I am not much familiar with mysql here i am giving a portion of my query
(SELECT GROUP_CONCAT(Q.gender_id SEPARATOR ' , ') FROM path_career_gender_compatibility Q WHERE Q.data_entry_id = '1') AS career_gender_compatibility
here i am getting result as
1 , 2 , 3
but i want record like this
male,female,others
I dont know how to use a condition inside group_concat . I hope you all understand the problem any help is appreciable.
Probably you need CASE expression:
SELECT GROUP_CONCAT(case when Q.gender_id = 1 then 'male' when Q.gender_id = 2 then 'female' else 'other' end SEPARATOR ' , ')
FROM path_career_gender_compatibility Q
WHERE Q.data_entry_id = '1'
Related
How do I create an entirely new column in SQL while using CASE WHEN, GROUPING_ID(), and ROLLUP() syntax?
So far I have tried:
SELECT Country, ContactTitle, COUNT(ContactTitle) AS Count
,CASE(
WHEN
GROUPING_ID(Legend) = 0 THEN ' '
WHEN
GROUPING_ID(Legend) = 1 THEN 'SUBTOTAL(Country)')
GROUP BY ROLLUP(Country, ContactTitle)
FROM dbo.Customers
SELECT Country, ContactTitle, COUNT(ContactTitle) AS Count,
CASE
WHEN GROUPING_ID(Country,ContactTitle) = 0 THEN ''
WHEN GROUPING_ID(Country,ContactTitle) = 1 THEN CONCAT('Subtotal for ',Country)
END AS Legend
FROM dbo.Customers
GROUP BY ROLLUP(Country, ContactTitle);
A CASE needs an END.
And while testing, you could output the GROUPING_ID or GROUPING to understand what they return.
SELECT Country, ContactTitle, COUNT(*) AS Count,
(CASE
WHEN GROUPING_ID(Country, ContactTitle) = 1
THEN CONCAT('SUBTOTAL(',Country,')')
WHEN GROUPING(Country) = 1
THEN 'TOTAL'
ELSE ' '
END) AS Legend
FROM Customers
GROUP BY Country, ContactTitle WITH ROLLUP;
What am I doing wrong? It needs to display yes if more people are single than married and no if viceversa. I just want it to display yes or no only.
IF
select COUNT(StudMaritalStatus) from students WHERE StudMaritalStatus = "M"
<
select COUNT(StudMaritalStatus) from students WHERE StudMaritalStatus = "S"
Print 'Yes'
ELSE
Print 'No';
You want something like this:
select case when married >= single then 'M' else 'S' end
from
(
select sum(case when StudMaritalStatus = 'M' then 1 else 0 end) married
, sum (case when StudMaritalStatus = 'S' then 1 else 0 end) single
from students
) derivedTable
Tie breaking depends on your business requirements, which none of us know.
well considering that MySQL uses:
IF expression THEN
expression
ELSE
ENDIF;
you would be better of not doing it with a select statement
DECLARE married int, single int
SET married = select COUNT(StudMaritalStatus) from students WHERE StudMaritalStatus = 'M'
SET single = select COUNT(StudMaritalStatus) from students WHERE StudMaritalStatus = 'S'
IF married < single THEN
PRINT 'YES'
ELSE
PRINT 'NO'
END IF
In answer yes your syntax was wrong
https://dev.mysql.com/doc/refman/5.7/en/if.html
I have this query:
SELECT i.d, COUNT(id) AS dr, COUNT(id2) AS dn, SUM(eq) AS eq_sum, COUNT(thx) AS thx_count
FROM dsd
INNER JOIN
(
SELECT COUNT(id) AS d FROM ds
) i
Now I want to use WHERE only to column thx like WHERE thx="y" , so that it will count only all values with "y".
But If I just add WHERE at the end of the query it will affect other columns as well which I don't want to.
How to do this?
Then change your COUNT(thx) AS thx_count to below using CASE expression like
COUNT(CASE WHEN thx = 'y' THEN 1 ELSE 0 END) AS thx_count
(OR)
SUM(CASE WHEN thx = 'y' THEN 1 ELSE 0 END) AS thx_count
I've read a lot of the examples on self join, but they don't seem to cover the case where some fields are not in some rows.
