I am having column named rating in the mysql database table with multiple values from 1+,2+,................9+,10+,12+. when i am sorting this column with query
select * from tbl_app order by rating desc
I am getting 9+ as highest value, can any one tell me how to get 12+ as highest value
SELECT rating,SUBSTR(rating,1,LENGTH(rating)-1) FROM tbl_app ORDER BY CAST(SUBSTR(rating,1,LENGTH(rating)-1) as SIGNED) DESC;
if the last char is always a '+',the sql above will work.
what have you kept the datatype of the column rating ? If you have kept it varchar or text then this query will not work for sorting values as per descending order.
Probably the easiest thing to do in MySQL is cast those odd looking strings to numbers:
order by cast(rating as unsigned) desc
-- or less explicitly
order by rating + 0 desc
Both of those casts will stop trying to convert the string to a number when they hit the + so you'll get them sorted numerically.
Simply removing the plus signs from the strings will still leave you with strings and '10' < '2' is just as true for strings as '10+' < '2+'. That's actually your whole problem: you're storing numbers as decorated strings when you should be storing them as integers and adding the + decorations when you display them. You really should fix your schema to make sense instead of adding ugly hacks to work around your schema's strange ideas.
try this :
select convert(replace(rating,'+',' '),unsigned integer) as x from tab order by x desc
sql_fiddle_demo
Related
Struggling this the following sql statment.
The database is MySQL with score being DECIMAL(5,1)
Im looking to order by the average score within the column
...AVG(COALESCE(score,0)) AS scoreAvg ... ORDER BY scoreAvg DESC
but the results are not as expected, I have products with a high score below ones without a score (score is 0).
It lookings like score is being treated as a string, I have tried.
CAST(SCORE AS DECIMAL(5,1))
but with no luck.
Thank you for any help,
Regards
Try repeating the expression:
ORDER BY AVG(COALESCE(score, 0))
The first explanation that I think of is that scoreavg is already in a table and the ordering is using the column rather than the computed expression.
Your value might be in varchar(max)
So you want to convert the varchar to decimal or numeric and add
Order by avg(COALESCE(column name,0))
Or
Order by avg(coalesce(cast(column name as decimal (5,1)),0.0)
After stripping down my sql string, turns out my "image_path" column in TEXT format was causing the issue. Changed it to varchar(255).
I did'nt post it because I didnt think it was relevent.
anyway fixed now.
Must be a bug in MySQL
I've got a text field called source_recid. It stores half string half number like strings in it.
Example
shop.orders.32442
the syntax is DATABASENAME.TABLENAME.RECID
My goal is to scan this col and find out the biggest RECID ( the integer) in it.
So, in a case like this
shop.orders.32442
shop.orders.82000
shop.orders.34452
It would be the record whose source_recid is shop.orders.82000. Why? Cause 82000 happens to be the largest integer.
What SQL statement would get me that record?
One option to this is to create a new column ( the_ids ) and move all the integers in it and then run something like this
select source_recid from mytable
where source_recid like 'shop.orders.%'
order by the_ids DESC
LIMIT 1
Is there a way to pull this off without going thru this step?
First of all, unless all of your RECIDs are exactly five characters long forever and always, the select you put up won't work, becuase "shop.order.9" would come out as larger than "shop.order.10", which is wrong.
What I think we need to do here is extract the numeric part, cast it to an integer, and sort by that. Now, I don't have access to mySQL, so this may not be exactly right, but it should be close ...
SELECT
CAST(SUBSTRING_INDEX(RECID,'.',-1) AS INT) AS RecIdNumber
FROM
table
WHERE
RECID LIKE 'shop.order.%'
ORDER BY
RecIdNumber DESC
LIMIT
0, 1
This will take the part after the last dot, convert it to an INT, name it 'RecIdNumber', and sort by that.
I hope this helps.
SELECT CAST(SUBSTRING_INDEX(field,'.',-1) AS INT) AS RID
FROM yourtable
WHERE
RECID LIKE 'shop.order.%'
ORDER BY
RID DESC
I want to find the max value in a column.
Column values are,
E00004,
A00005,
B00011,
H-00001,
E2100112,
EFQ20098,
ESSF20003
I just want to sort the values by their number, Dont mind about the alphabets. It have to be like this, I'm using MYSQL
E2100112,
ESSF20003,
EFQ20098,
B00011,
A00005,
E00004,
H-00001
Assuming the last 5 digits are the number:
select columnName from tableName
order by convert(int, right(columnName, 5)) desc
As #IkeWalker stated, the number can have an arbitrary size.
For it, you'll have to use a while cycle to check the number.
Or, you can have a function do that for you!
Check this article!
