I would like to display 15 rows from queries but not first 15?
SELECT Abgänge.Vorgang, Abgänge.Date_SW_Drucken FROM Abgänge
WHERE Abgänge.Bezahlung = "Bar" LIMIT 34,15;
How to transform this to access 2010?
Limit:
LIMIT from_record-1, count_record
You can't, because there is no support for an offset in the Microsoft Access SELECT syntax. An option is to use TOP with offset + limit and skip offset rows manually. BTW: Using TOP or LIMIT without an ORDER BY is not advisable as it can lead to inconsistent results.
You could also combine two queries with TOP, first selecting limit + offset, and then selecting only offset, for example
SELECT TOP 15 ...
FROM (
SELECT TOP 49 ....
FROM sometable
ORDER BY somecolumn ASC
) a
ORDER BY somecolumn DESC
The only problem with this solution is that if there are less than 49 results from the subquery, then the offset will be less than 34.
If you need the result in a different order then you may need to add an additional 'layer' that applies that order.
Related
I have the following queries :
SELECT * FROM `datafusiontest-2897325.mergedquery.test_table LIMIT 10
SELECT * FROM `datafusiontest-2897325.mergedquery.test_table LIMIT 100
SELECT * FROM `datafusiontest-2897325.mergedquery.test_table LIMIT 10000
I am getting a different top result for each query.
As your query is not specifying an order, it is normal for results to be different each time - they are returning random rows from your table which meet the qualifying criteria.
To get the same top n returned you should add an ORDER BY clause, for example:
SELECT *
FROM `datafusiontest-2897325.mergedquery.test_table`
ORDER BY date
LIMIT 10
I need to find the longest movie and only print the title of that movie. However, when I try to do it, it just prints the title of every movie and all their lengths. So i'd like to know what I am doing wrong.
SELECT m.movie_title, MAX(m.movie_len)
FROM movie m
GROUP BY m.movie_title;
One method uses order by and limit:
select m.*
from movie m
order by length desc
limit 1;
MAX() is a function that operates on one column. It has no effect on other columns.
you must have clause where to limit rows, or use your query as sub query or if your db engine support use "limit 1 like Gordon Linoff writ, or select top 1 like in sql-serwer, or first over like in oracle... you didn't write db engine name...
I know the version is way too old (yea version 4!), but I have no choice.
How to limit my query for example 100 rows only for DB2 AS400?
FETCH FIRST n ROWS ONLY
and
ROW_NUMBER()
don't work.
Any ideas or workaround?
Here is a sample SQL query (does not work):
SELECT POLNOP FROM ZICACPTF.POLHDR FETCH FIRST 10 ROWS ONLY
It says
[SQL0199] Keyword FETCH not expected. Valid tokens: FOR WITH ORDER UNION OPTIMIZE.
There is no dbms support for this operation, check Version 4 DB2 UDB for AS/400 SQL Reference: No Limit, Top, First, ... reserved words.
You can try to limit rows via where clause, where sequence between 100 and 200. But this is an unreal scenario.
First work around is via cursor:
DECLARE ITERROWS INTEGER;
...
SET ITERROWS = 0;
DO WHILE (SUBSTR(SQLSTATE,1,2) = '00' and ITERROWS < 100
DO
...
SET ITERROWS = ITERROWS + 1;
second one, in your middleware language.
I hope someone post a clever workaround, but, in my opinion, they are not.
Solution only for > V4R4
Using FETCH FIRST [n] ROWS ONLY:
SELECT LASTNAME, FIRSTNAME, EMPNO, SALARY
FROM EMP
ORDER BY SALARY DESC
FETCH FIRST 10 ROWS ONLY;
Reference: publib.boulder.ibm.com
The difference I can see from your query to this example is that here we are using a ORDER BY clause - do you have the possibility to add a ORDER BY - it should do the trick. Referencing to: https://stackoverflow.com/a/16858430/1581725
To get ranges or also only the first 10 rows, you'd have to use ROW_NUMBER() (since v5r4):
SELECT
*
FROM (
SELECT ROW_NUMBER() OVER (ORDER BY {{table field}}) AS ROWNUM, * {{yourtable}}
) AS {{yourcursor}}
WHERE
{{yourcursor}}.ROWNUM>0 AND
{{yourcursor}}.ROWNUM<=10
Reference: blog.zanclus.com
Is it possible to retrieve a specific range of results? I know how to do TOP x but the result I will retrieve is WAY too big and will time out. I was hoping to be able to pick say the first 10,000 results then the next 10,000 and so on. Is this possible?
