here is one query that returns only 1 column called datapath:
SELECT --assumes number not at end of string
LEFT(startOf, PATINDEX('%[^0-9]%', startof)-1)
FROM
(
SELECT --assumed 3 digits minimum
SUBSTRING(datapath, PATINDEX('%[0-9][0-9][0-9]%', datapath), 8000) AS startOf
FROM
(select datapath from batchinfo where LEN(datapath)>3) as bar
) foo
another words in this select statement below, instead of select datapath, i would like to run the above sql statement
SELECT reporttime,
datapath,
finalconc,
instrument
FROM batchinfo
JOIN qvalues ON batchinfo.rowid = qvalues.rowid
WHERE compound = 3 AND name = "hey"
AND batchinfo.instrument = 44
AND batchinfo.reporttime LIKE '10/%/2010%'";
SELECT reporttime,
datapath,
finalconc,
instrument
FROM
(
SELECT --assumes number not at end of string
LEFT(startOf, PATINDEX('%[^0-9]%', startof)-1) AS datapath, --correct?
rowid, instrument , reporttime
FROM
(
SELECT --assumed 3 digits minimum
SUBSTRING(datapath, PATINDEX('%[0-9][0-9][0-9]%', datapath), 8000) AS startOf,
rowid, instrument , reporttime
FROM
batchinfo --don't need LEN check. PATINDEX will do that implicitly
) foo
) batchinfo
JOIN qvalues ON batchinfo.rowid = qvalues.rowid
WHERE compound = 3 AND name = "hey"
AND batchinfo.instrument = 44
AND batchinfo.reporttime LIKE '10/%/2010%'";
If I'm reading this correctly, I would think you should be able assign your 'datapath' column in the second select to the value you're selecting in the first, and replace 'startOf' with the value you're selecting for startOf.
I think it would be something like this:
SELECT
reporttime,
'datapath' = LEFT(SUBSTRING(datapath, PATINDEX('%[0-9][0-9][0-9]%', datapath), 8000), PATINDEX('%[^0-9]%', SUBSTRING(datapath, PATINDEX('%[0-9][0-9][0-9]%', datapath), 8000))-1) ,
finalconc,
instrument
FROM batchinfo
JOIN qvalues ON batchinfo.rowid = qvalues.rowid
WHERE compound = 3 AND name = "hey"
AND batchinfo.instrument = 44
AND batchinfo.reporttime LIKE '10/%/2010%'";
Related
What I want to achieve is to have a switch case in the where clause. I want to test if this statement returns something, if it returns null, use this instead.
Sample:
SELECT [THIS_COLUMN]
FROM [THIS_TABLE]
WHERE (IF THIS [ID] RETURNS NULL THEN DO THIS SUBQUERY)
What I mean is that it will do this query first.
SELECT [THIS_COLUMN]
FROM [THIS_TABLE]
WHERE [ID] = 'SOMETHING'
If this returns NULL, do this query instead:
SELECT [THIS_COLUMN]
FROM [THIS_TABLE]
WHERE ID = (SELECT [SOMETHING] FROM [OTHER_TABLE]
WHERE [SOMETHING_SPECIFIC] = 'SOMETHING SPECIFIC')
Note that the expected results from the intended query varies from 30 rows up to 15k rows. Hope it helps.
Adding more information:
The results for this query will be used for another query but will just focus on this query.
Providing a real case scenario:
[THIS_COLUMN] is expected to have a list of VALUES.
[THIS_TABLE] contains the latest data only(let's say 1 year's worth of data) while the [OTHER_TABLE] contains the historical data.
What I want to achieve is when I query for a data that is not with in the 1 year's worth of data, IE 'SOMETHING' is not with in the 1 year scope(or in my case it returns NULL), I will use the other query where I query the 'SOMETHING_SPECIFIC'(Or may be 'SOMETHING' from the first statement makes more sense) from the historical table.
If I as reading through the lines correctly, this might work:
SELECT THIS_COLUMN
FROM dbo.THIS_TABLE TT
WHERE TT.ID = 'SOMETHING'
OR TT.ID = (SELECT OT.SOMETHING
FROM dbo.OTHER_TABLE OT
WHERE OT.SOMETHING_SPECIFIC = 'SOMETHING SPECIFIC'
AND NOT EXISTS (SELECT 1
FROM dbo.THIS_TABLE sq
WHERE sq.ID = 'SOMETHING'
AND THIS_COLUMN IS NOT NULL))
Note, however, that this could easily not be particularly performant.
You an use union all and not exists:
select this_column
from this_table
where id = 'something'
union all
select this_column
from this_table
where
not exists (select this_column from this_table where id = 'something')
and id = (select something from other_table where something_specific = 'something specific')
The first union member attempts to find rows that match the first condition, while the other one uses the subquery - the not exists prevents the second member to return something if the first member found a match.
