disperse relational structure of MySQL table - mysql

I have a table that consists of
id (auto_increment)
number int (can contain values from 10 to 12)
myvalue (varchar)
What I want to do is disperse the relational structure of this table for report purpose. I.e , I´d like to have something like:
id (auto_increment)
number10 (containing myvalue WHERE number=10)
number11 (containing myvalue WHERE number=11)
number12 (containing myvalue WHERE number=12)
I know that I can get the respective results by
SELECT myvalue FROM mytable WHERE number = 10;
but I haven´t figured out how to write these three SELECT statements into one single table or view.
thx for any help in advance!

Something like this maybe?:
SELECT
id,
IF(number=10, myvalue, NULL) AS number10,
IF(number=11, myvalue, NULL) AS number11,
IF(number=12, myvalue, NULL) AS number12
FROM mytable

This might do what you need. You've not explained it very well though so it might not!
SELECT user,
MIN(CASE WHEN number = 10 then myvalue end) AS number10,
MIN(CASE WHEN number = 11 then myvalue end) AS number11,
MIN(CASE WHEN number = 12 then myvalue end) AS number12
FROM table
WHERE number IN (10,11,12)
GROUP BY user

I don't get the "id number10 number11 number12" stuff, but if you want to select the rows with the number field matching a set of values, you can just do:
SELECT * FROM mytable WHERE number IN (10, 11, 12);
Or, alternatively, you can select a number range:
SELECT * FROM mytable WHERE number >= 10 AND number <= 12;
Edit 2:
Vin-G's got it. I was way off.

Related

MySQL - Match certain IDs, but only those IDs

I have a table like so:
id_type id_option
"1" "1"
"1" "5"
"2" "1"
"2" "5"
"2" "8"
I am trying to write a query that given a list of option IDs finds the "type" that matches the list, but only those ID's
For example, if given 1 and 5 as options, it should return the type 1 but only the type 1 as the 8 required to match type 2 is not present.
I have tried the following:
SELECT *
FROM my_table
WHERE id_option IN (1, 5)
GROUP BY id_type
HAVING COUNT(DISTINCT id_option) = 2
This returns both "types" - I had hoped that the COUNT restriction of 2 would have helped but I now understand why it doesn't, but I can't think of a clever way to limit this.
I could just pull the first record as typically the types with less options are saved first but I don't think I can rely on this 100%
Thank you for your time
Here's a solution:
SELECT *
FROM my_table
GROUP BY id_type
HAVING SUM(id_option IN (1,5)) = COUNT(*)
It relies on a trick specific to MySQL: boolean true is literally the integer 1. So you can use SUM() to count the rows where a condition is true, but putting a boolean expression inside SUM().
For folks reading this who use other databases besides MySQL, you'd have to use an expression to convert the boolean condition to the integer 1:
HAVING SUM(CASE WHEN id_option IN (1,5) THEN 1 ELSE 0 END) = COUNT(*)
In this case, let all rows become part of the groups. That is, do not use a WHERE clause to restrict the query to rows where the id_option is 1 or 5. Then count the total rows in the group, and "count" (i.e. use the SUM() trick) the rows where the id_options is 1 or 5. Comparing these counts will be equal if there are no id_options values besides 1 or 5.
If you also want to make sure that both 1 and 5 are found, you need another condition:
SELECT *
FROM my_table
GROUP BY id_type
HAVING SUM(id_option IN (1,5)) = COUNT(*)
AND COUNT(DISTINCT CASE WHEN id_option IN (1,5) THEN id_option END) = 2
The CASE expression will return 1 or 5, or if there are any other values, those are converted to NULL. The COUNT() function ignores NULLs.
If you can pass the options as a sorted comma separated list string, then use GROUP_CONCAT():
SELECT id_type
FROM my_table
GROUP BY id_type
HAVING GROUP_CONCAT(id_option ORDER BY id_option) = '1,5'
If there are duplicate options for each type, use DISTINCT:
HAVING GROUP_CONCAT(DISTINCT id_option ORDER BY id_option) = '1,5'
While I can't comment yet, here's a tiny adjustment to Bill Karwin's last example (in the accepted solution):
SELECT *
FROM my_table
GROUP BY id_type
HAVING SUM(id_option IN (1,5)) = COUNT(*)
AND COUNT(DISTINCT id_option) = 2