WITH Q AS (
SELECT ROW_NUMBER() OVER (ORDER BY ...some column) AS N, ...other columns
FROM ...some table
) SELECT * FROM Q WHERE N BETWEEN 1 AND 10000;
Read more about ROW_NUMBER() here: http://msdn.microsoft.com/en-us/library/ms186734.aspx
Practically all SQL DB implementations have a way of specifying the starting row to return, as well as the number of rows.
For example, in both mysql and postgres it looks like:
SELECT ...
ORDER BY something -- not required, but highly recommended
LIMIT 100 -- only get 100 rows
OFFSET 500; -- start at row 500
Note that normally you would include an ORDER BY to make sure your chunks are consistent
MS SQL Server (being a "pretend" DB) don't support OFFSET directly, but it can be coded using ROW_NUMBER() - see this SO post for more detail.
I'm writing a web application that should show very large results on a search query.
Say some queries will return 10.000 items.
I'd like to show those to users paginated; no problem so far: each page will be the result of a query with an appropriate LIMIT statement.
But I'd like to show clues about results in each page of the paginated query: some data from the first item and some from the last.
This mean that, for example, with a result of 10.000 items and a page size of 50 items, if the user asked for the first page I will need:
the first 50 items (the page requested by the user)
item 51 and 100 (the first and last of the second page)
item 101 and 151
etc
For efficiency reasons I want to avoid one query per row.
[edit] I also would prefer not downloading 10.000 results if I only need 50 + 10000/50*2 = 400
The question is: is there a single query I can issue to the RDBMS (mysql, by the way, but I'd prefer a cross-db solution) that will return only the data I need?
I can't use server side cursor, because not all dbs support it and I want my app to be database-agnostic.
Just for fun, here is the MSSQL version of it.
declare #pageSize as int; set #pageSize = 10;
declare #pageIndex as int; set #pageIndex = 0; /* first page */
WITH x AS
(
select
ROW_NUMBER() OVER (ORDER BY (created) ASC) AS RowNumber,
*
from table
)
SELECT * FROM x
WHERE
((RowNumber <= (#pageIndex+1)*#pageSize) AND (RowNumber >= #pageIndex*#PageSize+1))
OR
RowNumber % #pageSize = 1
OR
RowNumber % #pageSize = #pageSize-1
Note, that an ORDER BY is provided in the over clause.
Also note, that if you have gazillion rows, your result set will have millions. You need to maximize the result rows for practical reasons.
I have no idea how this could be a solved in generic SQL. (My bet: no way. Even simple pageing cannot be solved without DB-specific operators.)
UPDATE: I completely misread the initial question. You can do this using UNION and the LIMIT clause in MySQL, although it might be what you meant by "one query per row". The syntax would be like:
select FOO from BAZ limit 50
union
select FOO from BAZ limit 50, 1
union
select FOO from BAZ limit 99, 1
union
select FOO from BAZ limit 100, 1
union
select FOO from BAZ limit 149, 1
and so on and so forth. Since you're using UNION, you'll only need one roundtrip to the database. I'm not sure how MySQL will treat the various SELECT statements, though. It should be able to recognize that they are essentially the same query and use a cached query plan, but I don't work with MySQL enough to know if that's a reasonable expectation for its optimizer.
Obviously, to build this query in a general fashion, you'll first need to run a count query so you can calculate what your offsets will be.
This is definitely not a tractable problem for standard SQL, since the paging logic requires nonstandard features.