I want to write a query in SQL. Can someone help me for writing oracle sql query for below result table
Table 1 Data
prodno description
1 Laptop
2 Charger
3 Mouse
Table 2 Data
prodno prodset_no
1 1
2 1
3 1
1 2
3 2
1 3
2 3
Result Table
prodset_no prodset_desc
1 Laptop,Charger,Mouse
2 Laptop,Mouse
3 Laptop,Charger
JOIN the two table and then use listagg to produce comma separated output:
select t2.prodset_no,
listagg(t1.description, ',') within group (
order by t1.prodno
) prodset_desc
from table2 t2
join table1 t1 on t2.prodno = t1.prodno
group by t2.prodset_no;
Also, worth a note that the listagg has a limit of 4000 bytes. If you hit that limit, you can either use XMLAGG or rethink the problem and not do it in SQL at all but rather handle it in your application code.
Related
I'm wondering if it was doable (in one query if possible) to make the query return a default value if a row is missing ? For example takes these 2 tables and given my query takes 2 parameter (place_id and user_id)
T1
place_id / tag_id
1 2
1 3
1 4
2 4
3 2
4 5
T2
user_id / tag_id / count
100 2 1
100 3 20
200 4 30
200 2 2
300 5 22
As you see, the pair user/tag (100,4) is missing. What I would like to archive is a query that will return me these 3 results
tag_id / count
2 1
3 20
4 0
I know that i can do this with something like this but it doesn't really match the final result as it only works if i know in advance the tag_id... and obviously only return 1 row..:
SELECT T1.tag_id, T2.count
from T1 t1
left join T2 t2 on t1.tagId=t2.tag_id
where t1.place_id=1
UNION ALL
select tag_id,0
from T1
where not exist (select 1 from T2 where user_id=100 and tag_id=4)
and tag_id=4;
EDIT: My question was not complete and had missing cases
here is an example (curtesy of #a_horse_with_no_name) http://sqlfiddle.com/#!12/67042/4
Thank you!
The outer join will already take care of what you want.
As t1 is the "left table" of the join, all rows from t1 will be returned. Columns from the "right table" (t2 in your example) will then have a null value. So you only need to convert that null to a 0:
select t1.tag_id, coalesce(t2.cnt, 0)
from T1 t1
left join T2 t2 on t1.tag_Id=t2.tag_id
and t1.place_id = 1;
SQLFiddle example: http://sqlfiddle.com/#!12/ed7bf/1
Unrelated but:
Using count as a column name is a really bad idea, because it will require you to always enclose the column name in double quotes: t2."count" because it is a reserved word. Plus it doesn't really document the purpose of the column. You should find a better name for that.
How can I transform this table from this
id name
1 sam
2 nick
3 ali
4 farah
5 josef
6 fadi
to
id1 name1 id2 name2 id3 name3 id4 name4
1 sam 2 nick 3 ali 4 farah
5 josef 6 fadi
the reason i need this is i have a database and i need to do a mail merge using word and I want to print every 4 rows on one page, MS word can only print one row per page, so using an SQL query I want one row to represent 4 rows
thanks in advance
Ali
You don't need to create a query for this in Access. Word has a merge field called <<Next Record>> which forces moving to the next record. If you look at how label documents are created using the Mail Merge Wizard, you'll see that's how it's done.
Updated - Doing this in SQL
The columns in simple SELECT statements are derived from the columns from the underlying table/query (or from expressions). If you want to define columns based on the data, you need to use a crosstab query.
First create a query with a running count for each person (say your table is called People), and calculate the row and column position from the running count:
SELECT People.id, Count(*)-1 AS RunningCount, int(RunningCount/4) AS RowNumber, RunningCount Mod 4 AS ColumnNumber
FROM People
LEFT JOIN People AS People_1 ON People.id >= People_1.id
GROUP BY People.id;
(You won't be able to view this in the Query Designer, because the JOIN isn't comparing with = but with >=.)
This query returns the following results:
id Rank RowNumber ColumnNumber
1 0 0 0
2 1 0 1
3 2 0 2
4 3 0 3
5 4 1 0
6 5 1 1
Assuming this query is saved as Positions, the following query will return the results:
TRANSFORM First(Item) AS FirstOfItem
SELECT RowNumber
FROM (
SELECT ID AS Item, RowNumber, "id" &( ColumnNumber + 1) AS ColumnHeading
FROM Positions
UNION ALL SELECT Name, RowNumber, "name" & (ColumnNumber +1)
FROM Positions
INNER JOIN People ON Positions.id = People.id
) AS AllValues
GROUP BY AllValues.RowNumber
PIVOT AllValues.ColumnHeading In ("id1","name1","id2","name2","id3","name3","id4","name4");
The UNION is there so each record in the People table will have two columns - one with the id, and one with the name.
The PIVOT clause forces the columns to the specified order, and not in alphabetical order (e.g. id1, id2 ... name1, name2...)
