I searched for a long and long list of oracle keywords and reserved words, but to no avail.
What does the part mean u''?
I am trying to convert Oracle database objects to PostgreSQL. I came across an expression Coalesce(some_field,u'')and this statement returns a syntax error in Postgres
Coalesce should return null if none of the parameters returns any nonzero value. But on execution, select u'' from dualI could see that the result is zero. I am not sure why they included it in the statement Coalesce(some_field,u'').
Is it possible to assume that the operator will work if the part u''does not exist at all in the instruction?
The guys I met completely deny the existence of such use in oracle u''googling was not fruitful because I did not know the concept.
Note: but when executed select Coalesce('sampleee text',u'') from dual
I get the following error:
ORA-12704: character set mismatch
12704. 00000 - "character set mismatch"
but on execution select Coalesce(u'sampleee text',u'') from dualI get a "sample file" as a result and errors ...
Therefore, I suspect this has something to do with the casting type for the Unicode character set. But I could be wrong.
A̶n̶y̶ ̶O̶r̶a̶c̶l̶e̶r̶s̶ / ̶T̶O̶M̶ (̶T̶h̶e̶O̶r̶a̶c̶l̶e̶M̶a̶s̶t̶e̶r̶s̶) ̶ ̶w̶h̶o̶ ̶c̶a̶̶̶̶̶̶̶a ̶
Update:
it seems that u is a prefix to indicate that the string includes Unicode character strings ... select chr(222),u'\00DE' from dual; refers to this
PostgreSQL, Postgres