I need to return two tables from an sp. And I need the second one to use an attribute from the result of the first one. I can do it this way.
select UberId, ... from A where ...;
select * from B where UberId in (select UberId from A where ...);
But I'm wondering if I can do it without running the bracketed subquery but instead just using the output of the first query directly. Would it be more performant?
Use a temp table.
select UberId, ...
into #t
from A
where ...;
select * from #t;
select * from B
where UberId in (select UberId from #t);
Related
I have a show columns query that works fine:
SHOW COLUMNS IN table
but it fails when trying to put it in a CTE, like this:
WITH columns_table AS (
SHOW COLUMNS IN table
)
SELECT * from columns_table
any ideas why and how to fix it?
Using RESULT_SCAN:
Returns the result set of a previous command (within 24 hours of when you executed the query) as if the result was a table. This is particularly useful if you want to process the output from any of the following:
SHOW or DESC[RIBE] command that you executed.
SHOW COLUMNS IN ...;
WITH columns_table AS (
SELECT *
FROM table(RESULT_SCAN(LAST_QUERY_ID()))
)
SELECT *
FROM columns_table;
CTE requires select clause and we cannot use SHOW COLUMN IN CTE's and as a alterative use INFORMATION_SCHEMA to retrieve metadata .Like below:
WITH columns_table AS (
Select * from INTL_DB.INFORMATION_SCHEMA.COLUMNS where TABLE_NAME='CURRENCIES'
)
SELECT * from columns_table;
I'm trying to write a SP that will allow users to search on multiple name strings, but supports LIKE functionality. For example, the user's input might be a string 'Scorsese, Kaurismaki, Tarkovsky'. I use a split function to turn that string into a table var, with one column, as follows:
part
------
Scorsese
Kaurismaki
Tarkovsky
Then, normally I would return any values from my table matching any of these values in my table var, with an IN statement:
select * from myTable where lastName IN (select * from #myTableVar)
However, this only returns exact matches, and I need to return partial matches. I'm looking for something like this, but that would actually compile:
select * from myTable where CONTAINS(lastName, select * from #myTableVar)
I've found other questions where it's made clear that you can't combine LIKE and IN, and it's recommended to use CONTAINS. My specific question is, is it possible to combine CONTAINS with a table list of values, as above? If so, what would that syntax look like? If not, any other workarounds to achieve my goal?
I'm using SQL Server 2016, if it makes any difference.
You can use EXISTS
SELECT * FROM myTable M
WHERE
EXISTS( SELECT * FROM #myTableVar V WHERE M.lastName like '%'+ V.part +'%' )
Can your parser built the entire statement? Will that get you what you want?
select *
from myTable
where CONTAINS
(lastName,
'"Scorsese" OR "Kaurismaki" OR "Tarkovsky"'
)
This can be done using CHARINDEX function combined with EXISTS:
select *
from myTable mt
where exists(select 1 from #myTableVar
where charindex(mt.lastName, part) > 0
or charindex(part, mt.lastName) > 0)
You might want to omit one of the conditions in the inner query, but I think this is what you want.
I have the following SQL query:
Declare #Total_SysDown as int,
#Login_SysDown as int
Set #Total_SysDown = (SELECT SCHED_SYS_DOWN FROM AGT_SC AS S)
Set #Login_SysDown = (SELECT SYS_DOWN FROM AGT_AC AS A)
Insert Into dbo.DATA(DATE,ID,LNAME,FNAME,Total_SysDown,Login_SysDown)
Select C.DATE,C.ID,E.Last_Name,E.First_Name,#Total_SysDown #Login_SysDown
From dbo.AGT as C Inner Join dbo.EMP as E ON C.ID = E.ID
Group by C.ID,C.DATE,E.Last_Name,E.First_Name
This or just the variables with the Select statement gives me an error of Subquery returned than 1 value. From what I understand, this means that I should be inserting one record at a time, but I am unsure how to do this. Is there a while statement I should be putting in, or are my variables actually hindering me in the first place?
At least one of the queries:
(SELECT SCHED_SYS_DOWN FROM AGT_SC AS S)
(SELECT SYS_DOWN FROM AGT_AC AS A)
returns more than 1 row, so you cannot assign it to a scalar variable.
As a temporary solution you can do SELECT TOP 1 to make sure each query returns at most one row.
I don't think the problem is with your INSERT statement at all.
Your problem is in the SET Statements. The SELECT SCHED_SYS_DOWN FROM AGT_SC AS S statement or the other statement is returning more than one value.
When you use SET you are assigning ONE value to the variable. Your SELECT is returning multiple values. Change your query to return only one row.
You're receiving this error because your subqueries return more than one record:
Set #Total_SysDown = (SELECT SCHED_SYS_DOWN FROM AGT_SC AS S)
Set #Login_SysDown = (SELECT SYS_DOWN FROM AGT_AC AS A)
To use variables here, you will need to ensure that only one record is returned from the query, either by using a WHERE clause, TOP 1, or something else. I can't tell for sure by your example, but it sounds like you should be joining those tables to your SELECT query.