For eg, I have a database with:
testId, testItem, testResult
And the rows:
1,test1,1
1,test2,0
1,test3,1
2,test1,0
2,test4,1
2,test5,1
I would like the output:
testItem,a.testId,b.testId,a.testResult,b.testResult
test1,1,2,1,0
test2,1,NULL,0,NULL
test3,1,NULL,1,NULL
test4,NULL,2,NULL,1
test5,NULL,2,NULL,1
Essentially, I want to compare each testItem (test1->test5) from two different testIds (1 and 2) and compare their testResult values, factoring in testIds that may not have the same test Items.
Given your exact requirement, you can try this:
select testItem
, max(case when testID = 1 then testID else null end) as testID1
, max(case when testID = 2 then testID else null end) as testID2
, max(case when testID = 1 then testResult else null end) as testResult1
, max(case when testID = 2 then testResult else null end) as testResult2
from mytable
where testID in (1,2)
group by testItem
This makes a lot of assumptions about your data, so take it with a grain of salt.
It looks like you want a FULL OUTER JOIN, which is not supported in MySQL. You can emulate this with a UNION of two queries: a LEFT JOIN query and RIGHT JOIN which throws out matching rows.
Something like this will return the specified resultset:
SELECT a.testItem
, a.testId AS `a.testId`
, b.testId AS `b.testId`
, a.testResult AS `a.testResult`
, b.testResult AS `b.testResult`
FROM mytable a
LEFT
JOIN mytable b
ON b.testItem = a.testItem
AND b.testId = 2
WHERE a.testId = 1
AND a.testItem IN ('test1','test2','test3','test4','test5')
UNION ALL
SELECT d.testItem
, c.testId
, d.testId
, c.testResult
, d.testResult
FROM mytable d
LEFT
JOIN mytable c
ON c.testItem = d.testItem
AND c.testId = 1
WHERE d.testId = 2
AND d.testItem IN ('test1','test2','test3','test4','test5')
AND c.testId IS NULL
ORDER
BY 1,2,4
(I included the predicates on testItem IN ('test1' thru 'test5') because you specified that as a requirement; those predicates could be removed if you want all values for testItem included.)
SQLFiddle Demo
select testItem,
group_concat(IFNULL(testId,'null') separator ', ') testIds,
group_concat(IFNULL(testResult, 'null') separator ', ') testResults
from table_name group by testItem;
I am trying to get the count of females and males in the gender field of a table.
Is there a way to get the count of each in one query?
Something like:
select * from table count(where gender = 'm') as total_males, count(where gender = 'f') as total_females;
or will it require two queries?
select count(*) from table where gender = 'm';
select count(*) from table where gender = 'f';
This is basically a PIVOT. MySQL does not have a pivot so you can use an aggregate function with a CASE statement to perform this:
select
sum(case when gender = 'm' then 1 else 0 end) Total_Male,
sum(case when gender = 'f' then 1 else 0 end) Total_Female
from yourtable
See SQL Fiddle with Demo
Or using COUNT:
select
count(case when gender = 'm' then 1 else null end) Total_Male,
count(case when gender = 'f' then 1 else null end) Total_Female
from yourtable;
See SQL Fiddle with Demo
Something like this will work:
SELECT SUM(IF(t.gender='m',1,0)) AS total_males
, SUM(IF(t.gender='f',1,0)) AS total_females
FROM mytable t
The "trick" here is that we are using a conditional test to return either a 0 or a 1 for each row, and then adding up the 0's and 1's. To make this a little more clear, I am using the SUM aggregate function rather than COUNT, although COUNT could be used just as easily, though we'd need to return a NULL in place of the zero.
SELECT COUNT(IF(t.gender='m',1,NULL)) AS total_males
, COUNT(IF(t.gender='f',1,NULL)) AS total_females
FROM mytable t
Consider that the two expressions in the SELECT list of this query:
SELECT COUNT(1)
, SUM(1)
FROM mytable t
Will return the same value.
If you want to avoid the MySQL IF function, this can also be done using the ANSI SQL CASE expression:
SELECT SUM( CASE WHEN t.gender = 'm' THEN 1 ELSE 0 END )) AS total_males
, SUM( CASE WHEN t.gender = 'f' THEN 1 ELSE 0 END )) AS total_females
FROM mytable t
select sum(case when gender='m' then 1 else null end) as total_males, sum(case when gender='f' then 1 else null end) as total_females from ...
Should work just fine!
If your only issue is to avoid two queries, you can always write two queries as subselects of one query.
Select (select 1 from dual) as one, (select 2 from dual) as two from dual
This would work for your scenario, too.