I can easily get a random record with this:
SELECT * FROM MyTable ORDER BY NewId()
I can easily get a record with "today's date" with this:
SELECT * FROM MyTable WHERE MyDate = "2010-24-08" -- db doesn't store times
But how would I combind the two?
Get 1 random record... anything with today's date.
If none are found... get 1 random record from yesterday (today-1).
If none are found... get 1 random record from etc, etc, today-2
... until 1 record is found.
Just make the day date the primary order by condition:
select top(1) *
from Table
order by Date desc, newid();
If you store the dates as full day and time, you need to round them out to the day part only: cast (Date as DATE) in SQL 2008 or cast(floor(cast(Date as FLOAT)) as DATETIME) in pre-2008.
Use the TOP operator:
SELECT TOP 1 *
FROM MyTable
WHERE MyDate = "2010-24-08"
ORDER BY NEWID()
...combined with the ORDER BY NEWID(). Without the ORDER BY, you'd get the first inserted row/record of the records returned by the filteration in most cases typically, but the only way to ensure order is with an ORDER BY clause.
SQL Server 2005+ supports brackets on the TOP value, so you can use a variable in the brackets without needing to use dynamic SQL.
Does this give you what you want?
SELECT TOP 1 *
FROM MyTable
ORDER BY MyDate desc, NewId()
This assumes there are no dates later than today.
Related
I have a simple, but large, database that I need to write a SQL statement for. The statements needs to do the following:
Get the 15 most popular values for a field.
From those 15, get the count that value has appeared within a particular time period.
My table contains both a Date and a Value field. I am able to extract the 15 most popular values, or get the count for a particular value in a given time period. I do not know how to put the two together.
This is my current SQL:
SELECT
Count( Value ) AS Total,
Value AS Value
FROM
Database
GROUP BY
Value
ORDER BY
Total DESC
LIMIT 15
That will get my most popular 15. But from that, I want to display the COUNT() that each Value is between two dates.
Would this require a HAVING clause?
I simplified the previous solution (which would also do a job) a little bit:
SELECT
Value,
Count(*) as TotalInPeriod
FROM Database
WHERE Value in (SELECT Value FROM Database GROUP BY Value
ORDER BY count(*) DESC LIMIT 15)
AND date_field BETWEEN your_start_date and your_end_date
GROUP BY Value
Try something like this. Make an inner query that finds the top 15 values overall, and join it to the main set to limit it to those values.
SELECT
Count( Value) as TotalInPeriod,
Value as Value
FROM
Database a
JOIN (SELECT
Count( Value ) AS Total,
Value AS Value
FROM
Database
GROUP BY
Value
ORDER BY
Total DESC
LIMIT 15) as topValues
ON
a.Value = topValues.Value
WHERE
a.date_field BETWEEN your_start_date and your_end_date
GROUP BY
a.Value
I want to fire a Query "SELECT * FROM TABLE" but select only from row N+1. Any idea on how to do this?
For SQL Server 2012 and above, use this:
SELECT *
FROM Sales.SalesOrderHeader
ORDER BY OrderDate
OFFSET (#Skip) ROWS FETCH NEXT (#Take) ROWS ONLY
https://stackoverflow.com/a/19669165/1883345
SQL Server:
select * from table
except
select top N * from table
Oracle up to 11.2:
select * from table
minus
select * from table where rownum <= N
with TableWithNum as (
select t.*, rownum as Num
from Table t
)
select * from TableWithNum where Num > N
Oracle 12.1 and later (following standard ANSI SQL)
select *
from table
order by some_column
offset x rows
fetch first y rows only
They may meet your needs more or less.
There is no direct way to do what you want by SQL.
However, it is not a design flaw, in my opinion.
SQL is not supposed to be used like this.
In relational databases, a table represents a relation, which is a set by definition. A set contains unordered elements.
Also, don't rely on the physical order of the records. The row order is not guaranteed by the RDBMS.
