sql query question - mysql

I have tables
table 1
id text
1 A
1 B
2 C
table 2
id text
1 x
1 f
2 y
2 z
I want to join them this way
1 A x
1 B f
2 C y
2 z
In other words i want to see all texts from table1 and table2 grouped by id, with no repeats.
Any ideas?
Update: as they say in comments, the logic is not clear, I'll try to explain.
I have current values in table_1 and deleted values in table_2.
Customer wants to see current values and deleted values in one table grouped by some id.

Simple solution to get something close to what you're looking for
SELECT t1.id, t1.text, t2.text
FROM tbl_1 t1
INNER JOIN tbl_2 t2
ON t1.id = t2.id
this will create output
1 A x
1 B x
2 C y
2 C z
Only different is now that the duplicated texts x and C should somehow removed.
Update
precondition: duplicates per id are either in tbl_1 or tbl_2 not both !
Joining a grouped select in addition to above simple solution will allow to create kind of "CASE-Filters" to get your desired output.
SELECT
t1.id,
CASE
WHEN t2.text = txt_i2 THEN t1.text
END AS txt_t1,
CASE
WHEN t1.text = txt_i1 THEN t2.text
END AS txt_t2
FROM (
SELECT
i1.id,
i1.text AS txt_i1,
i2.text AS txt_i2
FROM tbl_1 i1
INNER JOIN tbl_2 i2
ON i1.id = i2.id
GROUP BY id
) i
INNER JOIN tbl_1 t1
ON i.id = t1.id
INNER JOIN tbl_2 t2
ON t1.id = t2.id
You should create a view of the tbl_1-tbl_2-join to get more readable SQL:
CREATE OR REPLACE VIEW V_tbl_1_2 AS (
SELECT
t1.id,
t1.text AS txt_1,
t2.text AS txt_2
FROM tbl_1 t1
INNER JOIN tbl_2 t2
ON t1.id = t2.id
)
;
SELECT
t.id,
CASE
WHEN t.txt_2 = i.txt_2 THEN t.txt_1
END AS txt_t1,
CASE
WHEN t.txt_1 = i.txt_1 THEN t.txt_2
END AS txt_t2
FROM V_tbl_1_2 t
INNER JOIN (
SELECT *
FROM V_tbl_1_2
GROUP BY id
) i ON t.id = i.id
;

USE MYSQL VIEW OR JOIN

This works if you can have no more than two items per id in either table and if neither one has complete duplicates. (And I must also add that this can only work if MySQL is able to swallow this monster and not choke with it.)
SELECT
COALESCE (t1.id, t2.id) AS id,
t1.text AS text1,
t2.text AS text2
FROM (
SELECT
t.id,
t.text,
CASE t.text WHEN m.text THEN 1 ELSE 2 END AS rowid
FROM table_1 t
INNER JOIN (
SELECT id, MIN(text) AS text
FROM table_1
GROUP BY id
) m ON t.id = m.id
) t1
FULL JOIN (
SELECT
t.id,
t.text,
CASE t.text WHEN m.text THEN 1 ELSE 2 END AS rowid
FROM table_2 t
INNER JOIN (
SELECT id, MIN(text) AS text
FROM table_2
GROUP BY id
) m ON t.id = m.id
) t2
ON t1.id = t2.id AND t1.rowid = t2.rowid
ORDER BY COALESCE (t1.id, t2.id), COALESCE (t1.rowid, t2.rowid)

