Re: [sqlite] how to add a new column quickly
Yes, it is fine. Thanks very much. 2007/5/7, Mohd Radzi Ibrahim <[EMAIL PROTECTED]>: How about this? update tablename set newcolname=(case rowid when 1 then 1 else 2 end); best regards, Radzi - Original Message - From: "Tomash Brechko" <[EMAIL PROTECTED]> To: <sqlite-users@sqlite.org> Sent: Saturday, May 05, 2007 8:09 PM Subject: Re: [sqlite] how to add a new column quickly > On Sat, May 05, 2007 at 19:30:59 +0800, ronggui wong wrote: >> Thanks. But there is no typo, what I want is a general solution. >> >> 2007/5/5, Tomash Brechko <[EMAIL PROTECTED]>: >> >On Sat, May 05, 2007 at 14:01:56 +0800, ronggui wong wrote: >> >> . update tablename set newcolname=1 where ROWID=1 >> >> . update tablename set newcolname=2 where ROWID=2 >> >> . update tablename set newcolname=2 where ROWID=3 > > If there is no correlation between newcolname and other columns that > can be expressed as a formula, but rather you want to set newcolname > to some known Func(ROWID), you may register this function with > sqlite3_create_function() (or its equivalent for your language > bindings), and then do a single statement > > UPDATE tablename SET newcolname = Func(ROWID); > > This will be faster then repeatedly searching for a row with a given > ROWID. > > > -- > Tomash Brechko > > - > To unsubscribe, send email to [EMAIL PROTECTED] > - > > - To unsubscribe, send email to [EMAIL PROTECTED] - - To unsubscribe, send email to [EMAIL PROTECTED] -
Re: [sqlite] how to add a new column quickly
How about this? update tablename set newcolname=(case rowid when 1 then 1 else 2 end); best regards, Radzi - Original Message - From: "Tomash Brechko" <[EMAIL PROTECTED]> To: <sqlite-users@sqlite.org> Sent: Saturday, May 05, 2007 8:09 PM Subject: Re: [sqlite] how to add a new column quickly On Sat, May 05, 2007 at 19:30:59 +0800, ronggui wong wrote: Thanks. But there is no typo, what I want is a general solution. 2007/5/5, Tomash Brechko <[EMAIL PROTECTED]>: >On Sat, May 05, 2007 at 14:01:56 +0800, ronggui wong wrote: >> . update tablename set newcolname=1 where ROWID=1 >> . update tablename set newcolname=2 where ROWID=2 >> . update tablename set newcolname=2 where ROWID=3 If there is no correlation between newcolname and other columns that can be expressed as a formula, but rather you want to set newcolname to some known Func(ROWID), you may register this function with sqlite3_create_function() (or its equivalent for your language bindings), and then do a single statement UPDATE tablename SET newcolname = Func(ROWID); This will be faster then repeatedly searching for a row with a given ROWID. -- Tomash Brechko - To unsubscribe, send email to [EMAIL PROTECTED] - - To unsubscribe, send email to [EMAIL PROTECTED] -
Re: [sqlite] how to add a new column quickly
On Sat, May 05, 2007 at 19:30:59 +0800, ronggui wong wrote: > Thanks. But there is no typo, what I want is a general solution. > > 2007/5/5, Tomash Brechko <[EMAIL PROTECTED]>: > >On Sat, May 05, 2007 at 14:01:56 +0800, ronggui wong wrote: > >> . update tablename set newcolname=1 where ROWID=1 > >> . update tablename set newcolname=2 where ROWID=2 > >> . update tablename set newcolname=2 where ROWID=3 If there is no correlation between newcolname and other columns that can be expressed as a formula, but rather you want to set newcolname to some known Func(ROWID), you may register this function with sqlite3_create_function() (or its equivalent for your language bindings), and then do a single statement UPDATE tablename SET newcolname = Func(ROWID); This will be faster then repeatedly searching for a row with a given ROWID. -- Tomash Brechko - To unsubscribe, send email to [EMAIL PROTECTED] -
Re: [sqlite] how to add a new column quickly
Thanks. But there is no typo, what I want is a general solution. 2007/5/5, Tomash Brechko <[EMAIL PROTECTED]>: On Sat, May 05, 2007 at 14:01:56 +0800, ronggui wong wrote: > . update tablename set newcolname=1 where ROWID=1 > . update tablename set newcolname=2 where ROWID=2 > . update tablename set newcolname=2 where ROWID=3 > . > > My question is: how to add the above task efificiently? Thanks! If there is a typo in the last line, and it should have been 'newcolname=3' (not 2), then your operation is effectively UPDATE tablename SET newcolname = ROWID; -- Tomash Brechko - To unsubscribe, send email to [EMAIL PROTECTED] - - To unsubscribe, send email to [EMAIL PROTECTED] -
Re: [sqlite] how to add a new column quickly
On Sat, May 05, 2007 at 14:01:56 +0800, ronggui wong wrote: > . update tablename set newcolname=1 where ROWID=1 > . update tablename set newcolname=2 where ROWID=2 > . update tablename set newcolname=2 where ROWID=3 > . > > My question is: how to add the above task efificiently? Thanks! If there is a typo in the last line, and it should have been 'newcolname=3' (not 2), then your operation is effectively UPDATE tablename SET newcolname = ROWID; -- Tomash Brechko - To unsubscribe, send email to [EMAIL PROTECTED] -
[sqlite] how to add a new column quickly
I would like to add a new column to an existing table. I use .alter table tablename add newcolname to add a new col, and use . update tablename set newcolname=1 where ROWID=1 . update tablename set newcolname=2 where ROWID=2 . update tablename set newcolname=2 where ROWID=3 . My question is: how to add the above task efificiently? Thanks! Ronggui Huang - To unsubscribe, send email to [EMAIL PROTECTED] -
