Greater Than and Less than MySql query failing with decimal field - mysql

Question

I have a database which has 3 columns:
user_id | lat | lon
1 |-1.403976 | 53.428692
2 |-1.353276 | 55.224692
etc etc
Both lat and lon are set as decimal fields. I'm running a query similar to this but it isn't filtering based on being greater than and less than the given lat/lon numbers:
SELECT * FROM `table` WHERE `lat` < '-1.399999' AND 'lat' > '-1.300000'
AND 'lon' < '55.555555' AND > '53.000000'
This query just returns every row in the table and I don't know why? Is it something to do with the fields being set as decimals?
I hope someone can help - i know its probably a simple answer if you know it.
As per comment - here's the create table:
CREATE TABLE IF NOT EXISTS `members` (
`user_id` int(10) NOT NULL AUTO_INCREMENT,
`lat` decimal(8,6) NOT NULL,
`lon` decimal(8,6) NOT NULL,
UNIQUE KEY `user_id` (`user_id`),
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=136 ;

Answer 1

the problem is you are wrapping column names with single quotes forcing decimal values to compare against string literals. Column names as well as tables name are identifiers not string literals so they shouldn't be wrap with single quotes.
AND `lat` > '-1.300000'
AND `lon` BETWEEN '55.555555' AND '53.000000' -- use between here

Answer 2

As #JW suggests, you're mixing up backticks (`) and single quotes ('). Use backticks around database table and column names, but quotes around data values.
Also, the second half of your query doesn't match the first half. You have
`lat` < '-1.399999' AND 'lat' > '-1.300000'
'lon' < '55.555555' AND > '53.000000'
But it should be
`lat` < '-1.399999' AND `lat` > '-1.300000'
`lon` < '55.555555' AND `lon` > '53.000000'
So you're missing the column name in the fourth statement there.
Or, as #JW says, use BETWEEN which makes it easier to read too!
SELECT * FROM `table` WHERE `lat` BETWEEN '-1.399999' AND '-1.300000' AND `lon` BETWEEN '55.555555' AND '53.000000';

Answer 3

Example:
Query the sum of Northern Latitudes (LAT_N) from STATION having values greater than 38.7880 and less than 137.2345. Truncate your answer to 4 decimal places.
SELECT TRUNCATE(SUM(LAT_N),4)
FROM STATION
WHERE LAT_N > 38.7880 and LAT_N < 137.2345;

Answer 4

The question is pretty straight forward and your developed query need to use one of the attribute: LAT_N.
The lowest and highest value for LAT_N is given in the question. BETWEEN function will help you get the value between the highest and lowest value of LAT_N and ROUND function will get us value rounded to desired decimals(4 in this case).
My query will be as follows:
SELECT ROUND(SUM(LAT_N),4)
FROM STATION
WHERE LAT_N BETWEEN 38.7880 AND 137.2345;