KEYLOOKUP()
Contents
Purpose
Function to perform a cross-table lookup
Syntax
KEYLOOKUP(<workarea | alias>, <"tagname">, <key expression>, <valueExpr>)
See Also
LOOKUP(), RLOOKUP(), SEEK(), SET RELATION
Description
The KEYLOOKUP() function looks up the specified index <key expression> in the index <tagname> of the specified <workarea | alias>. The KEYLOOKUP() function then evaluates the expression <valueExpr>, and returns the value of the <valueExpr> if the <key expression> is found. The KEYLOOKUP() function returns a null string if the <key expression> is not found.
The current record position in the specified <workarea | alias> cursor is not moved so this function can also safely be used in SQL queries. If the specified <alias> is not already open then Lianja will open the table automatically.
Example
open database southwind use orders in 0 ? keylookup("employees","employeeid",orders.employeeid, employees.lastname)