Update trigger in oracle on updating a column Pretoria udult date
Syntax could also use the keyword ALWAYS instead of DEFAULT On UPDATE.This might be a bit more in line with the current logic.
Thus, one should NEVER create an UPDATE trigger on a BLOB column, since it isn't reliable.
Now I need that feature for the blobs too -but it seems it is very difficult. However, you can use a LOB in the body of a trigger as follows:- in regular triggers old values may be read but not written and new values may not be read nor written.- in 'instead of triggers', the:old and:new values can be read but not written.o dbms_lob.write (and other dbms_lob calls) do not fire a trigger -- people can and will change the value of a blob and you will not be able to detect it with a trigger.
In order to update a LOB, I might never issue an UPDATE. I am a DBA for a large development team, and just received some new ddl that has a table with 2 blob columns.
Likewise, use of a view in combination with an INSTEAD OF trigger would likely bomb due to Bug 1992006 (Assuming the use of ODBC, SQL*Loader, Oracle Forms etc.).
On the other hand, these issues seem to have been solved by mod_plsql, since I can upload a file directly into a documents table, and the mime_type, doc_size, and last_updated columns all get populated.
I would like to be able to populate a documents table using either mod_plsql or SQL*Loader and have the same results, but can't seem to figure out how to populate the above listed file attribute columns when I load from SQL*Loader.