The UNIONALL is taking more time, below is example of query. as mentioned below table T1 having 4 records only, but in my query the T1 having almost 1.5 million records.
Is there any way to tune below query means instead unionall can we use any condition. Thanks!
CREATE TABLE T1 (ID INT, FROM_KEY INT,TO_KEY INT, IS_STATUS BIT)
INSERT INTO T1 VALUES(1, 50001,50002, 1)
INSERT INTO T1 VALUES(2, 50003,50004, 1)
INSERT INTO T1 VALUES(3, 50005,50006, 1)
INSERT INTO T1 VALUES(4, 50007,50008, 1)
DECLARE #KEY INT = 50002
SELECT TO_KEY FROM T1 WHERE TO_KEY=#KEY AND IS_STATUS=1
UNION ALL
SELECT FROM_KEY FROM T1 WHERE FROM_KEY=#KEY AND IS_STATUS=1
Can be simplified as:
SELECT #KEY
FROM T1
WHERE #KEY IN (TO_KEY, FROM_KEY)
AND IS_STATUS = 1
(Will only return the same row once if both to_key and from_key are equal to #key at the same time, while the UNION ALL query would return that row twice.)
Single pass query could be more optimal:
SELECT CASE WHEN N=0 THEN FROM_KEY ELSE TO_KEY END
FROM (SELECT * FROM T1 WHERE #KEY in (TO_KEY, FROM_KEY) AND IS_STATUS=1) AS A
JOIN (SELECT 0 N UNION ALL SELECT 1) AS B
ON (N=0 AND TO_KEY=#KEY) OR (N=1 AND FROM_KEY=#KEY)
But in general, if you wish to get help with query optimization, you have to provide much more information about sql server brand, version, data size, indexes and so on.
Related
I am trying to do the following:
Set the status column to 1 when the row in the first table (variable) does not exist in the second one.
I tried this:
update #table1
set status=1
where NOT EXISTS (select top 1 1 from #table2 where #table1.foo=#table2.foo)
But this doesn't even compile, not recognizing #table1 in the Where statement.
Must declare the scalar variable "#table1".
Any clue about this?
Your approach is fine. You just need table aliases because the # is used to in SQL Server to represent variables (scalars or tables) and is hence problematic for aliases:
update t1
set status = 1
from #table1 t1
where not exists (select 1 from #table2 t2 where t2.foo = t1.foo);
Note that the top 1 is unnecessary in the subquery.
You can do this kind of thing by joining the two tables with a LEFT JOIN and checking the right side for NULL:
UPDATE t1
SET t1.status=1
FROM #table1 t1
LEFT JOIN #table2 t2
ON t1.foo = t2.foo
WHERE t2.foo IS NULL
The specific error you got is because you haven't got a statement declaring #table1 as a table variable, like DECLARE #table1 TABLE (foo int) for example. If table1 is not a variable, you don't need the #.
no need any top inside scaler query
update #table1
set status=1
where NOT EXISTS (select 1 from #table2 where #table1.foo=#table2.foo)
cause exists return boolean
you could use below query
update #table1
set status=1
where #table1.foo not in ( select foo from #table2 where foo is not null)
There are multiple ways - inner query with NOT IN and NOT EXISTS and JOIN query:
update tab1 set status = 1 where name not in (select name from tab2);
update tab1 set status = 1 where not exists (select 1 from tab2 where tab1.name=tab2.name);
update tab1 set status = 1 from tab1 left outer join tab2 on tab1.name = tab2.name where tab2.name is null;
Sample schema to run above queries;
create table tab1(name varchar(30), status int);
create table tab2(name varchar(30));
insert into tab1 values('a', 5);
insert into tab1 values('b', 6);
insert into tab1 values('c', 7);
insert into tab1 values('d', 8);
insert into tab2 values('a');
insert into tab2 values('d');
You have to declare table1 and table2 variables
DECLARE #table1 YOUR_TABLE1_NAME;
DECLARE #table2 YOUR_TABLE2_NAME;
update #table1
set status=1
where NOT EXISTS (select top 1 from #table2 where #table1.foo=#table2.foo)
You should use alias name for both table.
