提示變量值時恢復掃描狀態

Question

如何檢測當前的SCAN狀態並在更改後恢復它？

從腳本中的問題exerpt：

SET SCAN OFF 
SET ECHO ON 
SET SQLBLANKLINES ON 

SET SCAN ON 
UPDATE TABLE_NAME SET CREATED_BY = &&created_by; 
SET SCAN OFF 

的問題是，如果腳本不具有第一行（SET SCAN OFF），則提示用戶的代碼不應該打開SCAN狀態之後關閉。僞代碼解決方案：

-- The next line might not exist, or be "SET SCAN ON". 
SET SCAN OFF 
SET ECHO ON 
SET SQLBLANKLINES ON 

-- Remember if the scanning was on or off. 
PUSH SCAN STATE 
SET SCAN ON 
UPDATE TABLE_NAME SET CREATED_BY = &&created_by; 

-- Revert scanning to its former state. 
POP SCAN STATE 

線PUSH SCAN STATE記得狀態，如果代碼被刪除的第一行改變時，腳本的其餘部分仍然按預期工作，由於corresonding POP SCAN STATE。

Answer 1

的SQL 加STORE命令應該做到這一點，不幸的是它似乎並沒有保存SCAN狀態（SQL加9.2.0.1.0）。我將與其它設置（TIMING）證明：

SQL> show timing 
timing OFF 
SQL> -- save parameters into an os file 
SQL> store set param.sql create 
Created file param.sql 
SQL> -- run script 
SQL> SET TIMING ON 
SQL> show timing 
timing ON 
SQL> -- reset state 
SQL> @param.sql 
SQL> show timing 
timing OFF