I have a column of type varchar that stores many different numbers. Say for example there are 3 rows: 17.95, 199.95 and 139.95.How can i sort that field as numbers in mysql
Quickest, simplest? use * 1
select *
from tbl
order by number_as_char * 1
The other reasons for using * 1 are that it can
survive some horrendous mishaps with underflow (reduced decimal precision when choosing what to cast to)
works (and ignores) columns of purely non-numeric data
strips numeric portions of alphanumeric data, such as 123A, 124A, 125A
If you need to sort a char column containing text AND numbers then you can do this.
tbl contains: 2,10,a,c,d,b,4,3
select * from tbl order by number_as_char * 1 asc, number_as_char asc
expected output: 2,3,4,10,a,b,c,d
If you don't add the second order by argument only numbers will be sorted - text actually gets ignored.
Use a CAST or a CONVERT function.
This approach is helpful when sorting text as numbers:
SELECT `my_field`
FROM `my_table`
ORDER BY `my_field` + 0;
Found the solution on http://crodrigues.com/trick-mysql-order-string-as-number/.
Pad the string with leading zeroes:
ORDER BY LPAD(`column`,<max length of string>,"0")
If you really have to you can do this if your source data is compatible:
SELECT column FROM table ORDER BY CAST(column AS DECIMAL(10,2))
It's not going to be very fast for large data sets though. If you can you should change the schema to use DECIMAL in the first place though. Then it can be properly indexed for better performance.
I have a field number of type varchar. Even though it is of type varchar, it stores integer values with optional leading zeros. A sort orders them lexicographically ("42" comes before "9"). How can I order by numeric values ("9" to come before "42")?
Currently I use the query:
SELECT * FROM table ORDER BY number ASC
Try this
SELECT * FROM table_name ORDER BY CAST(field_name as SIGNED INTEGER) ASC
There are a few ways to do this:
Store them as numeric values rather than strings. You've already discounted that as you want to keep strings like 00100 intact with the leading zeros.
Order by the strings cast as numeric. This will work but be aware that it's a performance killer for decent sized databases. Per-row functions don't really scale well.
Add a third column which is the numeric equivalent of the string and index on that. Then use an insert/update trigger to ensure it's set correctly whenever the string column changes.
Since the vast majority of databases are read far more often than written, this third option above amortises the cost of the calculation (done at insert/update) over all selects. Your selects will be blindingly fast since they use the numeric column to order (and no per-row functions).
Your inserts and updates will be slower but that's the price you pay and, to be honest, it's well worth paying.
The use of the trigger maintains the ACID properties of the table since the two columns are kept in step. And it's a well-known idiom that you can usually trade off space for time in most performance optimisations.
We've used this "trick" in many situations, such as storing lower-cased versions of surnames alongside the originals (instead of using something like tolower), lengths of identifying strings to find all users with 7-character ones (instead of using len) and so on.
Keep in mind that it's okay to revert from third normal form for performance provided you understand (and mitigate) the consequences.
Actually i've found something interesting:
SELECT * FROM mytable ORDER BY LPAD(LOWER(mycol), 10,0) DESC
This allows you to order the field like:
1
2
3
10
A
A1
B2
10A
111
SELECT * FROM table ORDER BY number + 0
Trick I just learned. Add '+0' to the varchar field order clause:
SELECT * FROM table ORDER BY number+0 ASC
I now see this answer above. I am wondering if this is typecasting the field and an integer. I have not compared performance. Working great.
For a table with values like Er353, ER 280, ER 30, ER36
default sort will give
ER280
ER30
ER353
ER36
SELECT fieldname, SUBSTRING(fieldname, 1, 2) AS bcd,
CONVERT(SUBSTRING(fieldname, 3, 9), UNSIGNED INTEGER) AS num
FROM table_name
ORDER BY bcd, num;
the results will be in this order
ER30
ER36
ER280
ER353
you can get order by according to your requirement my using following sql query
SELECT * FROM mytable ORDER BY ABS(mycol)
given a column username containing VARCHAR's like these:
username1
username10
username100
one could do:
SELECT username,
CONVERT(REPLACE(username, 'username', ''), UNSIGNED INTEGER) AS N
FROM users u
WHERE username LIKE 'username%'
ORDER BY N;
it is not cheap, but does the job.
SELECT * FROM table ORDER BY number ASC
Should display what you want it to display.. looks like you're sorting it by id or number is not defined as integer at the moment.
MySQL ORDER BY Sorting alphanumeric on correct order
example:
SELECT `alphanumericCol` FROM `tableName` ORDER BY
SUBSTR(`alphanumericCol` FROM 1 FOR 1),
LPAD(lower(`alphanumericCol`), 10,0) ASC
output:
0
1
2
11
21
100
101
102
104
S-104A
S-105
S-107
S-111
Another option to keep numerics at a top, then order by alpha.
IF(name + 0, name + 0, 9999999), name
Rough and ready: order by 1*field_name