DECLARE #TABLE_1 TABLE (DEPT_NAME VARCHAR(50),DEP_ID INT)
INSERT INTO #TABLE_1(DEPT_NAME,DEP_ID)
SELECT 'IT',1 UNION ALL
SELECT 'HR',2 UNION ALL
SELECT 'ACCOUNT',3 UNION ALL
SELECT 'ADMIN',4 UNION ALL
SELECT 'SALES',5 UNION ALL
SELECT 'CEO',7
DECLARE #TABLE_2 TABLE (E_ID INT,EMP_NAME VARCHAR(50),DEP_ID INT)
INSERT INTO #TABLE_2(E_ID,EMP_NAME,DEP_ID)
SELECT 1,'JHON',1 UNION ALL
SELECT 2,'LITA',2 UNION ALL
SELECT 3,'MATT',1 UNION ALL
SELECT 4,'JEFF',1 UNION ALL
SELECT 5,'BROCK',2 UNION ALL
SELECT 6,'BOB',5 UNION ALL
SELECT 7,'SAM',4 UNION ALL
SELECT 8,'DAVID',3 UNION ALL
SELECT 9,'JACK',1 UNION ALL
SELECT 10,'GARY',4 UNION ALL
SELECT 11,'DONALD',6
SELECT * FROM #TABLE_1 A WHERE NOT EXISTS (SELECT DEP_ID FROM #TABLE_2 B WHERE A.DEP_ID=B.DEP_ID )
Table1
Id bigint primary key identity(1,1)
Status nvarchar(20)
Insert dummy data
Insert into Table1 values ('Open') --1
Insert into Table1 values ('Open') --2
Insert into Table1 values ('Grabbed') --3
Insert into Table1 values ('Closed') --4
Insert into Table1 values ('Closed') --5
Insert into Table1 values ('Open') --6
How would I construct a single select statement which orders the data where records with 'Grabbed' status is first, followed by 'Closed', followed by 'Open' in SQL Server
Output:
Id Status
3 Grabbed
4 Closed
5 Closed
1 Open
2 Open
6 Open
I think you need something like this:
select *
from yourTable
order by case when Status = 'Grabbed' then 1
when Status = 'Closed' then 2
when Status = 'Open' then 3
else 4 end
, Id;
[SQL Fiddle Demo]
Another way is to using CTE like this:
;with cte as (
select 'Grabbed' [Status], 1 [order]
union all select 'Closed', 2
union all select 'Open', 3
)
select t.*
from yourTable t
left join cte
on t.[Status] = cte.[Status]
order by cte.[order], Id;
[SQL Fiddle Demo]
This could be done much better with a properly normalized design:
Do not store your Status as a textual content. Just imagine a typo (a row with Grabed)...
Further more a lookup table allows you to add side data, e.g. a sort order.
CREATE TABLE StatusLookUp(StatusID INT IDENTITY PRIMARY KEY /*you should name your constraints!*/
,StatusName VARCHAR(100) NOT NULL
,SortRank INT NOT NULL)
INSERT INTO StatusLookUp VALUES
('Open',99) --ID=1
,('Closed',50)--ID=2
,('Grabbed',10)--ID=3
CREATE TABLE Table1(Id bigint primary key identity(1,1) /*you should name your constraints!*/
,StatusID INT FOREIGN KEY REFERENCES StatusLookUp(StatusID));
Insert into Table1 values (1) --1
Insert into Table1 values (1) --2
Insert into Table1 values (3) --3
Insert into Table1 values (2) --4
Insert into Table1 values (2) --5
Insert into Table1 values (1) --6
SELECT *
FROM Table1 AS t1
INNER JOIN StatusLookUp AS s ON t1.StatusID=s.StatusID
ORDER BY s.SortRank;
I find that the simplest method uses a string:
order by charindex(status, 'Grabbed,Closed,Open')
or:
order by charindex(',' + status + ',', ',Grabbed,Closed,Open,')
If you are going to put values in the query, I think the easiest way uses values():
select t1.*
from t1 left join
(values ('Grabbed', 1), ('Closed', 2), ('Open', 3)) v(status, priority)
on t1.status = v.status
order by coalesce(v.priority, 4);
Finally. This need suggests that you should have a reference table for statuses. Rather than putting the string name in other tables, put an id. The reference table can have the priority as well as other information.
Try this:
select Id,status from tablename where status='Grabbed'
union
select Id,status from tablename where status='Closed'
union
select Id,status from tablename where status='Open'
I am trying to run a query given three tables.
DECLARE #TABLE1 TABLE (ID CHAR(2))
DECLARE #TABLE2 TABLE (ID CHAR(2))
DECLARE #TABLE3 TABLE (ID CHAR(2))
INSERT INTO #TABLE1 VALUES('1')
INSERT INTO #TABLE1 VALUES('2')
INSERT INTO #TABLE2 VALUES('1')
--NOTHING in TABLE3
I Need to get only the values that are present and ignore the null table. This doesn't work since TABLE3 has no values.
