sql group by although there is not value - mysql

I have a table where exists 4 entries like this.
class_type
id type
1 A
2 B
3 M
4 T
and another table where these values are foreign key.
id number id_class_type
1 10 1
2 11 1
3 12 2
4 13 1
5 14 2
6 15 3
7 16 1
8 17 3
So what i want is count(*) and group by id_class_type but with all class_type (1,2,3,4) although there is not present the id 4.

if you want only the class tha match you can use inner join
select a.class_type, count(*)
from class_type a
inner join table2 b on a.id = b.id_class_type
group by a.class_type
otherwise you can use left join
select a.class_type, count(*)
from class_type a
left join table2 b on a.id = b.id_class_type
group by a.class_type

Related

how to choose value in 1 column that must have 2 values in another - sql?

table:
id lesson
11 11 A
8 11 B
4 11 A
4 11 A
2 11 A
6 11 A
5 11 A
13 11 A
11 11 B
the id 11 has both taught in classroom 11A, 11B. How to select the ids that have both values 11a,11b?
I tried this with no luck:
select id from table where lesson in '11A' and lesson in '11B'
because it gives empty table, because it can't be both 11a and b at the same time.
If it's exectly two values you can make an inner join
select a.id
from myTable a
inner join myTable b
on a.id = b.id
and a.lesson = '11 A' and b.lesson = '11 B'
for obtain the id with both the lesson
if could try using a subquery for the involved id and the count if the id have more then a result
select id
FROM (
select id
from my_table
where lesson in ('11A', '11b')
) t
group by id
having count(*) = 2

Joining the table creating a duplicate entry in laravel

I just want to merge the content of 2 tables and display it based on the ID.
Both the table has 3 entries.
Table a - Sampling order
Date Docname Products Quantity ID
1 A A 1 1
2 B B 2 1
3 C C 3 1
Table B - Representative locations
Date Area lat long ID
1 a 1 1 1
2 b 2 2 1
3 c 3 3 1
The output should generate like 3 rows with all the table A columns and B columns where ID = Specified ID
I need a output like this
Date Docname product Quantity Area lat long
1 A A 1 a 1 1
2 B B 2 b 2 2
3 C C 3 c 3 3
But its generating 9 rows (3*3) and duplicating the numbers of rows present in both the tables.
Its generating
Date Docname product Quantity Area lat long
1 A A 1 a 1 1
2 B B 2 b 2 2
3 C C 3 c 3 3
1 A A 1 a 1 1
2 B B 2 b 2 2
3 C C 3 c 3 3
1 A A 1 a 1 1
2 B B 2 b 2 2
3 C C 3 c 3 3
Combing number of rows in A * B - I just need only 3 rows with respect to ID.
Query -
$Report = DB::table('sampling_order')
->join('representativelocations','representativelocations.representativeid','=','sampling_order.representativeid')
->select('sampling_order.representativeid as representativeid',
'sampling_order.date as date',
'sampling_order.doctor_name as doctor_name',
'sampling_order.products as products',
'sampling_order.quantity as quantity',
'representativelocations.latitude as latitude',
'representativelocations.longitude as longitude',
'representativelocations.area as area')
->whereBetween('sampling_order.date', [$Datefrom, $Dateto])
->where('sampling_order.representativeid','=',$Representativeid)->get();
What I can see, all Id is '1' in two tables,
so it should be 3 * 3 = 9 rows in result.
I guess you may want this:
id product area-A area-B area-C
1____A____1____2_____3
1____B____2____3_____4
if so. you need to join three times.
SELECT * FROM A
LEFT JOIN (SELECT *, area AS area-A FROM B WHERE area = 'a' ) AS B ON B.id = A.id
LEFT JOIN (SELECT *, area AS area-B FROM B WHERE area = 'b' ) AS C ON C.id = A.id
LEFT JOIN (SELECT *, area AS area-C FROM B WHERE area = 'c' ) AS D ON D.id = A.id
Hope this is what you want.
Basing on the requirement, i think you should try joining on date not ID as below. This will return 3 rows as you are expecting.
select so.date,so.Docname,so.products,so.Quantity,rl.Area,rl.lat,rl.long from Sampling_order AS so
INNER JOIN Representative_locations as rl ON so.Date = rl.Date
WHERE so.ID = 1
Change table names and column names as needed.