Related

Select from 1 table sum from 2 but 1 table has a AND condition

Thanks for assisting with the previous query (SQL Query that selects a column in table 1 and uses that to select sum in table 2) of SUM from 2 tables, I now have a additional Condition for 1 of the tables. I would like to add WHERE Group1 = 1 AND IN/OUT = 'OUT'
I have 3 tables,
Names ,Groups
Names ,Payments
Names ,Payments and IN/OUT
I want to only SUM the OUT Payments in Table 3, I am getting total payments only So FAR is have:
SELECT t1.name1, SUM(t2.sale2),SUM(t3.sale3)
FROM table1 t1 JOIN table2 t2 ON t1.name1 = t2.name2
JOIN table3 t3 ON t1.name1 = t3.name3
WHERE group1 = 1
GROUP BY t1.name1
i would also like to add a zero if there is no data to sum instead of removing the whole record, Currently if a name has no payments in Table 3 but has payments in table 2 it deletes the record.
Please check the query below =>
To Get OutPayment group by Name
SELECT t1.Names,SUM(t3.Payments) As OutPayment
FROM TABLE3 as t3
INNER JOIN TABLE1 as t1 ON t1.Names = t3.Names
INNER JOIN TABLE2 as t2 ON t1.Names = t2.Names
WHERE t1.GroupID = 1 AND t3.INOROUT=2 --INOROUT =2 is OUT and 1 is IN
GROUP BY t1.Names;
To Get TotalOutPayment
SELECT SUM(t3.Payments) As TotalOutPayment
FROM TABLE3 as t3
INNER JOIN TABLE1 as t1 ON t1.Names = t3.Names
INNER JOIN TABLE2 as t2 ON t1.Names = t2.Names
WHERE t1.GroupID = 1 AND t3.INOROUT=2; --INOROUT =2 is OUT and 1 is IN
Note: Code is in DBFiddle too Check the Demo Query Link

How to use 'group by' while having a sub query in MySQL?

I have the following query:
SELECT c.text1, sum(c.num1), sum(c.num2), sum(c.num3),
(SELECT count(id) FROM table2 WHERE type = 1 AND txt = c.text1 AND spec_id = c.sp_id)
FROM table1 as c
WHERE c.type = 1
GROUP BY c.text1, c.sp_id
Is there a workaround to loose the c.sp_id from the GroupBy clause somehow? I know that if I remove it MySQL will return an error.
Or is there a way to group the results of this query by c.text1 only?
If I understand the problem correctly, you need to do two separate aggregations. This is one version of the query:
SELECT c.text1, c.sum1, c.sum2, c.sum3, t2.cnt
FROM (SELECT c.text1, sum(c.num1) as sum1, sum(c.num2) as cum2, sum(c.num3) as sum3
FROM table1 c
GROUP BY c.text1
) c LEFT JOIN
(SELECT txt, count(*) as cnt
FROM table2 t2
WHERE t2.type = 1 AND
EXISTS (SELECT 1
FROM table1 c2
WHERE t.txt = c2.txt AND c2.type = 1 AND
t.spec_id = c2.sp_id
)
) t2
ON t2.txt = c.text1
WHERE c.type = 1;

SQL: full outer join (ambitious column name)

I have two table, t1 and t2.
-- t1
id name address
1 Tim A
2 Marta B
-- t2
id name address
1 Tim A
3 Katarina C
If I do t1 full outer join with t2
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION ALL
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
However, the result has ambitious id, name, address.
How do I rename this so that I don't have duplicate column name?
Attempt:
SELECT name, address FROM
(SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION ALL
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id) as derived_table;
return: ERROR- duplicate column name "name".
Ditch the * in the SELECT list.
Specify the list of expressions to be returned. And qualify all column references with either the table name, or preferably, a shorter table alias.
And assign an alias to the expression and that will be the name of the column in the resultset.
Also, the query shown is not equivalent to a FULL OUTER JOIN.
If the goal is return all rows from t1, and to also return rows from t2 where a matching row doesn't exist in t1, I'd do something like this...
SELECT t.id AS t_id
, t.name AS t_name
, t.addr AS t_addr
FROM t1 t
UNION ALL
SELECT s.id
, s.name
, s.addr
FROM t2 s
LEFT
JOIN t1 r
ON r.id = s.id
WHERE r.id IS NULL
Try fully qualifying it like
SELECT t1.id, t1.name, t1.address FROM t1