SELECT ID
FROM #TABLE1
INTERSECT
SELECT ID
FROM #TABLE2
INTERSECT
SELECT ID
FROM #TABLE3
**Result should be 1**
How do I ignore the any table if it's null but keep the other values?
Why not do a union of select distincts from each table, and then group that by ID and select count(*), and select only rows with count(*) equal to the maximum value of count(*) in the result?
It's a bit of a mess of subqueries at this point unfortunately but you should get the logic :)
Intersect is not going to work for you as you can't add conditions to it.
From what I understand you want to select all records where the ID appears in at least 2 of the tables. I am assuming that the ID is unique to each table.
The following works in MS SQL Server:
DECLARE #TABLE1 TABLE (ID CHAR(2))
DECLARE #TABLE2 TABLE (ID CHAR(2))
DECLARE #TABLE3 TABLE (ID CHAR(2))
INSERT INTO #TABLE1 VALUES('1')
INSERT INTO #TABLE1 VALUES('2')
INSERT INTO #TABLE2 VALUES('1')
--NOTHING in TABLE3
;WITH AllValues AS
(
SELECT ID
FROM #TABLE1
UNION ALL
SELECT ID
FROM #TABLE2
UNION ALL
SELECT ID
FROM #TABLE3
)
SELECT ID
FROM AllValues
GROUP BY ID
HAVING COUNT(*) > 1
Maybe... But the design of the system is extremely foreign; a real world example would help understand what you're trying to do.
Select count(*), ID FROM (
Select ID from #table1
UNION
Select ID from #table2
UNION
Select ID from #table3) Derived
Where RowNum =1
GROUP BY ID
ORder by count(*) DESC
Updated where clause was in wrong place
I have
SELECT * FROM Table1 WHERE Col1 IN(4,2,6)
I want to select and return the records with the specified order which i indicate in the IN clause
(first display record with Col1=4, Col1=2, ...)
I can use
SELECT * FROM Table1 WHERE Col1 = 4
UNION ALL
SELECT * FROM Table1 WHERE Col1 = 6 , .....
but I don't want to use that, cause I want to use it as a stored procedure and not auto generated.
I know it's a bit late but the best way would be
SELECT *
FROM Table1
WHERE Col1 IN( 4, 2, 6 )
ORDER BY CHARINDEX(CAST(Col1 AS VARCHAR), '4,2,67')
Or
SELECT CHARINDEX(CAST(Col1 AS VARCHAR), '4,2,67')s_order,
*
FROM Table1
WHERE Col1 IN( 4, 2, 6 )
ORDER BY s_order
You have a couple of options. Simplest may be to put the IN parameters (they are parameters, right) in a separate table in the order you receive them, and ORDER BY that table.
The solution is along this line:
SELECT * FROM Table1
WHERE Col1 IN(4,2,6)
ORDER BY
CASE Col1
WHEN 4 THEN 1
WHEN 2 THEN 2
WHEN 6 THEN 3
END
select top 0 0 'in', 0 'order' into #i
insert into #i values(4,1)
insert into #i values(2,2)
insert into #i values(6,3)
select t.* from Table1 t inner join #i i on t.[in]=t.[col1] order by i.[order]
Replace the IN values with a table, including a column for sort order to used in the query (and be sure to expose the sort order to the calling application):
WITH OtherTable (Col1, sort_seq)
AS
(
SELECT Col1, sort_seq
FROM (
VALUES (4, 1),
(2, 2),
(6, 3)
) AS OtherTable (Col1, sort_seq)
)
SELECT T1.Col1, O1.sort_seq
FROM Table1 AS T1
INNER JOIN OtherTable AS O1
ON T1.Col1 = O1.Col1
ORDER
BY sort_seq;
In your stored proc, rather than a CTE, split the values into table (a scratch base table, temp table, function that returns a table, etc) with the sort column populated as appropriate.
I have found another solution. It's similar to the answer from onedaywhen, but it's a little shorter.
SELECT sort.n, Table1.Col1
FROM (VALUES (4), (2), (6)) AS sort(n)
JOIN Table1
ON Table1.Col1 = sort.n
I am thinking about this problem two different ways because I can't decide if this is a programming problem or a data architecture problem. Check out the code below incorporating "famous" TV animals. Let's say that we are tracking dolphins, horses, bears, dogs and orangutans. We want to return only the horses, bears, and dogs in our query and we want bears to sort ahead of horses to sort ahead of dogs. I have a personal preference to look at this as an architecture problem, but can wrap my head around looking at it as a programming problem. Let me know if you have questions.
