I have a table with this type of value 20|10|5|8|19| (with separator)
I need to select rows, where first value (for example after explode), less than 20.
$arr = explode("|", "goal_times");
$first_goal_time = $arr[0];
But how to do this in Mysql query?
In general you shouldn't have multiple values with separator in the same column. In this case you can get away with SUBSTRING_INDEX()
SELECT *
FROM yourtable
WHERE
SUBSTRING_INDEX(yourcolumn,'|',1) < 20;
Related
I need to get maximum number from a part of the value that generally start with year followed by slash(/). So I need a maximum number after the slash(/) but year should be 2016
2016/422
2016/423
2016/469
2016/0470
2014/777
2015/123
2015/989
I tried this query
SELECT columname FROM tablename WHERE columname LIKE '2016/%' ORDER BY id DESC
the above query always giving '2016/469' as first record, how to get '2016/0470' as the maximum number?
any help will be much appreciated.
Thank you.
If columname follows that pattern YEAR/0000, you can use SUBSTRING function from MySQL to remove the part of the string you don't want.
SELECT value FROM (
SELECT CAST(SUBSTRING(columname, 0, 4) AS UNSIGNED) as year, CAST(SUBSTRING(columname FROM 6) AS UNSIGNED) as value FROM tablename
) total
ORDER BY year DESC, value DESC
LIMIT 1;
You need to split the string into 2 parts and evaluate them as numbers, instead of strings. The following formula will return the number after the / in the fieldname. All functions used below are described in the string functions section of the MySQL documentation. This way you can get the number after the / character, even if it is not year before the /, but sg else. The + 0 converts the string to a number, eliminating any leading 0.
select right(columnname, char_length(columnname)-locate('/',columnname)) + 0
from tablename
Just take the max() of the above expression to get the expected results.
UPDATE:
If you need the original number and the result has to be restricted to a specific year, then you need to join back the results to the original table:
select columnname
from tablename t1
inner join (select max(right(t.columnname, char_length(t.columnname)-locate('/',t.columnname)) + 0) as max_num
from tablename t
where left(t.columnname,4)='2016'
) t2
on right(t1.columnname, char_length(1t.columnname)-locate('/',t1.columnname)) + 0 = t2.max_num
where left(t1.columnname,4)='2016'
There are lots of suggestions given as answers already. But some of those seem overkill to me.
Seems like the only change needed to the OP query is the expression in the ORDER BY clause.
Instead of:
ORDER BY id
We just need to order by the numeric value following the slash. And there are several approaches, several expressions, that will get that from the example data.
Since the query already includes a condition columname LIKE '2016/%'
We can get the characters after the first five characters, and then convert that string to a numeric value by adding zero.
ORDER BY SUBSTRING(columname,6) + 0 DESC
If we only want to return one row, add
LIMIT 1
http://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_substring
If we only want to return the numeric value, we could use the same expression in the SELECT list, in addition columnname.
This isn't the only approach. There are lots of other approaches that will work, and don't use SUBSTRING.
Try like this:
SELECT
MAX(CAST(SUBSTRING(t.name,
LOCATE('/', t.name) + 1)
AS UNSIGNED)) AS max_value
FROM
tablename AS t;
You can try with this little uggly approach:
SELECT t.id, t2.secondNumber FROM table AS t
JOIN (SELECT id,
CONCAT(SUBSTRING(field,1,5),
if(SUBSTRING(SUBSTRING(field, 6),1,1)='0',
SUBSTRING(field, 6),
SUBSTRING(field,7)
)
) as secondNumber FROM table ) AS t2 ON t2.id=t.id
ORDER BY t2.secondNumber DESC
Would be valid only if the 0 (zeroes) before the second number (after the slash) are no more than 1.