SELECT ...
FROM dbo.AGT agt
INNER JOIN AGT_SC sc
ON sc.<joining column> = <joining table>.<joining column>
INNER JOIN AGT_AC ac
ON ac.<joining column> = <joining table>.<joining column>
This is probably a really simple question, but I don't write stored procedures often and I'm a bit mystified...
After doing various stuff, the concluding bit of the SP ends by returning counts or sums from several different tables. The obvious approach is:
select SUM(ThisCol) as ThisResult from...
select SUM(ThatCol) as ThatResult from...
select count(DISTINCT OtherCol) as OtherResult from...
Of course, this creates multiple recordsets - one for each select plus one containing zero. This is a bit silly since each recordset contains exactly one value. I would much prefer to return a single recordset with multiple columns: ThisResult, ThatResult and OtherResult.
Is that possible?
You can use variables
DECLARE #thisResult INT
DECLARE #thatResult INT
DECLARE #otherResult INT
select #thisResult = SUM(ThisCol) as ThisResult from...
select #thatResult = SUM(ThatCol) as ThatResult from...
select #otherResult = count(OtherCol) as OtherResult from...
SELECT #thisResult AS 'thisResult', #thatResult AS 'thatResult', #otherResult AS 'otherResult'
SELECT T1.ThisResult, T2.ThatResult, T3.OtherResult
FROM (select SUM(ThisCol) as ThisResult from...) T1,
(select SUM(ThatCol) as ThatResult from...) T2,
(select count(DISTINCT OtherCol) as OtherResult from...) T3
Because each table contains only 1column & 1 value, you do a cross join of all 3 and put each value in a column in the result table.
If you're using SQL Server, you can select these quantities again as your last statement.
Select ThisResult, ThatResult, OtherResult
You don't have to specify a table
Is there a better solution to the problem of looking up multiple known IDs in a table:
SELECT * FROM some_table WHERE id='1001' OR id='2002' OR id='3003' OR ...
I can have several hundreds of known items. Ideas?
SELECT * FROM some_table WHERE ID IN ('1001', '1002', '1003')
and if your known IDs are coming from another table
SELECT * FROM some_table WHERE ID IN (
SELECT KnownID FROM some_other_table WHERE someCondition
)
The first (naive) option:
SELECT * FROM some_table WHERE id IN ('1001', '2002', '3003' ... )
However, we should be able to do better. IN is very bad when you have a lot of items, and you mentioned hundreds of these ids. What creates them? Where do they come from? Can you write a query that returns this list? If so:
SELECT *
FROM some_table
INNER JOIN ( your query here) filter ON some_table.id=filter.id
See Arrays and Lists in SQL Server 2005
ORs are notoriously slow in SQL.
Your question is short on specifics, but depending on your requirements and constraints I would build a look-up table with your IDs and use the EXISTS predicate:
select t.id from some_table t
where EXISTS (select * from lookup_table l where t.id = l.id)
For a fixed set of IDs you can do:
SELECT * FROM some_table WHERE id IN (1001, 2002, 3003);
For a set that changes each time, you might want to create a table to hold them and then query:
SELECT * FROM some_table WHERE id IN
(SELECT id FROM selected_ids WHERE key=123);
Another approach is to use collections - the syntax for this will depend on your DBMS.
Finally, there is always this "kludgy" approach:
SELECT * FROM some_table WHERE '|1001|2002|3003|' LIKE '%|' || id || '|%';
In Oracle, I always put the id's into a TEMPORARY TABLE to perform massive SELECT's and DML operations:
CREATE GLOBAL TEMPORARY TABLE t_temp (id INT)
SELECT *
FROM mytable
WHERE mytable.id IN
(
SELECT id
FROM t_temp
)
You can fill the temporary table in a single client-server roundtrip using Oracle collection types.
We have a similar issue in an application written for MS SQL Server 7. Although I dislike the solution used, we're not aware of anything better...
'Better' solutions exist in 2008 as far as I know, but we have Zero clients using that :)
We created a table valued user defined function that takes a comma delimited string of IDs, and returns a table of IDs. The SQL then reads reasonably well, and none of it is dynamic, but there is still the annoying double overhead:
1. Client concatenates the IDs into the string
2. SQL Server parses the string to create a table of IDs
There are lots of ways of turning '1,2,3,4,5' into a table of IDs, but the Stored Procedure which uses the function ends up looking like...
CREATE PROCEDURE my_road_to_hell #IDs AS VARCHAR(8000)
AS
BEGIN
SELECT
*
FROM
myTable
INNER JOIN
dbo.fn_split_list(#IDs) AS [IDs]
ON [IDs].id = myTable.id
END
The fastest is to put the ids in another table and JOIN
SELECT some_table.*
FROM some_table INNER JOIN some_other_table ON some_table.id = some_other_table.id
where some_other_table would have just one field (ids) and all values would be unique