If the ordering of the records is important, you'd better add a column such as `Num' to the table, and use the following query. This is more natural.
select *
from Table
where Num > N
order by Num
Query: in sql-server
DECLARE #N INT = 5 --Any random number
SELECT * FROM (
SELECT ROW_NUMBER() OVER(ORDER BY ID) AS RoNum
, ID --Add any fields needed here (or replace ID by *)
FROM TABLE_NAME
) AS tbl
WHERE #N < RoNum
ORDER BY tbl.ID
This will give rows of Table, where rownumber is starting from #N + 1.
In order to do this in SQL Server, you must order the query by a column, so you can specify the rows you want.
Example:
select * from table order by [some_column]
offset 10 rows
FETCH NEXT 10 rows only
Do you want something like in LINQ skip 5 and take 10?
SELECT TOP(10) * FROM MY_TABLE
WHERE ID not in (SELECT TOP(5) ID From My_TABLE ORDER BY ID)
ORDER BY ID;
This approach will work in any SQL version. You need to stablish some order (by Id for example) so all rows are provided in a predictable manner.
I know it's quite late now to answer the query. But I have a little different solution than the others which I believe has better performance because no comparisons are performed in the SQL query only sorting is done. You can see its considerable performance improvement basically when value of SKIP is LARGE enough.
Best performance but only for SQL Server 2012 and above. Originally from #Majid Basirati's answer which is worth mentioning again.
DECLARE #Skip INT = 2, #Take INT = 2
SELECT * FROM TABLE_NAME
ORDER BY ID ASC
OFFSET (#Skip) ROWS FETCH NEXT (#Take) ROWS ONLY
Not as Good as the first one but compatible with SQL Server 2005 and above.
DECLARE #Skip INT = 2, #Take INT = 2
SELECT * FROM
(
SELECT TOP (#Take) * FROM
(
SELECT TOP (#Take + #Skip) * FROM TABLE_NAME
ORDER BY ID ASC
) T1
ORDER BY ID DESC
) T2
ORDER BY ID ASC
What about this:
SELECT * FROM table LIMIT 50 OFFSET 1
This works with all DBRM/SQL, it is standard ANSI:
SELECT *
FROM owner.tablename A
WHERE condition
AND n+1 <= (
SELECT COUNT(DISTINCT b.column_order)
FROM owner.tablename B
WHERE condition
AND b.column_order>a.column_order
)
ORDER BY a.column_order DESC
PostgreSQL: OFFSET without LIMIT
This syntax is supported, and it is in my opinion the cleanest API compared to other SQL implementations as it does not introduce any new keywords:
SELECT * FROM mytable ORDER BY mycol ASC OFFSET 1
that should definitely be standardized.
The fact that this is allowed can be seen from: https://www.postgresql.org/docs/13/sql-select.html since LIMIT and OFFSET can be given independently, since OFFSET is not a sub-clause of LIMIT in the syntax specification:
[ LIMIT { count | ALL } ]
[ OFFSET start [ ROW | ROWS ] ]
SQLite: negative limit
OFFSET requires LIMIT in that DBMS, but dummy negative values mean no limit. Not as nice as PostgreSQL, but it works:
SELECT * FROM mytable ORDER BY mycol ASC LIMIT -1 OFFSET 1
Asked at: SQLite with skip (offset) only (not limit)
Documented at: https://sqlite.org/lang_select.html
If the LIMIT expression evaluates to a negative value, then there is no upper bound on the number of rows returned.
MySQL: use a huge limit number
Terrible API design, the documentation actually recommends it:
SELECT * FROM tbl LIMIT 1,18446744073709551615;
Asked at: MySQL skip first 10 results
Node.js Sequelize ORM implements it
That ORM allows e.g. findAll({offset: without limit:, and implements workarounds such as the ones mentioned above for each different DBMS.
In Faircom SQL (which is a pseudo MySQL), i can do this in a super simple SQL Statement, just as follows:
SELECT SKIP 10 * FROM TABLE ORDER BY Id
Obviously you can just replace 10 with any declared variable of your desire.
