good morning.
Can anyone help me with the query, summarizing the total code in each table (Table 1 + table 2) as in table 3, thanks a lot.
Sorry, my english is not good
SELECT A.code, count(A.Date) as bang_1 , B.bang_2
FROM table_1 A
LEFT JOIN (SELECT code,count(*) as bang_2
FROM table_2
GROUP BY code) B ON A.code = B.code
GROUP BY A.code, B.bang_2
I think I understand what you are trying to do:
select codes.codename, t1.c as Table1, t2.c as Table2
from (
select codename from table1
union select codename from table2
) codes
left join (select codename, count(*) c from table1 group by codename) t1 on codes.codename = t1.codename
left join (select codename, count(*) c from table2 group by codename) t2 on codes.codename = t2.codename
group by codes.codename
order by codes.codename;
Example: https://dbfiddle.uk/?rdbms=mysql_5.5&fiddle=74d3bf30af406a2cdf65185a5fdcc564
Explanation
There are 2 subqueries t1 and t2. Both of them take a count of each code from each of the tables. The codes subquery combines codenames from both tables in case one table had more codes than the other.
Then, using the combined codenames connect with t1 and t2 and collect its respective counts.
Result
codename | Table1 | Table2
:------- | -----: | -----:
code1 | 2 | 1
code2 | 2 | 3
code3 | 1 | 1
Related
If I have two different tables in a SQL Server 2019 database as follows:
Table1
|id | name |
+-----+--------+
| 1 | rose |
| 2 | peter |
| 3 | ann |
| 4 | rose |
| 5 | ann |
Table2
| name2 |
+--------+
|rose |
|ann |
I would like to retrieve only the last tow ids from table1 (which in this case 4 and 5) that match name2 in table2. In other words, match happens only once on the last added names in table1, furthermore, the ids (4, 5) to be inserted in table2.
How to do that using SQL?
Thank you
You can use row_number()
select name,id from
(
select *, row_number() over(partition by t.name order by id desc) as rn
from table1 t join table2 t1 on t.name=t1.name2
)A where rn=1
Your question is vague, so there could be many answers here. My first thought is that you simply want an inner join. This will fetch ONLY the data that both tables share.
SELECT Table1.*
FROM Table1
INNER JOIN Table2 on Table1.name = Table2.name2
You seem to be describing:
select . . . -- whatever columns you want
from (select top (2) t1.*
from table1 t1
order by t1.id desc
) t1 join
table2 t2
on t2.name2 = t1.name;
This doesn't seem particularly useful for the data you have provided, but it does what you describe.
EDIT:
If you want only the most recent rows that match, use row_number():
select . . . -- whatever columns you want
from (select t1.*,
row_number() over (partition by name order by id desc) as seqnum
from table1 t1
) t1 join
table2 t2
on t2.name2 = t1.name and t1.seqnum = 1;
I'm trying to find a simple solution for my SQL Server problem.
I have two tables look like this:
table1
--id
-- data
table2
--id
--table1_id
--value
I have some records like this:
Table1
+-----------------------+
| id | data |
+-----------------------+
| 1 | ? |
+-----------------------+
| 2 | ? |
+-----------------------+
Table2
+-----------------------+
|id | table1_id | value |
+-----------------------+
| 1 | 1 | 'a' |
+-----------------------+
| 2 | 1 | 'b' |
+-----------------------+
| 3 | 2 | 'a' |
+-----------------------+
Now I want to get table1 with all it's additional values where the relation to table2 has 'a' AND 'b' as values.
So I would get the id 1 of table1.
Currently I have an query like this:
SELECT t1.[id], t1.[data]
FROM [table1] t1,
(SELECT [id]
FROM [table1] t1
JOIN [table2] t2 ON t1.[id] = t2.[table1_id] AND t2.[Value] IN('a', 'b')
GROUP BY t1[id]
HAVING COUNT(t2.[Value]) = 2) x
WHERE t1.id = x.id
Has anyone an idea on how to achieve my goal in a simpler way?
One way uses exists:
select t1.*
from table1 t1
where exists (select 1
from table2 t2
where t2.table1_id = t1.id and t2.value = 'a'
) and
exists (select 1
from table2 t2
where t2.table1_id = t1.id and t2.value = 'b'
);
This can take advantage of an index on table2(table1_id, value).
You could also write:
select t1.*
from table1 t1
where (select count(distinct t2.value)
from table2 t2
where t2.table1_id = t1.id and t2.value in ('a', 'b')
) = 2 ;
This would probably also have very good performance with the index, if table2 doesn't have duplicates.
SELECT T1.[id], T1.[data]
FROM table1 AS T1
JOIN table2 AS T2
ON T1.[id]=T2.[table1_id]
JOIN table2 AS T3
ON T1.[id]=T3.[table1_id]
WHERE
T2.[Value] ='a'
AND T3.[Value] = 'b'
As Gordon Linoff suggested, exists clause usage works as well and could be performance efficient depending on the data you are playing with.
