Having a (MySQL) audit table containing rows that are similar, is it possible to view only those columns that have different values?
For example, a table containing four columns where column key is primary key, and column id is the identifier to match rows:
key id col1 col2
1 123 B C
2 123 A C
3 456 B C
4 789 B A
5 789 B B
6 987 A C
In the example above I need the query to return only row 1, 2, 4, and 5 as they have matching id, and differing values in col1 and col2, ie B,A and B,A.
key id col1 col2
1 123 B
2 123 A
4 789 A
5 789 B
I know it might not be very efficient solution, but gives what you want. HERE try this:
SELECT A.ID, (CASE A.col1 WHEN B.col1 THEN NULL ELSE B.col1 END), (CASE A.col2 WHEN B.col2 THEN NULL ELSE B.col2 END) FROM tblName A
FULL OUTER JOIN tblName B
ON
A.ID=B.ID
WHERE
(A.col1=B.col1 AND A.Col2<>B.Col2)
OR
(A.col2<>B.col2 AND A.Col1=B.Col1)
INNER JOIN should give same result
This is a bit contrived, in the sense that adding more rows will give very different results - but anyway...
SELECT x.my_key
, x.id
, IF(y.col1=x.col1,'',x.col1) col1
, IF(y.col2=x.col2,'',x.col2) col2
FROM my_table x
JOIN my_table y
ON y.id = x.id
AND y.my_key <> x.my_key
WHERE (y.col1 <> x.col1 OR y.col2 <> x.col2)
ORDER
BY my_key;
Thanks for all responses which guided me.
Using your suggestions I made the sql like this:
SELECT
T1.KEY,
T1.ID,
CASE T2.COL1_DISTINCT_VALUES WHEN 1 THEN NULL ELSE T1.COL1 END AS COL1,
CASE T2.COL2_DISTINCT_VALUES WHEN 1 THEN NULL ELSE T1.COL2 END AS COL2
FROM
TAB1 T1
INNER JOIN
(
SELECT
ID,
COUNT(DISTINCT COL1) AS COL1_DISTINCT_VALUES,
COUNT(DISTINCT COL2) AS COL2_DISTINCT_VALUES
FROM
TAB1
GROUP BY
ID
) T2
ON T1.ID=T2.ID
WHERE
T2.COL1_DISTINCT_VALUES > 1
OR T2.COL2_DISTINCT_VALUES > 1
ORDER BY
KEY,ID;
Related
So I want to select rows from table where col1 or col2 equals to variable, but if there is already row selected where col1 equals to variable (variable X) and col2 is anything else (variable Y) then it won't select another row where col2 equals to variable X and col1 equals to that variable Y. Everything ordered by column TIME descending.
Let's say this is my table:
COL1 COL2 TIME COL4
1 2 0 A
1 2 1 B
2 1 2 C
1 3 3 D
3 1 4 E
4 2 5 F
3 4 6 G
1 2 7 H
4 1 8 I
And let's say that variable X equals to 1, then I want to have these rows:
COL1 COL2 TIME COL4
4 1 8 I
1 2 7 H
3 1 4 E
So it won't show me this row
COL1 COL2 TIME COL4
2 1 2 C
because there is already a combination where col1/col2 is 2/1 or 1/2.
Sorry if I explained it in a bad way, but I can't think of better explanation.
Thank you guys.
Making a couple of key assumptions...
SELECT a.*
FROM my_table a
JOIN
( SELECT MAX(time) time
FROM my_table
WHERE 1 IN (COL1,COL2)
GROUP
BY LEAST(col1,col2)
, GREATEST(col1,col2)
) b
ON b.time = a.time;
EDIT: I posted this answer when it was thought that OP's database was SQL Server. But as it turns out, the database is MySQL.
I think this query should do it:
select t.col1, t.col2, t.time, t.col4
from (select t.*,
row_number() over (
partition by
case when col1 < col2 then col1 else col2 end,
case when col1 < col2 then col2 else col1 end
order by time desc) as rn
from tbl t
where t.col1 = x or t.col2 = x) t
where t.rn = 1
order by t.time desc
The key part is defining the row_number partition by clause in such a way that (1, 2) is considered equivalent to (2, 1), which is what the case statements do. Once the partitioning works correctly, you just need to keep the first row of every "partition" (where t.rn = 1) to exclude duplicate rows.
Below is the structure of my table. I want to retrieve records even if the condition do not match.
I have been using left join but the record is dropping since the condition do not match. Instead of dropping the record, I want to display a null value for tht column.
