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From: eric@wdl47.wdl.fac.com (Eric Kuhnen)
Newsgroups: comp.databases
Subject: Re: How to change each row in a table using SQL ?
Message-ID: <1990Nov5.191125.3008@wdl1.wdl.fac.com>
Date: 5 Nov 90 19:11:25 GMT
References: <1990Oct25.081639.14155@abblund.se> <1990Nov1.144502.18208@pds3>
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ravi@pds3 (Gorur R. Ravi) writes:

>	I would write a  small Pro*C program for problems like these. There
>might be an easier way to do this which I can't think of at this moment.
>You need to select ROWID in your SQL statement and get
>records using FETCH statement. Then update records in a while loop using
>ROWID in the WHERE clause. A partial code might look like this.

>	EXEC SQL DECLARE C1 CURSOR FOR SELECT ROWID FROM <TAB>;
>	EXEC SQL OPEN C1;
>	EXEC SQL WHENEVER NOT FOUND GOTO FINISH;
>	while(1)
>	{
>		EXEC SQL FETCH C1 INTO :rowid;
>		rowid.arr[rowid.len] = '\0';
>		
>		EXEC SQL UPDATE <TAB> SET ERR_FLD = <expr> WHERE
>		ROWID = :rowid;
>	}
>	FINISH: EXEC SQL CLOSE C1;

I think you'll find that the SQL "update" command will do everything that
you've outlined here, and with less confusion.  The solution is:

  update <tablename>
  set elapsed_time = elapsed_time - starting_time;

No cursors, rowids, fetch loops, muss, or fuss.  One simple command does it
all!  Plus, if you act now, we'll throw in this wonderful . . . .  Well, you
get the idea.

"Q"