you have to do several steps to solve the problem:
established which records are related to table 1 and table 2 and which of these are of value (A or B) and eliminate the repeated ones with the group by(InfoRelationate )
validate that only those related to a and b were allowed by means of a count in the table above (ValidateAYB)
see what data meets the condition of table1 and table 2 and joined table 1
this query meets the conditions
with InfoRelationate as
(
select Table2.table1_id,value
from Table2 inner join
Table1 on Table2.table1_id=Table1.id and Table2.value IN('a', 'b')
group by Table2.table1_id,value
),
ValidateAYB as
(
select InfoRelationate.table1_id
from InfoRelationate
group by InfoRelationate.table1_id
having count (1)=2
)
select InfoRelationate.table1_id,InfoRelationate.value
from InfoRelationate
inner join ValidateAYB on InfoRelationate.table1_id=ValidateAYB.table1_id
union all
select id,data
from Table1
Example code
I have to select every name from table1 where there's tuples that match every type from table2 without grouping or aggregate functions.
table1 table2
name|type type|info
a | 1 1 | .
a | 2 2 | ..
a | 3 3 | ...
b | 1
b | 2
b | 3
c | 2
From here, it should output
name|
a |
b |
edit:
ended up doing something like
SELECT distinct outside.name
FROM table1 outside
WHERE '' NOT IN
[ (SELECT *
FROM table1 t
WHERE t.name=outside.name)
RIGHT OUTER JOIN
table2 ]
Second select makes a table with empty values for names that don't have a type in table2. So if '' isn't in the second select that means it has a tuple for every type in table2. I think
Here is one method:
select t1.name
from table1 t1
where exists (select 1 from table2 t2 where t2.type = t1.type)
group by t1.name
having count(distinct t1.type) = (select count(distinct t2.type) from table2);
This filters t1 down to the matches in t2. It then counts the number that match.
This uses count(distinct), which allows duplicates in the respective tables. If there are no duplicates, then just use count().
I'm wondering if anybody can help me solve this question I got at a job interview. Let's say I have two tables like:
table1 table2
------------ -------------
id | name id | name
------------ -------------
1 | alpha 1 | alpha
3 | charlie 3 | charlie
4 | delta 5 | echo
8 | hotel 7 | golf
9 | india
The question was to write a SQL query that would return all the rows that are in either table1 or table2 but not both, i.e.:
result
------------
id | name
------------
4 | delta
5 | echo
7 | golf
8 | hotel
9 | india
I thought I could do something like a full outer join:
SELECT table1.*, table2.*
FROM table1 FULL OUTER JOIN table2
ON table1.id=table2.id
WHERE table1.id IS NULL or table2.id IS NULL
but that gives me a syntax error on SQL Fiddle (I don't think it supports the FULL OUTER JOIN syntax). Other than that, I can't even figure out a way to just concatenate the rows of the two tables, let alone filtering out rows that appear in both. Can somebody enlighten me and tell me how to do this? Thanks.
Well, you could use UNION instead of OUTER JOIN.
SELECT * FROM table1 t1
LEFT JOIN table2 t2 ON t1.id = t2.id
UNION
SELECT * FROM table1 t1
RIGHT JOIN table2 t2 ON t1.id = t2.id
Here's a little trick I know: not equals is the same as XOR, so you could have your WHERE clause something like this:
WHERE ( table1.id IS NULL ) != ( table2.id IS NULL )
select id,name--,COUNT(*)
from(
select id,name from table1
union all
select id,name from table2
) x
group by id,name
having COUNT(*)=1
I'm sure there are lots of solutions, but the first thing that comes to mind for me is to union all the two tables, then group by name, filter with a having clause on the count.
(
SELECT * FROM TABLE1
EXCEPT
SELECT * FROM TABLE2
)
UNION ALL
(
SELECT * FROM TABLE2
EXCEPT
SELECT * FROM TABLE1
)
This should work on most database servers
SELECT id, name
FROM table1
WHERE NOT EXISTS(SELECT NULL FROM table2 WHERE table1.id = table2.id AND table1.name = table2.name)
UNION ALL
SELECT id, name
FROM table2
WHERE NOT EXISTS(SELECT NULL FROM table1 WHERE table1.id = table2.id AND table1.name = table2.name)
I have 2 tables (perhaps they are badly built).
table1
id | word | user
1 | a | me
2 | b | dad
3 | c | mom
4 | d | sister
table2
id | word | user
1 | a | me
2 | b | dad
I want to show all rows from table1 excluding the rows from table2 which are equal to table1. In this case, the select must display row 3 and 4 from table.
Thanks.
Try this
Select * from Table1
Except
Select * from Table2
You did not specify what RDBMS but you can use NOT EXISTS in all databases:
select *
from table1 t1
where not exists (select *
from table2 t2
where t1.word = t2.word
and t1.user = t2.user
-- add other columns here for comparison including id)
See SQL Fiddle with Demo
Like so:
SELECT *
FROM Table1
WHERE id NOT IN(SELECT id FROM Table2);
Predicate NOT IN Fiddle Demo
Or: using a LEFT JOIN like so:
SELECT t1.*
FROM table1 t1
LEFT JOIN table2 t2 ON t1.id = t2.id
WHERE t2.id IS NULL;
LEFT JOIN Fiddle Demo
You can use EXCEPT (SQL-Server >= 2005)
SELECT id, word, user
FROM Table1
EXCEPT
SELECT id, word, user
FROM Table2;
DEMO
As you did not specify what flavour of SQL you are using, it is probably wise to steer clear of EXCEPTS and use standard ANSI SQL. So this is a case for using a left outer join.
SELECT t1.*
FROM table1 AS t1
LEFT OUTER JOIN table2 AS t2
ON t1.word = t2.word
AND t1.user = t2.user
WHERE t2.id IS NULL