I have the task to find out if all columns in a SQL Server table have exact the same value. The table content is created by a stored procedure and can vary in the number of columns. The first column is an ID, the second and the following columns must be compared if the all columns have exact the same value.
At the moment I do not have a clue how to achieve this.
The best solution would be to display only the rows, which have different values in one or multiple columns except the first column with ID.
Thank you so much for your help!!
--> Edit: The table looks this:
ID Instance1 Instance2 Instance3 Instance4 Instance5
=====================================================
A 1 1 1 1 1
B 1 1 0 1 1
C 55 55 55 55 55
D Driver Driver Driver Co-driver Driver
E 90 0 90 0 50
F On On On On On
The result should look like this, only the rows with one or multiple different column values should be display.
ID Instance1 Instance2 Instance3 Instance4 Instance5
=====================================================
B 1 1 0 1 1
D Driver Driver Driver Co-driver Driver
E 90 0 90 0 50
My table has more than 1000 rows and 40 columns
you can achieve this by using row_number()
Try the following code
With c as(
Select id
,field_1
,field_2
,field_3
,field_n
,row_number() over(partition by field_1,field_2,field_3,field_n order by id asc) as rn
From Table
)
Select *
From c
Where rn = 1
row_number with partition is going to show you if the field is repeated by assigning a number to a row based on field_1,field_2,field_3,field_n, for example if you have 2 rows with same field values the inner query is going to show you
rn field_1 field_2 field_3 field_n id
1 x y z a 5
2 x y z a 9
After that on the outer part of the query pick rn = 1 and you are going to obtain a query without repetitions based on fields.
Also if you want to delete repeated numbers from your table you can apply
With c as(
Select id
,field_1
,field_2
,field_3
,field_n
,row_number() over(partition by field_1,field_2,field_3,field_n order by id asc) as rn
From Table
)
delete
From c
Where rn > 1
The best solution would be to display only the rows, which have different values in one or multiple columns except the first column with ID.
You may be looking for a the following simple query, whose WHERE clause filters out rows where all fields have the same value (I assumed 5 fields - id not included).
SELECT *
FROM mytable t
WHERE NOT (
field1 = field2
AND field1 = field3
AND field1 = field4
AND field1 = field5
);
Related
How to repeat rows based on column value in snowflake using sql.
I tried a few methods but not working such as dual and connect by.
I have two columns: Id and Quantity.
For each ID, there are different values of Quantity.
So if you have a count, you can use a generator:
with ten_rows as (
select row_number() over (order by null) as rn
from table(generator(ROWCOUNT=>10))
), data(id, count) as (
select * from values
(1,2),
(2,4)
)
SELECT
d.*
,r.rn
from data as d
join ten_rows as r
on d.count >= r.rn
order by 1,3;
ID
COUNT
RN
1
2
1
1
2
2
2
4
1
2
4
2
2
4
3
2
4
4
Ok let's start by generating some data. We will create 10 rows, with a QTY. The QTY will be randomly chosen as 1 or 2.
Next we want to duplicate the rows with a QTY of 2 and leave the QTY =1 as they are.
Obviously you can change all parameters above to suit your needs - this solution works super fast and in my opinion way better than table generation.
Simply stack SPLIT_TO_TABLE(), REPEAT() with a LATERAL() join and voila.
WITH TEN_ROWS AS (SELECT ROW_NUMBER()OVER(ORDER BY NULL)SOME_ID,UNIFORM(1,2,RANDOM())QTY FROM TABLE(GENERATOR(ROWCOUNT=>10)))
SELECT
TEN_ROWS.*
FROM
TEN_ROWS,LATERAL SPLIT_TO_TABLE(REPEAT('hire me $10/hour',QTY-1),'hire me $10/hour')ALTERNATIVE_APPROACH;
I am using oracle 12c database and I have a table with the following structure:
Id NUMBER
SeqNo NUMBER
Val NUMBER
Valid VARCHAR2
A composite primary key is created with the field Id and SeqNo.
I would like to fetch the data with Valid = 'Y' and apply ketset pagination with a page size of 3. Assume I have the following data:
Id SeqNo Val Valid
1 1 10 Y
1 2 20 N
1 3 30 Y
1 4 40 Y
1 5 50 Y
2 1 100 Y
2 2 200 Y
Expected result:
----------------------------
Page 1
----------------------------
Id SeqNo Val Valid
1 1 10 Y
1 3 30 Y
1 4 40 Y
----------------------------
Page 2
----------------------------
Id SeqNo Val Valid
1 5 50 Y
2 1 100 Y
2 2 200 Y
Offset pagination can be done like this:
SELECT * FROM table ORDER BY Id, SeqNo OFFSET 3 ROWS FETCH NEXT 3 ROWS ONLY;
However, in the actual db it has more than 5 millions of records and using OFFSET is going to slow down the query a lot. Therefore, I am looking for a ketset pagination approach (skip records using some unique fields instead of OFFSET)
Since a composite primary key is used, I need to offset the page with information from more than 1 field.
This is a sample SQL that should work in PostgreSQL (fetch 2nd page):
SELECT * FROM table WHERE (Id, SeqNo) > (1, 4) AND Valid = 'Y' ORDER BY Id, SeqNo LIMIT 3;
How do I achieve the same in oracle?
Use row_number() analytic function with ceil arithmetic fuction. Arithmetic functions don't have a negative impact on performance, and row_number() over (order by ...) expression automatically orders the data without considering the insertion order, and without adding an extra order by clause for the main query. So, consider :
select Id,SeqNo,
ceil(row_number() over (order by Id,SeqNo)/3) as page
from tab
where Valid = 'Y';
P.S. It also works for Oracle 11g, while OFFSET 3 ROWS FETCH NEXT 3 ROWS ONLY works only for Oracle 12c.