convert all JSON columns into new table

I currently have a table structured like:
customer_id name phoneNumbers
1 Adam [{'type':'home','number':'687-5309'} , {'type':'cell','number':'123-4567'}]
2 Bill [{'type':'home','number':'987-6543'}]
With the phoneNumbers column set as a JSON column type.
For simplicity sake though I am wanting to covert all the JSON phone numbers into a new separate table.
Something like:
phone_id customer_id type number
1 1 home 687-5309
2 1 cell 123-4567
3 2 home 987-6543
It seems like it should be do-able with OPENJSON but so far I haven't had any luck in figuring out how to declare it correctly. Any help is appreciated.
USE recursive CTE with 1 and recurse upto json_length.
SELECT c.*, JSON_LENGTH(c.phoneNumbers) as json_length
from customers c;
then use concat to pass that element_id in Extract Query:
(json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.type.',1))), json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.number.',1))))
(json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.type.',2))), json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.number.',1))))
-
-
-
(json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.type.',json_length))), json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$.number.',json_length))))
You can do something like this:
SELECT id,
name,
JSON_UNQUOTE(JSON_EXTRACT(phone, CONCAT("$[", seq.i, "]", ".", "number"))) AS NUMBER,
JSON_UNQUOTE(JSON_EXTRACT(phone, CONCAT("$[", seq.i, "]", ".", "type"))) AS TYPE
FROM customer, (SELECT 0 AS I UNION ALL SELECT 1) AS seq
WHERE seq.i < json_length(phone)
The trick is (SELECT 0 as i union all SELECT 1), depends on your JSON array's length you may need to add more index. You can find out the max length by:
SELECT MAX(JSON_LENGTH(phone)) FROM customer;
Please change CTE defination syntax according to MySQL\Maria versions.
WITH RECURSIVE cte_recurse_json AS
(
SELECT customer_id, phone_numbers, 0 as recurse, JSON_LENGTH(c.phoneNumbers) as json_length,
json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$[',0,'].type'))) as type,
json_unquote(JSON_EXTRACT(phoneNumbers, CONCAT('$[',0,'].number'))) as number
FROM table
UNION ALL
SELECT t.customer_id, t.phone_numbers, ct.recurse + 1 as recurse, t.json_length,
json_unquote(JSON_EXTRACT(ct.phoneNumbers, CONCAT('$[',ct.recurse,'].type'))) as type,
json_unquote(JSON_EXTRACT(ct.phoneNumbers, CONCAT('$[',ct.recurse,'].number'))) as number
FROM TABLE t
INNER JOIN cte_recurse_json ct ON t.customer_id = ct.customer_id
WHERE ct.recurse < json_length
)
SELECT customer_id, type, number FROM cte_recurse_json;

mysql count distinct value

I have trouble wondering how do I count distinct value. using if on the select column
I have SQLFIDDLE here
http://sqlfiddle.com/#!2/6bfb9/3
Records shows:
create table team_record (
id tinyint,
project_id int,
position varchar(45)
);
insert into team_record values
(1,1, 'Junior1'),
(2,1, 'Junior1'),
(3,1, 'Junior2'),
(4,1, 'Junior3'),
(5,1, 'Senior1'),
(6,1, 'Senior1'),
(8,1, 'Senior2'),
(9,1, 'Senior2'),
(10,1,'Senior3'),
(11,1, 'Senior3'),
(12,1, 'Senior3')
I need to count all distinct value, between Junior and Senior column.
all same value would count as 1.
I need to see result something like this.
PROJECT_ID SENIOR_TOTAL JUNIOR_TOTAL
1 3 3
mysql query is this. but this is not a query to get the result above.
SELECT
`team_record`.`project_id`,
`position`,
SUM(IF(position LIKE 'Senior%',
1,
0)) AS `Senior_Total`,
SUM(IF(position LIKE 'Junior%',
1,
0)) AS `Junior_Total`
FROM
(`team_record`)
WHERE
project_id = '1'
GROUP BY `team_record`.`project_id`
maybe you could help me fix my query above to get the result I need.
thanks
I think you want this:
SELECT
project_id,
COUNT(DISTINCT CASE when position LIKE 'Senior%' THEN position END) Senior_Total,
COUNT(DISTINCT CASE when position LIKE 'Junior%' THEN position END) Junior_Total
FROM team_record
WHERE project_id = 1
GROUP BY project_id
The CASE will return a null if the WHEN is false (ie ELSE NULL is the default, which I omitted for brevity), and nulls aren't counted in DISTINCT.
Also, unnecessary back ticks, brackets and qualification removed.