Or if the year doesn`t matter you can try to order them only by the second number if it is ok:
SELECT t.id, t2.secondNumber FROM table AS t
JOIN (SELECT id,
if(SUBSTRING(SUBSTRING(field, 6),1,1)='0',
SUBSTRING(field, 6),
SUBSTRING(field,7)
) as secondNumber FROM table ) AS t2 ON t2.id=t.id
ORDER BY t2.secondNumber DESC
In a MySQL table i have a field, containing this value for a given record : "1908,2315,2316"
Here is my sql Query :
SELECT * FROM mytable WHERE 2316 IN (myfield)
I got 0 results!
I tried this :
SELECT * FROM mytable WHERE 2315 IN (myfield)
Still 0 results
And then i tried this :
SELECT * FROM mytable WHERE 1908 IN (myfield)
Surprisingly i obtained the record when searching with 1908! What should i do to also obtain the record when searching with 2315 and 2316 ? What am i missing ?
Thanks
You appear to be storing comma delimited values in a field. This is bad, bad, bad. You should be using a junction table, with one row per value.
But, sometimes you are stuck with data in a particular structure. If so, MySQL provides the find_in_set() functions.
SELECT *
FROM mytable
WHERE find_in_set(2316, myfield) > 0;
You can't use IN() over comma separated list of no.s its better to normalize your structure first for now you can use find_in_set to find results matching with comma separated string
SELECT * FROM mytable WHERE find_in_set('1908',myfield) > 0
This question has been asked and answered before, but I don't want to hunt for it; this question should be closed as a duplicate. But, to answer your question:
The commas in the string, the column value, are just characters. Those are part of the string. They aren't seen as "separators" between values in the SQL text. The way SQL sees it, the column contains a single value, not a "list" of values.
So, in your query, the IN (field) is equivalent to an equals comparison. It's equivalent to comparing to a string. For example:
... WHERE 2316 = '1908,2315,2316'
And those aren't equal, so the row isn't returned. The "surprisingly" finding of a match, in the case of:
... WHERE 1908 IN ('1908,2315,2316')
that's explained because that string is being evaluated in a numeric context. That is, the comparison returns true, because all of these also true:
... WHERE 1908 = '1908,2315,2316' + 0
... WHERE 1908 = '1908xyz' + 0
... WHERE 1908 = '1907qrs' + 1
(When evaluated in a numeric context, a string gets converted to numeric. It just happens that the string evaluates to a numeric value that equals the integer value it's being comparing to.)
You may be able to make use of the MySQL FIND_IN_SET function. For example:
... WHERE FIND_IN_SET(2316,'1908,2315,2316')
But, please seriously reconsider the design of storing comma separated list. I recommend Bill Karwin's "SQL Antipatterns" book...
http://www.amazon.com/SQL-Antipatterns-Programming-Pragmatic-Programmers/dp/1934356557
In mysql IN clause is utilized as
SELECT * FROM mytable WHERE column_name IN (set_of_values) ;
Mention column name instead of values
Please try
SELECT * FROM mytable WHERE LOCATE(CONCAT (',', 2316 ','), CONCAT (',',myfield,',' ) ) <>0
I have an events table with a field called breaks. This is populated with data in a comma separated format, i.e. 1,2,3 or 1 or 1,4,5 - the same format that MySQL's IN command uses.
I'd then like to run a query - on the slots table - to return all rows apart from those specified in events.breaks.
The query, theoretically, should be something like this:
SELECT
`slots`.`id` AS id,
RIGHT(`slots`.`time`, 8) AS `time`
FROM
`slots`, `event`
WHERE
`slots`.`id` NOT IN (`event`.`breaks`)
But that doesn't appear to work - if event.breaks is 4,5,7, the only row from the slots table that doesn't return is 4!
SQLFiddle here: http://sqlfiddle.com/#!2/913fe/1/0
You're passing a single field to the NOT IN () clause, not a subexpression. Think of it like this
(1, 2, 3)
is roughly the same as
SELECT 1
UNION
SELECT 2
UNION
SELECT 3;
as a subexpression. What you're doing instead is
('4,5,7')
which is roughly equivalent to
SELECT '4,5,7';
which in turn MySQL probably converted to a number for the comparison and the result is
NOT IN (4)
What you're actually trying to do isn't really supposed to be done like that. It'd be better if you added an AxB relation table so you can select several rows with the IDs you don't want.
