Table Iterator
A table iterator is used when you have created a table object and you have to iterate over all the rows or a specific subset of the rows in the table.
You can create a table iterator to query the contents of the table and then iterate over the query results. Using a NULL filter string when creating the table iterator returns all of the rows of the table. Providing a non-NULL filter string when creating a table iterator controls the rows of a table that are included in the query results for the iterator.
The filter string format follows the syntax of the WHERE clause of a SQL SELECT statement excluding the WHERE keyword as shown in the following example:
When applied to a row of the table, the filter string results in a boolean value indicating whether or not a row must be included in the results of a query. See The WHERE Clause.
The results of a query using a table iterator contain all columns of a table rather than a subset of specific columns. That is, all queries using a table iterator implicitly begin with SELECT * FROM table_name WHERE. Nonetheless, programs do not specify this string, they specify only the filter that would follow the WHERE keyword.
Application programs cannot influence the order of the results.