update set row value by rownum in oracle - oracle11gr2

Database version:oracle 11gr2,
my table is like:
create table t_test(t_id number,t_value number)
insert into t_test (t_id) values (1);
insert into t_test (t_id) values (2);
insert into t_test (t_id) values (6);
insert into t_test (t_id) values (10);
insert into t_test (t_id) values (3);
t_id t_value
1 null
2 null
6 null
10 null
3 null
My expecting update is like:
select t.t_id,row_number() over (order by t.t_id)
from t_test t
t_id row_number() over (order by t.t_id)
1 1
2 2
6 4
10 5
3 3
But analytic function is not allowed in update view:
update
(select t.value,row_number() over (order by t.t_id) rn
from t_test t)
set value=rn
Without no doubt,it causes ORA-01732.
How do I put my update query?


Try this
update t_test
set t_value = ( select rn
from ( select i.t_id, row_number() over (order by i.t_id) rn
from t_test i) tab
where tab.t_id= t_test.t_id )


THIS SOLUTION is not tested may need some minor changes !
CREATE OR REPLACE PROCEDURE SOME_PROC
BEGIN
FOR C IN ( select t.value,row_number() over (order by t.t_id) rn
from t_test t)
LOOP
BEGIN
UPDATE T_TEST
SET
T_VALUE=C.RN;
END;
END;

Related

How to show all columns with count?

In the result of my select I see 2 lines that's OK, but I want to see all columns like:
'Anne','Bauer','m1'
'Thomas','Neben','m3'
If (OBJECT_ID('tempdb..##test') Is Not Null)
Begin
Drop Table ##test
End
CREATE TABLE ##test (
givenname varchar(50),
surname varchar(50),
rann varchar(50)
);
INSERT INTO ##test VALUES ('Anne','Bauer','m1');
INSERT INTO ##test VALUES ('Klaus','Griebe','m2');
INSERT INTO ##test VALUES ('Thomas','Neben','m2');
INSERT INTO ##test VALUES ('Thomas','Neben','m3');
SELECT count(rann) as coun, rann
FROM ##test
group by rann
having count(rann) = 1
order by coun desc

You can try this:
select givenname,surname,rann from (
select *,count(*) over (partition by rann) rn from ##test
)t where rn=1

just use partition by with count
Select count(rann) over (partition by rann) [count], rann from ##test

What is the optimal way to get only latest ID's from table in SQL

I'm trying to get only a single row per Appointment Number in a table storing a history of appointments. It works fine with a few rows but then gets slower? Is this the best way to do this kind of check and I'm just missing some indexes or is there a better way?
DECLARE #temptable TABLE
(
id INT PRIMARY KEY NOT NULL
, ApptNumber INT NOT NULL
, ApptDate DATE NOT NULL
, Notes VARCHAR(50) NULL
)
INSERT INTO #temptable VALUES (1,1,'01-DEC-2018','First Appointment')
INSERT INTO #temptable VALUES (2,1,'01-DEC-2018','')
INSERT INTO #temptable VALUES (3,1,'01-DEC-2018','Rescheduled')
INSERT INTO #temptable VALUES (4,2,'02-DEC-2018','Second Appointment')
INSERT INTO #temptable VALUES (5,2,'02-DEC-2018','Cancelled')
INSERT INTO #temptable VALUES (6,3,'03-DEC-2018','Third Appointment')
INSERT INTO #temptable VALUES (7,4,'04-DEC-2018','Fourth Appointment')
SELECT * FROM #temptable
SELECT MAX(id) FROM #temptable GROUP BY ApptNumber
SELECT tt.* FROM #temptable tt
INNER JOIN (SELECT MAX(id) [Id] FROM #temptable GROUP BY ApptNumber) appts ON appts.Id = tt.id

Solution 1:
select * from (
SELECT f1.*, row_number() over(partition by ApptNumber order by id desc ) rang FROM #temptable f1
) tmp where rang=1

Solution 2:
with tmp as (
select ApptNumber, max(ID) MaxID
from #temptable
group by ApptNumber
)
select f1.* from #temptable f1 inner join tmp f2 on f1.ID=f2.MaxID

Solution 3:
select distinct f3.* from #temptable f1
cross apply
(
select top 1 * from #temptable f2
where f1.ApptNumber=f2.ApptNumber
order by f2.ID desc
) f3

