE b1 QUERY q1 DISPLAY ttCus.CustNum ttCus.Name ttCus.Address WITH 3 DOWN. DEFINE BROWSE b2 QUERY q2 DISPLAY ttOrder.CustNum ttOrder.OrderNum ttOrder.ShipDate WITH 6 DOWN. BUFFER ttCus:ATTACH-DATA-SOURCE(DATA-SOURCE dscCus:HANDLE). BUFFER ttOrder:ATTACH-DATA-SOURCE(DATA-SOURCE dscOrd:HANDLE). DATA-SOURCE dscCus:FILL-WHERE-STRING = "WHERE CustNum < 3". DATASET dsCus:FILL( ). `DATASET dsCus:GET-RELATION(1):WHERE-STRING` `= DATASET dsCus:GET-RELATION(1):WHERE-STRING` `+ " AND ttOrder.OrderNum < 100".` /* Shows full dataset / FOR EACH ttCus: DISPLAY ttCus.CustNum. FOR EACH ttOrder OF ttCus: DISPLAY ttOrder.OrderNum ttOrder.OrderDate. END. END. BROWSE b1:QUERY = DATASET dsCus:TOP-NAV-QUERY. BROWSE b2:QUERY = DATASET dsCus:GET-RELATION(1):QUERY. / Shows only filtered records */ ENABLE b1 b2 WITH FRAME frX ROW 1 SIZE 70 BY 30. WAIT-FOR WINDOW-CLOSE OF CURRENT-WINDOW.

DEFINE TEMP-TABLE ttCus LIKE Customer. 
DEFINE TEMP-TABLE ttOrder LIKE Order. 
DEFINE DATASET dsCus FOR ttCus,ttOrder DATA-RELATION dr1 
  FOR ttCus, ttOrder RELATION-FIELDS(CustNum,CustNum). 
DEFINE DATA-SOURCE dscCus FOR Customer. 
DEFINE DATA-SOURCE dscOrd FOR Order. 
DEFINE QUERY q1 FOR ttCus. 
DEFINE QUERY q2 FOR ttOrder. 
DEFINE BROWSE b1 QUERY q1  
  DISPLAY ttCus.CustNum ttCus.Name ttCus.Address WITH 3 DOWN. 
DEFINE BROWSE b2 QUERY q2  
  DISPLAY ttOrder.CustNum ttOrder.OrderNum ttOrder.ShipDate WITH 6 DOWN. 
BUFFER ttCus:ATTACH-DATA-SOURCE(DATA-SOURCE dscCus:HANDLE). 
BUFFER ttOrder:ATTACH-DATA-SOURCE(DATA-SOURCE dscOrd:HANDLE). 
DATA-SOURCE dscCus:FILL-WHERE-STRING = "WHERE CustNum < 3". 
DATASET dsCus:FILL( ). 
DATASET dsCus:GET-RELATION(1):WHERE-STRING  
  = DATASET dsCus:GET-RELATION(1):WHERE-STRING  
    + " AND ttOrder.OrderNum < 100".  
/* Shows full dataset */ 
FOR EACH ttCus: 
  DISPLAY ttCus.CustNum. 
  FOR EACH ttOrder OF ttCus: 
    DISPLAY ttOrder.OrderNum ttOrder.OrderDate. 
  END. 
END. 
BROWSE b1:QUERY = DATASET dsCus:TOP-NAV-QUERY. 
BROWSE b2:QUERY = DATASET dsCus:GET-RELATION(1):QUERY. 
/* Shows only filtered records */ 
ENABLE b1 b2 WITH FRAME frX ROW 1 SIZE 70 BY 30. 
WAIT-FOR WINDOW-CLOSE OF CURRENT-WINDOW.