I don't have access to MS SQL or other platforms, but I'll be really surprised MS SQL doesn't support something like this.
DECLARE #Skip int= 2, #Take int= 2
SELECT * FROM TABLE_NAME
ORDER BY Column_Name
OFFSET (#Skip) ROWS FETCH NEXT (#Take) ROWS ONLY
try below query it's work
SELECT * FROM `my_table` WHERE id != (SELECT id From my_table LIMIT 1)
Hope this will help
You can also use OFFSET to remove the 1st record from your query result like this-
Example - find the second max salary from the employee table
select distinct salary from employee order by salary desc limit 1 OFFSET 1
For SQL Server 2012 and later versions, the best method is #MajidBasirati's answer.
I also loved #CarlosToledo's answer, it's not limited to any SQL Server version but it's missing Order By Clauses. Without them, it may return wrong results.
For SQL Server 2008 and later I would use Common Table Expressions for better performance.
-- This example omits first 10 records and select next 5 records
;WITH MyCTE(Id) as
(
SELECT TOP (10) Id
FROM MY_TABLE
ORDER BY Id
)
SELECT TOP (5) *
FROM MY_TABLE
INNER JOIN MyCTE ON (MyCTE.Id <> MY_TABLE.Id)
ORDER BY Id
I am storing the date as "14-02-2013" in date column of my table. Now when I get the date using "ORDER BY" then it should display the output as
14-02-2013
15-03-2013
24-05-2013
How to write the query for this. i.e getting order by day and month.
Any suggestion will be helpful.
Use DATE (or DATETIME) type in your column. Otherwise you will have to perform operations on string representation of date, which is not cool and will cost some extra time to perform
Try one of following:
Select * from Table1 order by date(dtcolumn) Asc
Select * from Table1 order by strftime('%d-%m-%Y', dtcolumn)
Try this query
Select * from Table1 Order By mydatecol Asc
Given you store your date as a temporal data type you can use
select * from your_date_table order by date(your_date_column) ASC
If you store it as a string(which you should not do), you can try
select * from your_date_table order by your_date_column ASC
Here is the doc for the sqlite date and time functions
Which of the following two SQL statements will return the desired result set (i.e. the ten rows with Status=0 and the highest StartTimes)?
Will both statements always return the same result set (StartTime is unique)?
SELECT *
FROM MyTable
WHERE Status=0
AND ROWNUM <= 10
ORDER BY StartTime DESC
SELECT *
FROM (
SELECT *
FROM MyTable
WHERE Status=0
ORDER BY StartTime DESC
)
WHERE ROWNUM <= 10
Background
My DBAdmin told me that the first statement will first limit the table to 10 rows and than order those random rows by StartTime, which is definitly not what I want.
From what I learned in that answer, the order by clause of the second statement is redundant and could be removed by an optimizer, which is also not what I want.
I asked a similar question concering the limit clause in a query to a SQLite database and am interested in understanding any differences to the above statements (using limit Vs rownum) used with an oracle db.
Your Second Query will work
Because in the first ,the first ten rows with Status 0 are selected and then the order by is done in that case the first ten rows fetched need not be in the highest order
What is the most efficient way to read the last row with SQL Server?
The table is indexed on a unique key -- the "bottom" key values represent the last row.
If you're using MS SQL, you can try:
SELECT TOP 1 * FROM table_Name ORDER BY unique_column DESC
select whatever,columns,you,want from mytable
where mykey=(select max(mykey) from mytable);
You'll need some sort of uniquely identifying column in your table, like an auto-filling primary key or a datetime column (preferably the primary key). Then you can do this:
SELECT * FROM table_name ORDER BY unique_column DESC LIMIT 1
The ORDER BY column tells it to rearange the results according to that column's data, and the DESC tells it to reverse the results (thus putting the last one first). After that, the LIMIT 1 tells it to only pass back one row.
