Main block and misc functions
This section provides details about the MAIN module, the function
implementing the CONSTRUCT instruction and the function fetching rows into the
program array.
Filling program arrays with rows FOREACH instruction can be used to fill program arrays with SQL rows.Example: custlist.4gl types and variables custlist.4gl module defines a couple of types and a module variable to hold the customer records in memory.Example: custlist.4gl (MAIN block) MAIN block implements a WHILE loop, to let the user first enter a query filter, then browse rows in the filtered result set, and repeat the same process until the Cancel button is selected. Example: custlist.4gl (Function custlist_query) CONSTRUCT instruction to get an SQL condition that will be used in the SELECT statement to filter customer table rows.Example: custlist.4gl (Function custarr_fill) custarr_fill function fetches rows from the customer SQL table, according to the SQL condition passed as parameter.