Try this:

lcConnectionStr = "DRIVER={SQL Server};" +;
"SERVER=YourServerName;" +;
"DATABASE=NORTHWIND;" +;
"UID=sa;" +;
"PWD="

nSql = SQLSTRINGCONNECT(lcConnectionStr)

SQLEXEC(nSql, "sp_pkeys [order details]", "pkeys")

This calls the stored procedure sp_pkeys and returns primary key information for the table [order details] into a VFP cursos pkeys.