mySQL count occurances of value on multiple fields. How?

I have a table with 5 fields. Each field can store a number from 1 - 59.
Similar to countif in Excel, how do I count the number of times a number from 1 - 59 shows up in all 5 fields?
Here's an example for the count of occurances for the number 1 in all five fields:
SELECT SUM(pick_1 = 1 OR pick_2 = 1 OR pick_3 = 1 OR pick_4 = 1 OR pick_5 = 1) AS total_count_1
FROM tbldraw
Hopefully I made sense.
There was an answer here that had a solution. I think this is just a variation.
Step1: Create a numbers table (1 field, called id, 59 records (values 1 -59))
Step2:
SELECT numbers_table.number as number
, COUNT(tbldraw.pk_record)
FROM numbers_table
LEFT JOIN tbldraw
ON numbers_table.number = tbldraw.pick_1
OR numbers_table.number = tbldraw.pick_2
OR numbers_table.number = tbldraw.pick_3
OR numbers_table.number = tbldraw.pick_4
OR numbers_table.number = tbldraw.pick_5
GROUP BY number
ORDER BY number
How about a two step process? Assuming a table called summary_table ( int id, int ttl), for each number you care about...
insert into summary_table values (1,
(select count(*)
from table
where field1 = 1 or field2 = 1 or field3 = 1 or field4 = 1 or field5 = 1))
do that 59 times, once for each value. You can use a loop in most cases. Then you can select from the summary_table
select *
from summary_table
order by id
That will do it. I leave the coversion of this SQL into a stored procedure for those that know what database is in use.
The ALL() function, which returns true if the preceding operator is true for all parameters, makes the query particularly elegant and succinct.
To find the count a particular number (eg 3):
select count(*)
from tbldraw
where 3 = all (pick_1, pick_2, pick_3, pick_4, pick_5)
To find the count of all such numbers:
select pick_1, count(*)
from tbldraw
where pick_1 = all (pick_2, pick_3, pick_4, pick_5)
group by pick_1

Is there a way to GROUP BY using one column, but a set of values it could equal for a given group?

Is there a way to GROUP BY using one column, but a set of values it could equal for a given group?
For instance, say I have the records:
id = 1, quantity = 40, type = 1
id = 2, quantity = 50, type = 2
id = 3, quantity = 20, type = 1
id = 4, quantity = 30, type = 3
id = 5, quantity = 60, type = 3
And I would like to group types 1 and 2 together, and group type 3s by themselves. Is there a simple way to do this in MySQL, or am I better off doing this after I get the results?
Sure, you can create a custom group using a CASE statement:
select case when id in (1,2)
then '1,2'
else id
end as custom_id_group
...
group by case when id in (1,2)
then '1,2'
else id
end
Edit:
Using the result of a CASE statement, via alias, in the GROUP BY clause isn't universally supported across RDBMSs, but more-recent versions of MySQL (>=5) will support it.
I suggest use two query and union the result
Maybe if you use something like "select *, if (type=1 or type=2, 'bigtype', type) as group_by_clause group by group_by_clause.
I didn't try it
You can do like this:
select count(*), if(type in (1, 2), 12, type) t from table group by t