I have two tables, lets say table1 and table2.
table1 || table2
--------||-------------
col1 || col1 | col2
--------||------|------
a || a | 4
b || a | 2
c || a | 5
d || b | 1
|| b | 3
|| d | 6
With SELECT table1.col1, table2.col2 FROM table1 LEFT OUTER JOIN table2 ON table1.col1 = table2.col1 I get following:
table1.col1 | table2.col2
-------------|-------------
a | 4
a | 2
a | 5
b | 1
b | 3
c | NULL
d | 6
How is it possible to achieve this (only get the minimum of table2.col2 so that there's no entry of table1.col1 more than once):
table1.col1 | table2.col2
-------------|-------------
a | 2
b | 1
c | NULL
d | 6
Or is it a wrong approach?
You need to use MIN:
SELECT
t1.col1,
MIN(t2.col2) AS col2
FROM table1 t1
LEFT JOIN table2 t2
ON t2.col1 = t1.col1
GROUP BY t1.col1
SQL Fiddle
Alternative solution, use a correlated sub-query:
select col1, (select min(col2) from table2 t2 where t2.col1 = t1.col1)
from table1 t1
If there are more columns in table2 you may want to use APPLY operator:
SELECT * FROM table1
OUTER APPLY(SELECT TOP 1 * FROM table2
WHERE table1.col1 = table2.col1 ORDER BY table2.col2)oa
Related
I'm trying this logic not sure what am missing in this case
select *
from table1 t1
join table2 t2 on t1.column1=t2.column1
where t1.column1 between 1 and 10 if t2.column2='value1'
and t1.column1 between 11 and 20 if t2.column2='value2'
You could use a case when aproach
CREATE tABLE table2(column1 int, column2 varchar(10))
INSERT INTO table2 VALUEs(1,'value1'),(2,'value1'),(13,'value2'),(44,'value2')
CREATE tABLE table1(column1 int)
INSERT INTO table1 VALUES (1),(2),(13),(44)
select *
from table1 t1
join table2 t2 on t1.column1=t2.column1
where
CASE WHEN t1.column1 between 1 and 10 AND t2.column2 like 'value1' THEN TRUE
WHEN t1.column1 between 11 and 20 AND t2.column2 like 'value2' THEN TRUE
ELSE FALSE END
column1 | column1 | column2
------: | ------: | :------
1 | 1 | value1
2 | 2 | value1
13 | 13 | value2
db<>fiddle here
I assume you've left out key details, like the ON for the JOIN and the wildcard for the LIKE, in the interest of simplicity.
select *
from table1 t1
join table2 t2
where (t1.column1 between 1 and 10 and t2.column2 like 'value1')
or (t1.column1 between 11 and 20 and t2.column2 like 'value2')
Probably very simple but given data of
TableA
FIELD1 | FIELD2
A | 1
A | 1
A | 2
B | 3
B | 3
C | 4
C | 5
How can I find the duplicate of Field 1 where Field 2 is different.