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Select Records multiple times from table
I want to have my query return (multiple) rows for the value of TABLE_B.QTY.
TABLE A
SALESNR ITEMNR LINENR
100 B2001 1
101 B2002 2
102 A1021 3
TABLE B
LINENR COLOR QTY
1 WHITE 3
2 BLACK 1
3 BROWN 8
For instance, with the following query:
SELECT TABLE_A.SALESNR, TABLE_A.ITEMNR, TABLE_B.COLOR, TABLE_B.QTY
FROM TABLE_A INNER JOIN TABLE_B ON TABLE_B.LINENR = TABLE_A.LINENR
I get:
100 B2001 White 3
What I need is:
100 B2001 White 3
100 B2001 White 3
100 B2001 White 3
Is there a way to do this?
Can't think of the right keywords to Google this...
Thnx,
Mike
This will work as long as QTY is less than 2047
SELECT TABLE_A.SALESNR, TABLE_A.ITEMNR, TABLE_B.COLOR, TABLE_B.QTY
FROM TABLE_A
INNER JOIN TABLE_B ON TABLE_B.LINENR = TABLE_A.LINENR
INNER JOIN master..spt_values ON type = 'P' AND number < TABLE_B.QTY
use this if QTY exceeds 2047:
;WITH a AS
(
SELECT TABLE_A.SALESNR, TABLE_A.ITEMNR, TABLE_B.COLOR, TABLE_B.QTY, 1 row
FROM TABLE_A
INNER JOIN TABLE_B ON TABLE_B.LINENR = TABLE_A.LINENR
WHERE QTY > 0
union all
SELECT SALESNR, ITEMNR, COLOR, QTY, row+1
FROM a
WHERE QTY > row
)
SELECT SALESNR, ITEMNR, COLOR, QTY from a
OPTION (MAXRECURSION 0)
The cross join won't do it if you have one row in each table, which I interpret it as. I would suggest, if possible, to re-design your data model to solve this - or loop in code where you use this data.
You can loop in the T-SQL if absolutely needed.
regards, Olle
Can't seem to comment other peoples posts, just wanted to say, nice solution, to t-clausen.dk!
Let's say I have this table:
|Fld | Number|
1 5
2 2
And I want to make a select that retrieves as many Fld as the Number field has:
|Fld |
1
1
1
1
1
2
2
How can I achieve this? I was thinking about making a temporary table and instert data based on the Number, but I was wondering if this could be done with a single Select statement.
PS: I'm new to SQL
You can join with a numbers table:
SELECT Fld
FROM yourtable
JOIN Numbers
ON yourtable.Number <= Numbers.Number
A numbers table is just a table with a list of numbers:
Number
1
2
3
etc...
Not an great solution (since you still query your table twice, but maybe you can work from it)
SELECT t1.fld, t1.number
FROM table t1, (
SELECT ROWNUM number FROM dual
CONNECT BY LEVEL <= (SELECT MAX(number) FROM t1)) t2
WHERE t2.number<=t1.number
It generates maximum amount of rows needed and then filters it by each row.
I don't know if your RDBMS version supports it (although I rather suspect it does), but here is a recursive version:
WITH remaining (fld, times) as (SELECT fld, 1
FROM <table>
UNION ALL
SELECT a.fld, a.times + 1
FROM remaining as a
JOIN <table> as b
ON b.fld = a.fld
AND b.number > a.times)
SELECT fld
FROM remaining
ORDER BY fld
Given your source data table, it outputs this (count included for verification):
fld times
=============
1 1
1 2
1 3
1 4
1 5
2 1
2 2
I have result of two queries like:
Result of query 1
ID Value
1 4
2 0
3 6
4 9
Result of query 2
ID Value
1 6
2 4
3 0
4 1
I want to add values column "Value" and show final result:
Result of Both queries
ID Value
1 10
2 4
3 6
4 10
plz guide me...
select id, sum(value) as value
from (
select id, value from query1
uninon all
select id, value from query2
) x
group by id
Try using a JOIN:
SELECT
T1.ID,
T1.Value + T2.Value AS Value
FROM (...query1...) AS T1
JOIN (...query2...) AS T2
ON T1.Id = T2.Id
You may also need to consider what should happen if there is an Id present in one result but not in the other. The current query will omit it from the results. You may want to investigate OUTER JOIN as an alternative.
A not particularly nice but fairly easy to comprehend way would be:
SELECT ID,SUM(Value) FROM
(
(SELECT IDColumn AS ID,ValueColumn AS Value FROM TableA) t1
OUTER JOIN
(SELECT IDColumn AS ID,ValueColumn AS Value FROM TableB) t2
) a GROUP BY a.ID
It has the benefits of
a) I don't know your actual table structure so you should be able to work out how to get the two 'SELECT's working from your original queries
b) If ID doesn't appear in either table, that's fine