MYSQL filter multiply row by two lists of id

I have results:
item_id subitem_id
----------------------
1 35
1 25
1 8
2 10
2 25
3 60
4 35
4 25
4 44
5 1
5 23
5 15
5 13
5 9
and I have two lists of subitem
(25,44,1)
(8,9)
how do I set the where clause in order to filter the result and return this
item_id subitem_id
----------------------
1 35
1 25 <-- first set
1 8 <-- second set
-----------------
5 1 <-- first set
5 23
5 15
5 13
5 9 <-- second set
because this item_id contain both subitem_id from two lists
SELECT
`item_id`
FROM table
WHERE `subitem_id` in (25,44,1)
AND `subitem_id` in (8,9)
Did not work, because in one time subitem_id have one id (not all list)
P.S.
This is a simple example, in reality we have more than 100k records with some join construction
http://sqlfiddle.com/#!9/71c28e5/3
SELECT t1.*
FROM (
SELECT DISTINCT(t1.item_id)
FROM t1
INNER JOIN t1 t2
ON t1.item_id = t2.item_id
AND t2.subitem_id in (8,9)
WHERE t1.subitem_id in (25,44,1)
) t
LEFT JOIN t1
ON t.item_id = t1.item_id
Another approach to avoid big number of executed records for mysql:
http://sqlfiddle.com/#!9/71c28e5/10
SELECT t1.*
FROM t1
WHERE item_id in (
SELECT DISTINCT(t1.item_id)
FROM t1
INNER JOIN t1 t2
ON t1.item_id = t2.item_id
AND t2.subitem_id in (25,44,1)
WHERE t1.subitem_id in (8,9)
)
SQL Fiddle
I think you're trying to make sure a item_ID has subcategories in 2 differen sets..
Select * from table A
where exists (Select 1 from table B where A.Item_Id = B.Item_ID and subitem_ID in (25,44,1))
and exists (Select 1 from table C where A.Item_Id = C.Item_ID and subitem_ID in (8,9))

How to fetch matched data from first table and unmatched from second table

I have 2 tables with same structure
eg. Table A and B with columns id,value.
Table A
ID VALUE
1 10
2 20
3 0
Table B
ID VALUE
1 24
2 26
3 0
4 40
5 50
expected output:
ID VALUE
1 10
2 20
3 0
4 40
5 50
as per output first three id is matched with table B so id(1,2,3) with value comes from table A and id(4,5) with value is not matched so it comes from table B.
You could use a right join on table b (or a left join on table a) and use a coalesce operator.
select b.id, coalesce(a.value, b.value)
from tablea a
right join tableb b on a.id = b.id
or
select b.id, coalesce(a.value, b.value)
from tableb b
left join tablea a on a.id = b.id
see SqlFiddle

Fetch DISTINCT records with JOIN of two tables

I have two tables:
builders
b_id fk_c_id
1 1
2 1
3 1
4 1
5 1
6 2
7 2
subbuilders
fk_b_id sb_id
1 2
1 3
1 4
2 5
6 7
and i want Distinct b_id which are not exist in subbuilders table and must have same fk_c_id
I create:
SELECT DISTINCT b.id FROM pms_builder_to_subbuilders bsb
LEFT JOIN pms_builders b ON b.id = bsb.sb_id WHERE b.fk_c_id = '1'
but it show Distinct records from subbuilders.
You can get the desired results with the following query:
SELECT DISTINCT b.b_id FROM builders b LEFT JOIN subbuilders sb ON sb.fk_b_id = b.b_id WHERE b.fk_c_id = '1' AND ISNULL(fk_b_id);
i think you want this query:
SELECT DISTINCT b_ID
FROM builders
WHERE b_ID NOT IN
(SELECT DISTINCT fk_b_id FROM subbuilders)
but it returns
b_ID
========
3
4
5
7
but i didn't understand your statement: must have same fk_c_id. What do you mean by that?
b_id = fk_c_id
if that's the case then there will be no rows returned because only record 1 has the same b_ID and fk_c_id but exists in table subbuilders