Window function
SELECT tt.*
FROM (
SELECT *, row_number() over (partition by ApptNumber order by id desc) as rn
) tt
where tt.rn = 1

SQL Server select (top) two rows into two temp variables

I have a query which results in two or more rows (just one column) and I want to catch the first row value into first temp variable and second row value into second temp variable without using multiple times the select top 1 and select top 1 order by desc
Something like this;
Select row1 value into #tempvariable1, row2 value into #tempvariable2 from blah blah

You need somehow to identify the row (I am using a row ID in the example below, ordering by value - you can order by id or something else):
DECLARE #DataSource TABLE
(
[value] VARCHAR(12)
);
INSERT INTO #DataSource
VALUES ('value 1')
,('value 2')
,('value 3');
DECLARE #tempVariable1 VARCHAR(12)
,#tempVariable2 VARCHAR(12);
WITH DataSource ([value], [rowID]) AS
(
SELECT [value]
,ROW_NUMBER() OVER (ORDER BY [value])
FROM #DataSource
)
SELECT #tempVariable1 = IIF([rowID] = 1, [value], #tempVariable1)
,#tempVariable2 = IIF([rowID] = 2, [value], #tempVariable2)
FROM DataSource;
SELECT #tempVariable1
,#tempVariable2;

You can use a CTE where you will get the X values you need and then select from it:
declare #data table(id int);
insert into #data(id) values(8), (6), (4), (3);
with vals(id, n) as (
Select top(2) id, ROW_NUMBER() over(order by id)
From #data
)
Select #A = (Select id From vals Where n = 1)
, #B = (Select id From vals Where n = 2)
You could also use PIVOT:
Select #A = [1], #B = [2]
From (
Select id, ROW_NUMBER() over(order by id)
From #data
) v(id, n)
PIVOT (
max(id) FOR n in ([1], [2])
) as piv

You have two options
Let's say we test case is build as below
create table dbo.Test
(
value varchar(100) not null
)
GO
insert into dbo.Test
values
('A'),('B'),('NO THIS ONE'),('NO THIS ONE'),('NO THIS ONE')
GO
Now let's say you fetch your data as below
select t.value
from dbo.Test t
where t.value != 'NO THIS ONE'
GO
The first and easier option is to save the data in a temp table
declare #results as Table (value varchar(100))
insert into #results
select t.value
from dbo.Test t
where t.value != 'NO THIS ONE'
you still use TOP 1 BUT not in the entire data, only in the results.
Use TOP 1 to find the first result and a second TOP 1 where value is different from the first.
declare #A varchar(100), #B varchar(100)
set #A = (select top 1 r.value from #results r)
set #B = (select top 1 r.value from #results r where r.value != #A)
select #A, #B
GO
This approach have the advantage of performance.
Of course that don't work great if both values are equal. You can fix it by using a top 1 and ordering in the inverse order.
There's a better alternative using rownumber.
It works because if you set a variable when returning multiple rows the varible sticks with the last one (in fact it's reseted for each row iteration).
The case statement makes sure the variable #A is seted only on the first row iteration.
declare #A varchar(100), #B varchar(100)
/* This way #B receives the last value and #A the first */
select #B = t.value,
#A = (case when ROW_NUMBER() OVER(order by t.Value) = 1
then t.Value else #A
end)
from dbo.Test t
where t.value != 'NO THIS ONE'
select #A, #B

Is it possible to use MAX in update statement using sql?

i am trying to use the MAX function in sql statement. Here is what i am trying to do:
something like this:
UPDATE MainTable
SET [Date] = GETDATE()
where [ID] = Max
I know this is wrong specially where i put the where condition but cannot figure out how to use max and update in the same statement. thanks

UPDATE MainTable
SET [Date] = GETDATE()
where [ID] = (SELECT MAX([ID]) FROM MainTable)

One way
DECLARE #MaxID INT = (select MAX(id) FROM MainTable)
UPDATE MainTable
SET [Date] = GETDATE()
where [ID] = #MaxID
That is SQL 2008 syntax, in 2005 you need to do the declaraion and assignment of the variable in two steps
You could also use a common table expression
;WITH cte
AS (
SELECT TOP 1 * FROM MainTable
ORDER BY ID DESC
)
UPDATE cte SET [Date] = GETDATE()
Example you can run
CREATE TABLE testNow(id int)
INSERT testNow VALUES(1)
INSERT testNow VALUES(2)
;WITH cte
AS (
SELECT TOP 1 * FROM testNow
ORDER BY ID DESC
)
-- id with 2 will become 5
UPDATE cte SET ID = 5
SELECT * FROM testNow
Output
1
5

