Here is my example script:
SELECT c2, c3, c4 FROM Table1
EXCEPT
SELECT c2, c3, c4 FROM Table2
I'm successfully returning unique records from the left table that do not also exist in the right table. Both tables have identical schemas and for the most part identical data. The problem is that the unique id (let's call it column c1) does not match, so I need to exclude it in the EXCEPT query above. How can I return the same set of records, but with the unique IDs included?
I was thinking of using temporary tables, cursors and long WHERE statements inside the cursor, but that doesn't seem like a very elegant solution. is there another way to accomplish this seemingly simple task?
Can you take your supplied query, and simply inner join it with table 1 to get your 'c1' column?
SELECT T1.* FROM Table1 T1 INNER JOIN(
SELECT c2, c3, c4 FROM Table1
EXCEPT
SELECT c2, c3, c4 FROM Table2
) a on a.c2=T1.c2 and a.c3=T1.c3 and a.c4=T1.c4
Try this
SELECT A.c1, A.c2, A.c3, A.c4
FROM Table1 A
LEFT OUTER JOIN Table2 B ON A.c2 = B.C2 AND A.c3 = B.C3 AND A.c4 = B.C4
WHERE B.c1 IS NULL;
You probably can accomplish it using "NOT EXISTS" rather than "EXCEPT" since with "NOT EXISTS" you can specify conditions. Here's a thread that points this out: EXCEPT vs NOT EXISTS.
This is kind of ugly and, on large tables lacking "useful" indexes, might perform very poorly, but it will do the work:
SELECT t1.c1, t1.c2, t1.c3, t1.c4
from Table1 t1
inner join (-- Unique tuples
SELECT c2, c3, c4 FROM Table1
EXCEPT
SELECT c2, c3, c4 FROM Table2
) xx
on xx.c2 = t1.c2
and xx.c3 = t1.c3
and xx.c5 = t1.c4
Related
I have two tables (t1 and t2). I want to print/keep all records from t1 (we'll treat t1 as the left table). I want to perform a JOIN with t1 and t2 on two columns, but there's a problem. Table t1 consists of columns c1 and c2. Table t2 consists of columns c3, c4, and c5. I want to perform a JOIN between t1 and t2 on c1 (from t1) and c3 (from t2), but I also want to do a JOIN between t1 and t2 on c2 (from t1) and c4 (from t2) if records from c1 and c3 do not match.
Here are the two tables. Completely fictitious, but applicable
to my real, work-related problem
The table below is what I want
All the records/rows from t1 are printed.
I greatly appreciate anyone who comes forward with query solutions. With that being said, is there a way to solve this problem without UNION? Also, I am using SQL Server.
Looking at the input and output data, I think you mean to compare c2 and c4 if c1 and c3 differ, not c1 and c2. I recreated the tables in sql and this code below gives the result you're looking for.
In that case you can just join and use an OR:
SELECT
*
FROM
t1
LEFT JOIN t2 ON
t1.c1 = t2.c3
OR t1.c2 = t2.c4;
I have a table in psql
where column T1 represent time (t5> t4> t3> t2> t1)
I want to remove all the rows except the one with the latest time, with same value of column C1 and C2,
i.e I want
Can someone please help me with the query for this. I am new to psql so i am not able to figure out this on my own.
Thanks.
Use distinct on:
select distinct on (c1, c2) t.*
from t
order by c1, c2, t1 desc;
In a delete, you can use:
delete from t
where t.t1 < (select max(t2.t1)
from t t2
where t2.c1 = t.c1 and t2.c2 = t.c2
);
I apologize for the basic non specific title. I can’t conceptualize how to ask this question or write the query I need in tsql. Any suggestions or guidance would be helpful. I have four columns that matter to me in a table:
c1(primarykey), c2, c3, c4
For any two rows, If c3 and c4 match but c2 doesn’t I want to return the rows. Amplify this to the entire table.
I’ve tried joining on a temp table then finding the difference through a left join on the table to itself but maybe I’m doing something incorrectly. Thank you in advance.
You could use:
WITH cte AS (
SELECT *, MIN(c2) OVER(PARTITION BY c3,c4) AS m, MAX(c2) OVER(PARTITION BY c3,c4) AS m2
FROM tab
)
SELECT *
FROM cte
WHERE m <> m2;
If you want to return the rows, then exists is a good way to go:
select t
from t
where exists (select 1
from t t2
where t2.c3 = t.c3 and t2.c4 = t.c4 and
t2.c2 <> t.c2
);
You do not mention NULL values in your question. If you have NULL values in any of the three columns, you would need to tweak the logic.
If you just wanted the c3/c4 pairs with different c2 values, you can use aggregation:
select c3, c4
from t
group by c3, c4
having min(c2) <> max(c2);
Finally, if you wanted to see pairs of non-matches on a single row, then:
select t.*, t2.c1, t2.c2
from t join
t t2
on t2.c3 = t.c3 and t2.c4 = t.c4 and
t2.c2 > t.c1;
With EXISTS:
select t.* from tablename t
where exists (
select 1 from tablename
where c2 <> t.c2 and c3 = t.c3 and c4 = t.c4
)
You can use Except
SELECT C1,C2,C3,C4 FROM TABLE1
EXCEPT
SELECT C4,C3,C2,C1 FROM TABLE1
This will check all the column values and if any of the value doesn't match then that record will be returns. More over you can add more columns to this query to match values.
In different SQL queries when I merge into one while follow the same sequence. Query are as follows-
select c1, c2, .....,
convert(varchar, t2.col1) AS col from table1 t1 inner join table2 t2 on t1.col2=t2.col1 AS col1,
....., c15 from table;
Here in above previous lots of columns before JOIN are there to fetch the data and mentioned as c1, c2, .... c15 are the column to fetching the values also lots of column are there after JOIN. But I want all these things into one SQL query. I stuck only on one JOINING two different tables as one column.
select all the columns as usual and at that time of JOINING write query like this-
select c1, c2, .....
convert(varchar, t2.col1) AS col,
...., c15 from table1
inner join on table2 on t1.col1 = t2.col2
The output you want merge into one.
I have two selects and I want to combine them in such a way, that only one row that has key column matched in both selects are returned(one row in first select and one row in 2nd select). Is there any built-in way in Oracle 10g to achieve this?
I have two sql as below
Query 1:
select c11, c12 from table t1
where c11=1000
Query 2:
select c21, c22
from t2
where c21=1000
I want to combine both query 1 and query 2 on key columns(OPTYREVN_OPTY_XI, OPTYREVN_SEGMENT_XI and OPTYREVN_OPTYREVNCRM_ID). My output should contain only the only one row which found in results of query 1 and query 2.
I am not sure to use UNION or Intersect or left outer join.
Kindly suggest me some solution which will be helpful in this scenario. Thanks.
So, If I got you right, you want to have c1 , c2 , c33 , c21 , c22 and c 23 on one line, if both queries return only one line and no information can link them, this should work...
SELECT a.* , b.*
FROM (select c1, c2, c33
from t1, t3
where c1= 1000 and c33 is null) a ,
(select c21, c22, c23
from t2
where c21= 1000) b
/*WHERE...*/ --you could always use some condition linking a and b
I think you would want to use a join:
SELECT c1, c2, c33, c21, c22, c23
FROM t1 INNER JOIN t3 ON <key columns>
INNER JOIN t2
ON t1.c1 = t2.c21
WHERE t1.c1 = 1000
AND t3.c33 IS NULL;