select from 2 tables with for statement in sql

i have 2 table and want to select data from them
table 1 :
id
name
table 2
id
name
table1.id
and i want a query to make this resualt:
table1.id
table1.name
count(table2.id)
this is simple and solved by this way :
SELECT
c.id as corridor_id,
c.name as corridor_name,
(SELECT COUNT( r.id ) FROM rooms AS r WHERE r.corridorid = c.id ) as room_count
FROM corridors AS c
now if i add another table like this :
table3
id
name
table2.id
and want a query like this :
table1.id
table1.name
count(table2.id)
count(table3.id)
idk how can i do such as this query, but if there is a way i'll be happy to find it, many tnx
You'll want to join them all together, and then Group them along these lines:
SELECT
t1.Id,
t1.Name,
Count(t2.Id) AS T2Count,
Count(t3.Id) AS T3Count
FROM table1 t1
JOIN table2 t2
ON t1.Id = t2.table1_id
JOIN table3 t3
ON t2.id = t3.table2_id
GROUP BY t1.Id, t1.Name
You don't need nested SELECT statement here. You can do it by grouping and to avoid double-counting you would want DISTINCT keyword:
SELECT
c.id as corridor_id,
c.name as corridor_name,
COUNT(DISTINCT r1.id),
COUNT(DISTINCT r2.id)
FROM
corridors c
JOIN rooms r ON r.corridorid = c.id
JOIN rooms2 r2 ON r2.corridorid = c.id
GROUP BY c.id
If you want to properly treat missing values (0 counts) you can also do this:
SELECT
c.id as corridor_id,
c.name as corridor_name,
IFNULL(COUNT(DISTINCT r1.id), 0),
IFNULL(COUNT(DISTINCT r2.id), 0)
FROM
corridors c
LEFT JOIN rooms r ON r.corridorid = c.id
LEFT JOIN rooms2 r2 ON r2.corridorid = c.id
GROUP BY c.id

simple mysql query count fails

SELECT
count(t1.id) AS c1
FROM
table2
LEFT JOIN table1 AS t1 ON (t1.uid = table2.uid)
WHERE
table2.mode = 'ls'
GROUP BY
t1.id
c1 = 6 -> CORRECT!
SELECT
count(t2.id) AS c2
FROM
table2
LEFT JOIN table1 AS t2 ON (t2.pid = table2.id)
WHERE
table2.mode = 'ls'
GROUP BY
t1.id
c2 = 1 -> CORRECT!
SELECT
count(t1.id) AS c1,
count(t2.id) AS c2
FROM
table2
LEFT JOIN table1 AS t1 ON (t1.uid = table2.uid)
LEFT JOIN table1 AS t2 ON (t2.pid = table2.id)
WHERE
table2.mode = 'ls'
GROUP BY
t1.id
c1 = 6 -> CORRECT!
c2 = 6 -> WRONG!
How do I request both counts in one query, without getting wrong results?
I need to count two different requests at the same table (table1).
so, I'm using an alias for both request. (t1). Each alias-request is working fine alone. If I use both in the same query, i got wrong results.
count() will get you the number of records that are returned by your query. Since if you removed the counts and replaced it with * you would have 6 rows both of those counts are giving you 6.
Is there any reason why you cant use two sub selects and return the result of each of those?
So:
SELECT subQ1.c1, subQ2.c2 FROM
(SELECT count(t1.id) AS c1 FROM table2
LEFT JOIN table1 AS t1 ON (t1.uid = table2.uid)
WHERE table2.mode = 'ls') as subQ1,
(SELECT count(t2.id) AS c2 FROM table2
LEFT JOIN table1 AS t2 ON (t2.pid = table2.id)
WHERE table2.mode = 'ls') as SubQ2;
I believe your problem on the full query is your group by function. You are grouping by t.id, thus a1.id will have a different count based on how many rows you have.
What I mean by this is if there are 6 rows in table t, then count is going to return 6 for table t; but also since there looks to be a 1 to 1 relation on table a, there are 6 matching rows in table a to the 6 matching rows in table t. such that
t.id = a.id
1 = 1
2= 2 ...etc.
Thus your count is returning rows versus the count you believe you should have? I believe sum function is what you want to use here.
You could try this...but I'm not really sure what you're trying to do.
SELECT (...)
count(CASE WHEN t1.uid = t3.uid THEN t1.id ELSE NULL END) AS CBanz,
count(CASE WHEN ta1.pid = t3.id THEN a1.id ELSE NULL END) AS CBanz1
FROM
t0
LEFT JOIN (...)
LEFT JOIN t1 ON (t1.uid = t3.uid)
LEFT JOIN t1 AS a1 ON (a1.pid = t3.id)
WHERE (...)