> -----Original Message----- > From: P Kishor [mailto:[EMAIL PROTECTED] > Sent: Thursday, January 31, 2008 3:35 PM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] Using LIKE to check the first digits? > > On 1/31/08, Gilles <[EMAIL PROTECTED]> wrote: > > Hello > > > > I'm no SQL guru, and need to look up phone numbers in a SQLite database > > that start with certain digits. Some customers use > > http://en.wikipedia.org/wiki/Direct_Inward_Dialing, which means that the > > first part is common to all the numbers assigned to this customer, so I > > don't need to enter every single one of them, and just assign the > prefix, > > eg. "123" matches "1230001", "1230002", etc. > > > > Should I use the LIKE command for this? Does someone have an example to > do > > this? > > > > WHERE col LIKE '123%' > > or WHERE substr(col,1, 3) = '123'
One note: The optimizer has a decent chance of using an index for LIKE '123%' but I'd be surprised (and impressed) if it looks inside function calls such as substr for opportunities to use indexes. -- James ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