90% of the time you can use a query-batch (i.e. a sequence of T-SQL statements) in a single SqlCommand object or SQL Server client session, so with that in-mind you could do this:
DECLARE #foo nvarchar(50) = (
SELECT
[THIS_COLUMN]
FROM
[THIS_TABLE]
WHERE
[ID] = 'SOMETHING'
);
IF #foo IS NULL
BEGIN
SELECT
[THIS_COLUMN]
FROM
[THIS_TABLE]
WHERE
[ID] = (
SELECT
[SOMETHING]
FROM
[OTHER_TABLE]
WHERE
[SOMETHING_SPECIFIC] = 'SOMETHING SPECIFIC'
)
END
ELSE
BEGIN
SELECT #foo AS [THIS_COLUMN];
END
That said, SELECT ... FROM ... WHERE x IN ( SELECT y FROM ... ) is a code-smell in a query - you probably need to rethink your solution entirely.
I have a table EmployeeTable.
If I want only that records where employeename have character of 1 to 5
will be palindrome and there also condition like total character is more then 10 then 4 to 8 if character less then 7 then 2 to 5 and if character less then 5 then all char will be checked and there that are palindrome then only display.
Examples :- neen will be display
neetan not selected
kiratitamara will be selected
I try this something on string function like FOR first case like name less then 5 character long
SELECT SUBSTRING(EmployeeName,1,5),* from EmaployeeTable where
REVERSE (SUBSTRING(EmployeeName,1,5))=SUBSTRING(EmployeeName,1,5)
I want to do that without string functions,
Can anyone help me on this?
You need at least SUBSTRING(), I have a solution like this:
(In SQL Server)
DECLARE #txt varchar(max) = 'abcba'
;WITH CTE (cNo, cChar) AS (
SELECT 1, SUBSTRING(#txt, 1, 1)
UNION ALL
SELECT cNo + 1, SUBSTRING(#txt, cNo + 1, 1)
FROM CTE
WHERE SUBSTRING(#txt, cNo + 1, 1) <> ''
)
SELECT COUNT(*)
FROM (
SELECT *, ROW_NUMBER() OVER (ORDER BY cNo DESC) as cRevNo
FROM CTE t1 CROSS JOIN
(SELECT Max(cNo) AS strLength FROM CTE) t2) dt
WHERE
dt.cNo <= dt.strLength / 2
AND
dt.cChar <> (SELECT dti.cChar FROM CTE dti WHERE dti.cNo = cRevNo)
The result will shows the count of differences and 0 means no differences.
Note :
Current solution is Non-Case-Sensitive for change it to a Case-Sensitive you need to check the strings in a case-sensitive collation like Latin1_General_BIN
You can use this solution as a SVF or something like that.
I dont realy understand why you dont want to use string functions in your query, but here is one solution. Compute everything beforehand:
Add Column:
ALTER TABLE EmployeeTable
ADD SubString AS
SUBSTRING(EmployeeName,
(
CASE WHEN LEN(EmployeeName)>10
THEN 4
WHEN LEN(EmployeeName)>7
THEN 2
ELSE 1 END
)
,
(
CASE WHEN LEN(EmployeeName)>10
THEN 8
WHEN LEN(EmployeeName)>7
THEN 5
ELSE 5 END
)
PERSISTED
GO
ALTER TABLE EmployeeTable
ADD Palindrome AS
REVERSE(SUBSTRING(EmployeeName,
(
CASE WHEN LEN(EmployeeName)>10
THEN 4
WHEN LEN(EmployeeName)>7
THEN 2
ELSE 1 END
)
,
(
CASE WHEN LEN(EmployeeName)>10
THEN 8
WHEN LEN(EmployeeName)>7
THEN 5
ELSE 5 END
)) PERSISTED
GO
Then your query will looks like:
SELECT * from EmaployeeTable
where Palindrome = SubString
BUT!
This is not a good idea. Please tell us, why you dont want to use string functios.