If some of your id are in order, i am assuming there will be some order in your db
SELECT * FROM TABLE WHERE ID = (SELECT MAX(ID) FROM TABLE)
I think below query will work for SQL Server with maximum performance without any sortable column
SELECT * FROM table
WHERE ID not in (SELECT TOP (SELECT COUNT(1)-1
FROM table)
ID
FROM table)
Hope you have understood it... :)
I tried using last in sql query in SQl server 2008 but it gives this err:
" 'last' is not a recognized built-in function name."
So I ended up using :
select max(WorkflowStateStatusId) from WorkflowStateStatus
to get the Id of the last row.
One could also use
Declare #i int
set #i=1
select WorkflowStateStatusId from Workflow.WorkflowStateStatus
where WorkflowStateStatusId not in (select top (
(select count(*) from Workflow.WorkflowStateStatus) - #i ) WorkflowStateStatusId from .WorkflowStateStatus)
You can use last_value: SELECT LAST_VALUE(column) OVER (PARTITION BY column ORDER BY column)...
I test it at one of my databases and it worked as expected.
You can also check de documentation here: https://msdn.microsoft.com/en-us/library/hh231517.aspx
OFFSET and FETCH NEXT are a feature of SQL Server 2012 to achieve SQL paging while displaying results.
The OFFSET argument is used to decide the starting row to return rows from a result and FETCH argument is used to return a set of number of rows.
SELECT *
FROM table_name
ORDER BY unique_column desc
OFFSET 0 Row
FETCH NEXT 1 ROW ONLY
SELECT TOP 1 id from comission_fees ORDER BY id DESC
In order to retrieve the last row of a table for MS SQL database 2005, You can use the following query:
select top 1 column_name from table_name order by column_name desc;
Note: To get the first row of the table for MS SQL database 2005, You can use the following query:
select top 1 column_name from table_name;
If you don't have any ordered column, you can use the physical id of each lines:
SELECT top 1 sys.fn_PhysLocFormatter(%%physloc%%) AS [File:Page:Slot],
T.*
FROM MyTable As T
order by sys.fn_PhysLocFormatter(%%physloc%%) DESC
SELECT * from Employees where [Employee ID] = ALL (SELECT MAX([Employee ID]) from Employees)
This is how you get the last record and update a field in Access DB.
UPDATE compalints SET tkt = addzone &'-'& customer_code &'-'& sn where sn in (select max(sn) from compalints )
If you have a Replicated table, you can have an Identity=1000 in localDatabase and Identity=2000 in the clientDatabase, so if you catch the last ID you may find always the last from client, not the last from the current connected database.
So the best method which returns the last connected database is:
SELECT IDENT_CURRENT('tablename')
Well I'm not getting the "last value" in a table, I'm getting the Last value per financial instrument. It's not the same but I guess it is relevant for some that are looking to look up on "how it is done now". I also used RowNumber() and CTE's and before that to simply take 1 and order by [column] desc. however we nolonger need to...
I am using SQL server 2017, we are recording all ticks on all exchanges globally, we have ~12 billion ticks a day, we store each Bid, ask, and trade including the volumes and the attributes of a tick (bid, ask, trade) of any of the given exchanges.
We have 253 types of ticks data for any given contract (mostly statistics) in that table, the last traded price is tick type=4 so, when we need to get the "last" of Price we use :
select distinct T.contractId,
LAST_VALUE(t.Price)over(partition by t.ContractId order by created ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
from [dbo].[Tick] as T
where T.TickType=4
You can see the execution plan on my dev system it executes quite efficient, executes in 4 sec while the exchange import ETL is pumping data into the table, there will be some locking slowing me down... that's just how live systems work.
It is very simple
select top 10 * from TableName order by 1 desc
SELECT * FROM TABLE WHERE ID = (SELECT MAX(ID) FROM TABLE)
I am pretty sure that it is:
SELECT last(column_name) FROM table
Becaause I use something similar:
SELECT last(id) FROM Status