As far as checked, left outer join is the way to go. I am doing the same but still not getting the desired output.
table 1
Col1 Col2 Col3 Col4
1 74 Desc 1 10/01/2015
2 85 Desc 2 09/01/2016
3 96 Desc 3 12/01/2015
table 2
Col4 Col5 Col6
AB 1 10/01/2015
CD 2 09/01/2016
EF 3 7/01/2015
GH 3 08/01/2015
Expected:
c1 dt exp
1 10/01/2015 AB
2 09/01/2016 CD
3 12/01/2015
Getting:
c1 dt exp
1 10/01/2015 AB
2 09/01/2016 CD
select tab1.col1 as c1, tab1.col4 as dt, tab2.col4 as exp
from tab1, tab 2
where tab1.col1 = tab2.col5
and tab1.col4 = tab2.col6(+)
Thanks,
Not sure about your goal. But here is my guess:
http://sqlfiddle.com/#!9/8422d/2
SELECT *
FROM t1
LEFT JOIN t2
ON t1.col1 = t2.col5
AND t1.col4 = t2.col6
What you want is called a left join, in your example you can get the expected result with;
select *
from tab1 left join tab2
on tab1.id = tab2.tab1_id and ...etc
I need a query which should results a fields that are not found in another table. Let say,
table 1:
comp col1 col2 col3 col4
----------------------------------
nam1 1 1 b c
nam2 0 0 abc c
nam3 1 1 a c
nam4 1 1 b c
nam5 0 0 c c
table2:
name col1 col2
----------------------
b 3 f
a 4 f
c 5 f
result:
comp col3 col4
----------------------
nam2 abc c
the result be based on col3,col1=0,col2=0 on first table and name in second table..abc is not found in table2...
thanks in advance.
The question is not very clear, but if I understood you correctly, you want to select all rows from table1 where col1 and col2 are both 0, and col3 is not contained in the name column of table2. If so, your query should be simple enough:
SELECT comp, col3, col4
FROM table1
WHERE col1 = 0
AND col2 = 0
AND col3 NOT IN (SELECT name FROM table2);
As per the explanation the joining key between table1 and table2 is
table1.col3 = table2.name
Using this you can use the following query
select
t1.comp,
t1.col3,
t1.col4
from table1 t1
left join table2 t2 on t2.name = t1.col3
where t2.name is null
How do I select rows where two columns are unique?
Given table
id col1 col2
1 a 222
2 b 223
3 c 224
4 d 224
5 b 225
6 e 226
How do remove the duplicates in col1 and the duplicates in col2, to get rows unique to whole table,
So that result is
id col1 col2
1 a 222
6 e 226
Is there a better way than using sub queries?
SELECT * FROM table WHERE id
IN (SELECT id FROM table WHERE col1
IN (SELECT col1 FROM table GROUP BY col1 HAVING(COUNT(col1)=1))
GROUP BY col2 HAVING(COUNT(col2)=1))
This should work using exists:
select *
from yourtable y
where not exists (
select 1
from yourtable y2
where y.id != y2.id
and (y.col1 = y2.col1
or y.col2 = y2.col2))
SQL Fiddle Demo
Here's an alternative solution using an outer join as I've read mysql sometimes doesn't do well with exists:
select *
from yourtable y
left join yourtable y2 on y.id != y2.id
and (y.col1 = y2.col1
or y.col2 = y2.col2)
where y2.id is null;
More Fiddle
You can also do this by aggregating along each dimension:
select t.*
from table t join
(select col1
from table t
group by col1
having count(*) = 1
) t1
on t.col1 = t1.col1 join
(select col2
from table t
group by col2
having count(*) = 1
) t2
on t.col2 = t2.col2;
This method seems like a very direct translation of the user requirements.
I have a table 1 with a one to many relationship to table 2.
Table 1 also has a one to many relationship with table 3
I want to combine the results of the join but all im getting is repeated values
Here is the structure:
table 1
reportnumber
1
2
3
table 2
reportnumber col1
1 a
1 b
2 c
3 a
table 3
reportnumber col2
1 x
1 y
1 z
2 w
expected result set
reportnumber col1 col2
1 a x
1 b y
1 z
2 c w
3 a
I'm sure this is possible with a left outer join but i just cant get the syntax right
Any clues?
This is what im trying
select * from table1 a
left outer join table2 b on a.reportnumber=b.reportnumber
left outer join table3 on a.reportnumer=c.reportnumber
But the results look like this
reportnumber col1 col2
1 a x
1 a y
1 a z
1 b x
1 b y
1 b z
...
This isn't easy in MySQL, but you can do it with variables. This has little to do with a join. Or, it has a lot to do with join, but you don't have the right join keys and you don't have full outer join.
The solution is to enumerate the rows from each table with the data columns. Then aggregate using the enumeration and reportnumber:
select reportnumber, max(col1) as col1, max(col2) as col2
from ((select t2.reportnumber, col1, null as col2, #rn2 := #rn2 + 1 as rn
from table2 t2 cross join
(select #rn2 := 0) const
) union all
(select t3.reportnumber, null, t3.col2, #rn3 := #rn3 + 1 as rn
from table3 t3 cross join
(select #rn3 := 0) const
)
) t
group by reportnumber, rn;