CREATE TABLE #AnimalType (
AnimalTypeId INT NOT NULL PRIMARY KEY
, AnimalType VARCHAR(50) NOT NULL
, SortOrder INT NOT NULL)
INSERT INTO #AnimalType VALUES (1,'Dolphin',5)
INSERT INTO #AnimalType VALUES (2,'Horse',2)
INSERT INTO #AnimalType VALUES (3,'Bear',1)
INSERT INTO #AnimalType VALUES (4,'Dog',4)
INSERT INTO #AnimalType VALUES (5,'Orangutan',3)
CREATE TABLE #Actor (
ActorId INT NOT NULL PRIMARY KEY
, ActorName VARCHAR(50) NOT NULL
, AnimalTypeId INT NOT NULL)
INSERT INTO #Actor VALUES (1,'Benji',4)
INSERT INTO #Actor VALUES (2,'Lassie',4)
INSERT INTO #Actor VALUES (3,'Rin Tin Tin',4)
INSERT INTO #Actor VALUES (4,'Gentle Ben',3)
INSERT INTO #Actor VALUES (5,'Trigger',2)
INSERT INTO #Actor VALUES (6,'Flipper',1)
INSERT INTO #Actor VALUES (7,'CJ',5)
INSERT INTO #Actor VALUES (8,'Mr. Ed',2)
INSERT INTO #Actor VALUES (9,'Tiger',4)
/* If you believe this is a programming problem then this code works */
SELECT *
FROM #Actor a
WHERE a.AnimalTypeId IN (2,3,4)
ORDER BY case when a.AnimalTypeId = 3 then 1
when a.AnimalTypeId = 2 then 2
when a.AnimalTypeId = 4 then 3 end
/* If you believe that this is a data architecture problem then this code works */
SELECT *
FROM #Actor a
JOIN #AnimalType at ON a.AnimalTypeId = at.AnimalTypeId
WHERE a.AnimalTypeId IN (2,3,4)
ORDER BY at.SortOrder
DROP TABLE #Actor
DROP TABLE #AnimalType
ORDER BY CHARINDEX(','+convert(varchar,status)+',' ,
',rejected,active,submitted,approved,')
Just put a comma before and after a string in which you are finding the substring index or you can say that second parameter.
And first parameter of CHARINDEX is also surrounded by , (comma).
I have got two table
create table t1(cid int, isnews int)
create table t2(nid int,cid int, isnews int)
situations is like this:
if t2 contain t2.cid = t1.cid then the t2.isnews = t1.news and
if t2 not contain cid of t1 then new record should be inserted in t2 and that t1.cid, t1.isnews should be inserted in t2..
and complete table should be done in single query... i have done the updation part but not able to do insertion part..
update query:
UPDATE t22
SET t22.isnews = t11.isnews
FROM t2 AS t22
JOIN t1 AS t11
ON t11.cid= t22.cid
i have prepared below cursor for insert... is it good? :
DECLARE #clntid INT
DECLARE #clntnewsltr INT
DECLARE clientnews CURSOR FOR
SELECT clientid,newsLetter
FROM clients
WHERE clientid NOT IN (SELECT clientid FROM clientprivacy)
OPEN clientnews
FETCH NEXT FROM clientnews INTO #clntid,#clntnewsltr
WHILE ##FETCH_STATUS = 0
BEGIN
INSERT INTO clientprivacy (clientId,tdNewsLetters) VALUES(#clntid, #clntnewsltr)
FETCH NEXT FROM clientnews INTO #clntid,#clntnewsltr
END
CLOSE clientnews
DEALLOCATE clientnews
I think this is the kind of thing you're after:
--INSERT t2 (cid, isnews)
SELECT t1.cid, t1.isnews
FROM t1
LEFT JOIN t2 ON t1.cid = t2.cid
WHERE t2.cid IS NULL
I've commented out the INSERT line - I recommend you run the SELECT on it's own first to check it does give you the correct result (all records from t1 that don't have a matching cid in t2).
I've assumed t2.nid is an IDENTITY column.
You will be so much better off without cursors :) Cursors take MUCH longer to run in large data sets.
It is true you can use a LEFT JOIN, but you can also use a SELECT in your WHERE clause. Most of the time it's a style choice.
CREATE TABLE table1(col_1 int, col_2 int)
CREATE TABLE table2(nid int, col_1 int, col_2 int)
INSERT INTO table2 (col_1,col_2)
SELECT col_1,col_2
FROM table1
WHERE col_1 NOT IN (SELECT col_1 FROM table2)