Question

I have two sql tables called scan_sc and rescan_rsc. The scan table looks like this:

CREATE TABLE scan_sc 
( 
   id_sc int(4), 
   Type_sc varchar(255), 
   ReScan_sc varchar(255), 
   PRIMARY KEY  (id_sc)
)

When a scan a document I insert a row into the scan table. If the result of this scanning is poor I have to do a rescan, and therefore I have a rescan table.

CREATE TABLE rescan_rsc 
(
   id_rsc int(4), 
   Scan_rsc varchar(255), 
   PRIMARY KEY  (id_rsc)
)

The problem is, I want to have a trigger that will fill in the column ReScannet_sc with an "x", in the scan_sc table, so I can see that there has been some problems here.

The trigger has to do it where the id from the rescan table is the same as in the scan table.

Hope you all understand my question.

Thanks in advance.

Answer 1

Do you really need the ReScan_sc column and the trigger?

With a simple JOIN, you can find out the records in your scan_sc table that have been re-scanned, without using the ReScan_sc column at all.
There are several possibilities:

Show all scans, with an additional column with the Rescan ID, if any:

SELECT scan_sc.*, rescan_sc.id_rsc
FROM scan_sc
LEFT JOIN rescan_sc ON scan_sc.id_sc = rescan_sc.id_rsc

Show only the scans which have been re-scanned:

SELECT scan_sc.*
FROM scan_sc
INNER JOIN rescan_sc ON scan_sc.id_sc = rescan_sc.id_rsc

(I assume that id_sc and id_rsc are the primary keys and that PRIMARY KEY (id_sd) is a typo, like marc_s pointed out in his comment)