RE: Lat/Long storage?
NUMBER(8,5). You'll need around 5 digits after the decimal point. (Think GPS accuracy == 10 meters for high-grade, 100 m for dumbed-down civilian use. At the equator, that's 0.9 or 0.0009 degrees respectively. At higher latitudes, that'd be correspondingly less.) If you value accuracy, DON'T USE FLOAT. Float has only 6-7 digits of accuracy, which, if you take out the 3 digits before the ., leave you with only 3 decimal places after (== roughly 1 km - too rough). Use Double (which would be 8 characters), or use number (8,5) or number (7,4), which are approximately the same size. The latter are easier to work with for display purposes, the former for computation purposes. Take your pick. If you use NUMBER(#,#), you should make sure that internally, you convert them directly to and from double to preserve the accuracy of the numbers. -Original Message- From: Nelson Goforth [mailto:[EMAIL PROTECTED]] Sent: Monday, June 25, 2001 2:03 PM To: [EMAIL PROTECTED] Subject: Lat/Long storage? I need to store latitude and longitude in a MySQL table. It needs to allow human entry. Do you have a preferred storage technique for these numbers? Nelson Goforth --
RE: Lat/Long storage?
mysql desc zipcodes; +---+--+--+-+-++ | Field | Type | Null | Key | Default | Extra | +---+--+--+-+-++ | id| int(10) unsigned | | PRI | NULL| auto_increment | | zipcode | char(5) | | MUL | 0 || | latitude | double(6,4) | YES | | NULL|| | longitude | double(6,4) | YES | | NULL|| +---+--+--+-+-++ works ok for me.. -Original Message- From: Nelson Goforth [mailto:[EMAIL PROTECTED]] Sent: Monday, June 25, 2001 4:03 PM To: [EMAIL PROTECTED] Subject: Lat/Long storage? I need to store latitude and longitude in a MySQL table. It needs to allow human entry. Do you have a preferred storage technique for these numbers? Nelson Goforth -- - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
