Form Query Process Flow(F11 -> Ctrl+F11)

F11查询过程：

1)WHEN-CLEAR-BLOCK

2)WHEN-NEW-RECORD-INSTANCE

3)WHEN-NEW-ITEM-INSTANCE

在输入查询条件后点CTRL+F11：

4)PRE-QUERY

Provide additional query criteria programmatically, just before sending the SELECT statement to the database.

Sample Code:
If :parameter.G_query_find = 'TRUE' then
:trans_reasons.reason_id := :parameter.trans_reasons_qf;
:parameter.G_query_find := 'FALSE';
end if;

5)WHEN-CLEAR-BLOCK

6)POST-QUERY

Perform an action after fetching a record, such as looking up values in other tables based on a value in the current record. Fires once for each record fetched into the block.

在返回查询结果之后的做的动作，例如根据现在的查询结果去其他关联表中再查，再每个record塞进block的时候触发。每查一条记录，触发一次。

7)WHEN-NEW-RECORD-INSTANCE

8)WHEN-NEW-ITEM-INSTANCE