UPDATE MainTable
SET [Date] = GETDATE()
WHERE [ID] = (SELECT MAX(your column) FROM yourtable)

grouping, splitting, and counting rows

given this table and data:
DECLARE #Table table (RowID int, RowCode char(1), RowValue int);set nocount on
INSERT #Table VALUES ( 6,'A',3757 )
INSERT #Table VALUES ( 5,'A',37827)
INSERT #Table VALUES (14,'A',48411)
INSERT #Table VALUES ( 1,'A',48386)
INSERT #Table VALUES (20,'A',48450)
INSERT #Table VALUES ( 7,'A',46155)
INSERT #Table VALUES (13,'A',721 )
INSERT #Table VALUES ( 2,'A',49335)
INSERT #Table VALUES (15,'A',4700 )
INSERT #Table VALUES (19,'A',64416)
INSERT #Table VALUES ( 8,'A',27246)
INSERT #Table VALUES (12,'B',54929)
INSERT #Table VALUES (16,'B',3872 )
INSERT #Table VALUES ( 3,'C',728 )
INSERT #Table VALUES (11,'C',1050 )
INSERT #Table VALUES ( 9,'C',3191 )
INSERT #Table VALUES (17,'C',866 )
INSERT #Table VALUES ( 4,'C',838 )
INSERT #Table VALUES (10,'D',550 )
INSERT #Table VALUES (18,'D',1434 );set nocount off
I need this:
VVVVVVVV
RowID RowCode RowValue RowChunk
----- ------- -------- --------
1 A 48386 1
2 A 49335 1
5 A 37827 1
6 A 3757 1
7 A 46155 1
8 A 27246 2
13 A 721 2
14 A 48411 2
15 A 4700 2
19 A 64416 2
20 A 48450 3
12 B 54929 4
16 B 3872 4
3 C 728 5
4 C 838 5
9 C 3191 5
11 C 1050 5
17 C 866 5
10 D 550 6
18 D 1434 6
RowChunk starts at 1 and is incremented by 1 for each RowCode change and/or when there have been 5 of the same RowCode values.

Basically my solution uses the same approach as yours, only with slightly different devices employed.
WITH NumberedRows AS (
SELECT
RowID,
RowCode,
RowValue,
CodeChunk = (ROW_NUMBER() OVER (PARTITION BY RowCode ORDER BY RowID) - 1) / 5
FROM #Table
)
SELECT
RowID,
RowCode,
RowValue,
RowChunk = DENSE_RANK() OVER (ORDER BY RowCode, CodeChunk)
FROM NumberedRows

I don't think there's an analysis function, or any reasonable combination of such, which will address this. You'll have to do it RBAR with a cursor or, slightly faster in my experience, a loop.
This example of looping assumes that RowID is unique. If RowID is not the clustered PK, this will be very slow, so if that's the case you'll want to create a temp table.
DECLARE #RowID INT = (SELECT MIN(RowID) FROM #Table)
DECLARE #MaxRowID INT = (SELECT MAX(RowID) FROM #Table)
DECLARE #RowCode CHAR(1)
DECLARE #LastRowCode CHAR(1)
DECLARE #RowValue INT
DECLARE #Chunk INT = 0
DECLARE #RecsThisChunk INT
DECLARE #Results TABLE (RowID INT NOT NULL PRIMARY KEY, RowCode CHAR(1) NOT NULL, RowValue INT NOT NULL, Chunk INT NOT NULL)
WHILE #RowID <= #MaxRowID
BEGIN
-- Handle gaps in RowID
IF NOT EXISTS (SELECT * FROM #Table WHERE RowID = #RowID) GOTO EndOfLoop
-- Load values for this record
SELECT #RowCode = RowCode, #RowValue = RowValue FROM #Table WHERE RowID = #RowID
IF #LastRowCode IS NULL OR #RowCode <> #LastRowCode OR #RecsThisChunk = 5
BEGIN
-- Start a new chunk
SET #Chunk = #Chunk + 1
SET #RecsThisChunk = 1
END
ELSE
BEGIN
-- Same chunk
SET #RecsThisChunk = #RecsThisChunk + 1
END
SET #LastRowCode = #RowCode
INSERT INTO #Results (RowID, RowCode, RowValue, Chunk) VALUES (#RowID, #RowCode, #RowValue, #Chunk)
EndOfLoop:
SET #RowID = #RowID + 1
END
SELECT * FROM #Results
You may have tweak this a bit for 2005, I use 2008 routinely and don't recall all the little differences.
FYI, the results you show don't quite match the sample data.
Hope this helps! The only alternative I see is a cursor, or handling this in the application layer.