Demo
You can use order by and then fetch rows using fetch and offset like following:
Select ID, SEQ, VAL, VALID FROM TABLE
WHERE VALID = 'Y'
ORDER BY ID, SEQ
--FETCH FIRST 3 ROWS ONLY -- first page
--OFFSET 3 ROWS FETCH NEXT 3 ROWS ONLY -- second pages
--OFFSET 6 ROWS FETCH NEXT 3 ROWS ONLY -- third page
--Update--
You can use row_number analytical function as following.
Select id, seqNo, Val, valid from
(Select t.*,
Row_number(order by id, seq) as rn from table t
Where valid = 'Y')
Where ceil(rn/3) = 2 -- for page no. 2
Cheers!!
I want to setup a simple query that will filter out any row that contains "A" in the ItemID, but my issue is I also do NOT want to display any journal ID from a different row since it matched "A". I tried googling the solution, but I am sure I am not using the right keywords to find it. I am using microsoft sql 2008, but I am not a database admin so I am not to familiar. I tried using distinct, and I also tried group by, but in this situation it does not work.
This is a simplified version of the table that I am working with:
JournalID ItemID PrimaryKEY
1 A 1
1 B 2
2 A 3
2 C 4
3 B 5
4 D 6
And here is how I would like to make it look:
JournalID ItemID PrimaryKEY
3 B 5
4 D 6
This will exclude any rows where the ItemID is 'A' and also any rows that have the same JournalID as a row where a ItemID was 'A'.
SELECT JournalID, ItemID, PrimaryKEY
FROM TABLE
WHERE JournalID NOT IN (Select JournalID FROM TABLE WHERE ItemID = 'A')
Try this:
SELECT *
FROM table_name
WHERE JournalID
NOT IN (SELECT JournalID
FROM table_name
WHERE ItemID = 'A')
I have two Tables.
table A
id name Size
===================
1 Apple 7
2 Orange 15
3 Banana 22
4 Kiwi 2
5 Melon 28
6 Peach 9
And Table B
id size
==============
1 14
2 5
3 31
4 9
5 1
6 16
7 7
8 25
My desired result will be (add one column to Table A, which is the number of rows in Table B that have size smaller than Size in Table A)
id name Size Num.smaller.in.B
==============================
1 Apple 7 2
2 Orange 15 5
3 Banana 22 6
4 Kiwi 2 1
5 Melon 28 7
6 Peach 9 3
Both Table A and B are pretty huge. Is there a clever way of doing this. Thanks
Use this query it's helpful
SELECT id,
name,
Size,
(Select count(*) From TableB Where TableB.size<Size)
FROM TableA
The standard way to get your result involves a non-equi-join, which will be a product join in Explain. First duplicating 20,000 rows, followed by 7,000,000 * 20,000 comparisons and a huge intermediate spool before the count.
There's a solution based on OLAP-functions which is usually quite efficient:
SELECT dt.*,
-- Do a cumulative count of the rows of table #2
-- sorted by size, i.e. count number of rows with a size #2 less size #1
Sum(CASE WHEN NAME = '' THEN 1 ELSE 0 end)
Over (ORDER BY SIZE, NAME DESC ROWS Unbounded Preceding)
FROM
( -- mix the rows of both tables, an empty name indicates rows from table #2
SELECT id, name, size
FROM a
UNION ALL
SELECT id, '', size
FROM b
) AS dt
-- only return the rows of table #1
QUALIFY name <> ''
If there are multiple rows with the same size in table #2 you better count before the Union to reduce the size:
SELECT dt.*,
-- Do a cumulative sum of the counts of table #2
-- sorted by size, i.e. count number of rows with a size #2 less size #1
Sum(CASE WHEN NAME ='' THEN id ELSE 0 end)
Over (ORDER BY SIZE, NAME DESC ROWS Unbounded Preceding)
FROM
( -- mix the rows of both tables, an empty name indicates rows from table #2
SELECT id, name, size
FROM a
UNION ALL
SELECT Count(*), '', SIZE
FROM b
GROUP BY SIZE
) AS dt
-- only return the rows of table #1
QUALIFY NAME <> ''
There is no clever way of doing that, you just need to join the tables like this:
select a.*, b.size
from TableA a join TableB b on a.id = b.id
To improve performance you'll need to have indexes on the id columns.
maybe
select
id,
name,
a.Size,
sum(cnt) as sum_cnt
from
a inner join
(select size, count(*) as cnt from b group by size) s on
s.size < a.size
group by id,name,a.size
if you're working with large tables. Indexing table b's size field could help. I'm also assuming the values in table B converge, that there's many duplicates you don't care about, other than you want to count them.
sqlfiddle
#Ritesh solution is perfectly correct, another similar solution is using CROSS JOIN as shown below
use tempdb
create table dbo.A (id int identity, name varchar(30), size int );
create table dbo.B (id int identity, size int);
go
insert into dbo.A (name, size)
values ('Apple', 7)
,('Orange', 15)
,('Banana', 22)
,('Kiwi', 2 )
,('Melon', 28)
,('Peach', 6 )
insert into dbo.B (size)
values (14), (5),(31),(9),(1),(16), (7),(25)
go
-- using cross join
select a.*, t.cnt
from dbo.A
cross apply (select cnt=count(*) from dbo.B where B.size < A.size) T(cnt)
try this query
SELECT
A.id,A.name,A.size,Count(B.size)
from A,B
where A.size>B.size
group by A.size
order by A.id;
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