e.g from data above I want to return records 3 (A2) and 6 (C5)
Thanks in advance
You can use the following:
SELECT t1.* FROM table_name t1 INNER JOIN (
SELECT FIELD1, MIN(FIELD2) AS FIELD2
FROM table_name
GROUP BY FIELD1
) t2 ON t1.FIELD1 = t2.FIELD1 AND t1.FIELD2 <> t2.FIELD2
demo on dbfiddle.uk
You can use exists:
select a.*
from tableA a
where a.field2 > (select min(a2.field2)
from tableA a2
where a2.field1 = a.field1
);
You could also use window functions:
select a.*
from (select a.*,
min(a.field2) over (partition by field1) as min_field2
from tableA a
) a
where field2 > min_field2;
Can you let me how to build sql query for the below requirement:
I have 2 tables:
Table A:
col1 | Col2
------------
1 | a
2 | b
Table B:
Col1 | Col2
-----------
1 | 10
2 | 20
a | 30
b | 40
I need output like this:
Col1 | Col2
------------
1,a | 10,30
2,b | 20,40
Can anyone one help me please. Thanks
You can use this:
SELECT CONCAT(t1.col1, ' , ', t2.col1) AS Col1, CONCAT(t1.col2, ' , ', t2.col2) AS Col2
from
(select t1.col1, t2.col2 from tableA t1, tableB t2
where t1.col1 = t2.col1) as t1,
(select t1.col1 as col3, t2.col1, t2.col2 from tableA t1, tableB t2
where t1.col2 = t2.col1) as t2
where t1.col1 = t2.col3;
SQL Fiddle here:
http://sqlfiddle.com/#!9/459ae69/25
SQL DEMO
SELECT CONCAT(CONCAT(A."Col1", ' , '), A."Col2") AS Col1,
LISTAGG(B."Col2", ', ') WITHIN GROUP (ORDER BY B."Col1") Col2
FROM TableA A
JOIN TableB B
ON A."Col1" = B."Col1"
OR A."Col2" = B."Col1"
GROUP BY CONCAT(CONCAT(A."Col1", ' , '), A."Col2")
;
OUTPUT
| COL1 | COL2 |
|-------|--------|
| 1 , a | 10, 30 |
| 2 , b | 20, 40 |
Let's say I have 2 tables like this:
I want to join both #tmp1 & #tmp2 for Columns : Col2 & Col3 . But if the value of either of these columns is blank or Null, I want to ignore that column and just look at one.
So for example here, when I join where Col2 is ABC, I should get both DEF & Blank for Col3.
I hope I'm making some sense here. Apologize if it's not clear enough.
I can't tell from your example what columns you want to join but to solve the "null" problem you do it like this
SELECT *
FROM T1
JOIN T2 ON COALESCE(T1.COL1,T2.COL1) = T2.COL1
AND COALESCE(T1.COL2,T2.COL2) = T2.COL2
If T1.COL1 or T1.COL2 are null it will use the value of the table it is joining to. This allows null to be a "wildcard".
or if T2 is the table with nulls
SELECT *
FROM T1
JOIN T2 ON T1.COL1 = COALESCE(T2.COL1,T1.COL1)
AND T1.COL2 = COALESCE(T2.COL2,T1.COL2)
You can use union for this checking if at least 1 of the 2 columns is the same using exists:
select col1, col2, col3
from tmp1 t1
where exists (select 1
from tmp2 t2
where t1.col2 = t2.col2 or t1.col3 = t2.col3)
union
select col1, col2, col3
from tmp2 t2
where exists (select 1
from tmp1 t1
where t1.col2 = t2.col2 or t1.col3 = t2.col3)
Fiddle Demo
Results:
| col1 | col2 | col3 |
|-------|------|------|
| test1 | abc | def |
| test2 | aaa | bbb |
| test1 | abc | |
| test2 | ccc | bbb |
I need a query to produce a compare table between two tables.
Something like this:
table_1:
col1 | col2 | col3
a | 1 | a_comment
b | 2 | b_comment
table_2:
col1 | col2 | col3
a | 3 | a_comment
c | 4 | c_comment
Query result:
col1 | table_1.col2 | table_2.col2 | col3
a | 1 | 3 | a_comment
b | 2 | NULL | b_comment
c | NULL | 4 | c_comment
Also, I need to keep the order, s.t. if x in col1 is before y in col1 in any of the tables it will also be before it in the query result.
I tried to do it with FULL JOIN but it duplicates col1 and col3.
Thank you!
select t1.col1, t1.col2, t2.col2, t1.col3
from table_1 t1
left join table_2 t2
on t1.col1 = t2.col1
and t1.col3 = t2.col3
union
select t2.col1, t2.col2, t1.col2, t2.col3
from table_2 t2
left join table_1 t1
on t2.col1 = t1.col1
and t2.col3 = t1.col3
Full join is ok i think, you just have to select not all but just what you want, like
SELECT ISNULL(table_1.col1, table_2.col1) col1, table_1.col2, table2.col2, ISNULL(table_1.col3, table_2.col3) col3
ISNULL might be called different depending on what database system u use
SELECT col1
, t1.col2
, t2.col3
, col3
FROM table1 t1
FULL OUTER JOIN table2 t2
USING (col1, col3)