Give this a try:
SELECT slots.id AS id, RIGHT(slots.time, 8) time
FROM slots, event
WHERE FIND_IN_SET(slots.id, event.breaks) = 0
This is how the FIND_IN_SET(str,strlist) function works:
Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings. A string list is a string composed of substrings separated by “,” characters. [...] Returns 0 if str is not in strlist or if strlist is the empty string.
Also note that IN (val1, val2, val3) is NOT the same as IN (val4) where val4 is a commma-separated string. The IN clause will compare by equality.
you may need a subselect to return the split string
... NOT IN (SELECT your_split_fnc(`event`.`breaks`) FROM `events`)
See answers here for a way to split strings in MySQL Can Mysql Split a column?
instr() MySQL function could be of help also
... INSTR(event.breaks,id) = 0
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_instr
I want to do a query like
select * from chr2;
but only have MySQL return the first tuple (or an arbitrary) tuple instead of all of them.
How do I do it?
Use the LIMIT clause:
SELECT * FROM chr2 LIMIT 1;
If you want an arbitrary row returned, you have to sort your rows by an random col like this (MySQL docu):
SELECT * FROM chr2
ORDER BY RAND()
LIMIT 1;
On large tables, however, you might run into performance problems with this, as there a random value has to be created for each row and the table has to be sorted according to this column.
Try this ::
select * from chr2 limit 1
I'm having trouble with one of my MySQL queries:
SELECT id,Portfolio,Agency,Program,Objective,billion1,value11_12,
Proportion1,billion,value12_13,Percentage,Difference,
Diff_Percent,PIT,TOS,Actual_PIT,Actual_TOS,SUM(billion),SUM(Percentage),
SUM(PIT),SUM(TOS),SUM(Actual_PIT),SUM(Actual_TOS)
FROM budget_table
GROUP BY 'sum(Billion)'
WITH ROLLUP
LIMIT 0,100
The query works but I can't get the limit to work with the rollup. You can see the results of the query at BudgetAus
It is totalling all results rather than the first 100 which is what I am now trying to achieve. I have also tried just using LIMIT 100 but can't get anything to work. I tried using EXPLAIN (for the first time) in MySQL on the database and it said that the query executed although I didn't see any results- but as I've never used it before I wasn't sure what to look for. I'm new to programming and use WAMP rather than a CLI.
I'm also not sure whether to start my limits from 0 or 1?
GROUP BY 'sum(Billion)'
This does not group by each distinct value of the Billion column. This groups by a single value, the constant string literal 'sum(Billion)'. So you'll get one group, because all rows have the same value when you use a constant string literal as your grouping expression.
Take the quotes off when you put an expression in the GROUP BY column.
Then you'll find that this is not a valid expression for grouping anyway.
SUM() operators can't be used in the GROUP BY expression, as SUM() is an aggregate operator, and hence makes no sense inside a GROUP BY
Therefore you should be using id, or some other field, for the GROUP BY.
The second parameter to LIMIT (the offset parameter) starts at 0, not 1.
My son (who is around here somewhere but I don't know his username) decided he wanted to solve this for me today and provided the following solution:
//Get the main result set
$result = mysql_query("SELECT * FROM budget_table ORDER BY Percentage DESC LIMIT 0,100 ");
//Build an array of the ids for the result set
$ids = array();
$rows = mysql_num_rows($result);
//Get id for each row and add to the ids
for($i = 0; $i < $rows; $i++) $ids[] = mysql_result($result, $i, "id");
//Join the ids into a string for use with IN()
$ids_str = implode(",", $ids);
//Get the sums for only the ids of the resultset above
$result2 = mysql_query("SELECT SUM(billion),SUM(Percentage),SUM(PIT),SUM(TOS),SUM(Actual_PIT),SUM(Actual_TOS) FROM budget_table WHERE id IN($ids_str)");