this does the trick without a loop:
;WITH NumberedRows AS (
SELECT
r.RowID, r.RowCode, r.RowValue, CEILING(ROW_NUMBER() OVER(PARTITION BY r.RowCode ORDER BY r.RowCode,r.RowID)/5.0) AS CodeRowChunk
FROM #Table r
)
, AllChunks AS (
SELECT r.*,ROW_NUMBER() OVER(ORDER BY RowCode,CodeRowChunk) AS ChunkRowNumber
FROM (SELECT DISTINCT
RowCode, CodeRowChunk
FROM NumberedRows) r
)
SELECT
a.RowID, RowCode, a.RowValue,
(SELECT ChunkRowNumber FROM AllChunks c WHERE c.RowCode=a.RowCode and c.CodeRowChunk=a.CodeRowChunk) AS RowChunk
FROM NumberedRows a

This is the answer you are looking for :
create Table [table] (RowID int, RowCode char(1), RowValue int)
INSERT [Table] VALUES ( 6,'A',3757 )
INSERT [Table] VALUES ( 5,'A',37827)
INSERT [Table] VALUES (14,'A',48411)
INSERT [Table] VALUES ( 1,'A',48386)
INSERT [Table] VALUES (20,'A',48450)
INSERT [Table] VALUES ( 7,'A',46155)
INSERT [Table] VALUES (13,'A',721 )
INSERT [Table] VALUES ( 2,'A',49335)
INSERT [Table] VALUES (15,'A',4700 )
INSERT [Table] VALUES (19,'A',64416)
INSERT [Table] VALUES ( 8,'A',27246)
INSERT [Table] VALUES (12,'B',54929)
INSERT [Table] VALUES (16,'B',3872 )
INSERT [Table] VALUES ( 3,'C',728 )
INSERT [Table] VALUES (11,'C',1050 )
INSERT [Table] VALUES ( 9,'C',3191 )
INSERT [Table] VALUES (17,'C',866 )
INSERT [Table] VALUES ( 4,'C',838 )
INSERT [Table] VALUES (10,'D',550 )
INSERT [Table] VALUES (18,'D',1434 )
IF object_id('tempdb..#tempTable') IS NOT NULL
BEGIN
DROP TABLE #tempTable
END
CREATE TABLE #tempTable
(RowID int, RowCode char(1), RowValue int,RowChunk int)
INSERT INTO #tempTable
select RowID,RowCode,RowValue,null from [table]
declare #RowId int
declare #RowCode char(1)
declare #Count int
declare #CurrentCode char(1)
declare #CountCurrent int
set #Count=1
set #CurrentCode=1
set #CountCurrent=0
DECLARE contact_cursor CURSOR FOR
SELECT RowID,RowCode FROM [table]
OPEN contact_cursor
FETCH NEXT FROM contact_cursor into #RowId,#RowCode
set #CurrentCode=#RowCode
WHILE ##FETCH_STATUS = 0
BEGIN
if(#CurrentCode=#RowCode)
begin
if(#CountCurrent=5)
begin
set #CountCurrent=1
set #Count=#Count+1
update #tempTable set RowChunk=#Count where RowID=#RowID
end
else
begin
set #CountCurrent=#CountCurrent+1
update #tempTable set RowChunk=#Count where RowID=#RowID
end
end
else
begin
set #CurrentCode=#RowCode
set #CountCurrent=1
set #Count=#Count+1
update #tempTable set RowChunk=#Count where RowID=#RowID
end
FETCH NEXT FROM contact_cursor into #RowId,#RowCode
END
CLOSE contact_cursor
DEALLOCATE contact_cursor
select * from #tempTable
GO

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