You could do it building a list of palindrome words using a recursive query that generates palindrome words till a length o n characters and then selects employees with the name matching a palindrome word. This may be a really inefficient way, but it does the trick
This is a sample query for Oracle, PostgreSQL should support this feature as well with little differences on syntax. I don't know about other RDBMS.
with EmployeeTable AS (
SELECT 'ADA' AS employeename
FROM DUAL
UNION ALL
SELECT 'IDA' AS employeename
FROM DUAL
UNION ALL
SELECT 'JACK' AS employeename
FROM DUAL
), letters as (
select chr(ascii('A') + rownum - 1) as letter
from dual
connect by ascii('A') + rownum - 1 <= ascii('Z')
), palindromes(word, len ) as (
SELECT WORD, LEN
FROM (
select CAST(NULL AS VARCHAR2(100)) as word, 0 as len
from DUAL
union all
select letter as word, 1 as len
from letters
)
union all
select l.letter||p.word||l.letter AS WORD, len + 1 AS LEN
from palindromes p
cross join letters l
where len <= 4
)
SEARCH BREADTH FIRST BY word SET order1
CYCLE word SET is_cycle TO 'Y' DEFAULT 'N'
select *
from EmployeeTable
WHERE employeename IN (
SELECT WORD
FROM palindromes
)
DECLARE #cPalindrome VARCHAR(100) = 'SUBI NO ONIBUS'
SET #cPalindrome = REPLACE(#cPalindrome, ' ', '')
;WITH tPalindromo (iNo) AS (
SELECT 1
WHERE SUBSTRING(#cPalindrome, 1, 1) = SUBSTRING(#cPalindrome, LEN(#cPalindrome), 1)
UNION ALL
SELECT iNo + 1
FROM tPalindromo
WHERE SUBSTRING(#cPalindrome, iNo + 1, 1) = SUBSTRING(#cPalindrome, LEN(#cPalindrome) - iNo, 1)
AND LEN(#cPalindrome) > iNo
)
SELECT IIF(MAX(iNo) = LEN(#cPalindrome), 'PALINDROME', 'NOT PALINDROME')
FROM tPalindromo
I would like my SQL query to return a row even if there is no row matching in my IN clause.
For exemple this query:
SELECT id, foo
FROM table
WHERE id IN (0, 1, 2, 3)
would return:
id|foo
0|bar
1|bar
2|bar
3|null
But instead I have (because no row with id 3):
id|foo
0|bar
1|bar
2|bar
I have been able to find this trick:
SELECT tmpTable.id, table.bar
FROM (
SELECT 0 as id
UNION SELECT 1
UNION SELECT 2
UNION SELECT 3
) tmpTable
LEFT JOIN
(
SELECT table.foo, table.id
FROM table
WHERE table.id IN (0, 1, 2, 3)
) table
on table.id = tmpTable.id
Is there a better way?
Bonus: How to make it work with myBatis's list variable?
overslacked is right. Most SQL developers use an auxiliary table that stores integers (and one that stores dates). This is outlined in an entire chapter of Joe Celko's "SQL for Smarties".
Example:
CREATE TABLE numeri ( numero INTEGER PRIMARY KEY )
DECLARE #x INTEGER
SET #x = 0
WHILE #x < 1000
BEGIN
INSERT INTO numeri ( numero ) VALUES ( #x )
SET #x = #x + 1
END
SELECT
numero AS id,
foo
FROM
numeri
LEFT OUTER JOIN my_table
ON my_table.id = numero
WHERE
numero BETWEEN 0 AND 3
Main Goal of Programming minimal code high performance no need this things just remove id 3 from in clause
What about just saying:
SELECT id, foo
FROM table
WHERE id >= 0 AND <= 3
I have an issue where in my data I will have a record returned where a column value will look like
-- query
Select col1 from myTable where id = 23
-- result of col1
111, 104, 34, 45
I want to feed these values to an in clause. So far I have tried:
-- Query 2 -- try 1
Select * from mytableTwo
where myfield in (
SELECT col1
from myTable where id = 23)
-- Query 2 -- try 2
Select * from mytableTwo
where myfield in (
SELECT '''' +
Replace(col1, ',', ''',''') + ''''
from myTable where id = 23)
-- query 2 test -- This works and will return data, so I verify here that data exists
Select * from mytableTwo
where myfield in ('111', '104', '34', '45')
Why aren't query 2 try 1 or 2 working?
You don't want an in clause. You want to use like:
select *
from myTableTwo t2
where exists (select 1
from myTable t
where id = 23 and
', '+t.col1+', ' like '%, '+t2.myfield+', %'
);
This uses like for the comparison in the list. It uses a subquery for the value. You could also phrase this as a join by doing:
select t2.*
from myTableTwo t2 join
myTable t
on t.id = 23 and
', '+t.col1+', ' like '%, '+t2.myfield+', %';
However, this could multiply the number of rows in the output if there is more than one row with id = 23 in myTable.
If you observe closely, Query 2 -- try 1 & Query 2 -- try 2 are considered as single value.
like this :
WHERE myfield in ('111, 104, 34, 45')
which is not same as :
WHERE myfield in ('111', '104', '34', '45')
So, If you intend to filter myTable rows from MyTableTwo, you need to extract the values of fields column data to a table variable/table valued function and filter the data.
I have created a table valued function which takes comma seperated string and returns a table value.
you can refer here T-SQL : Comma separated values to table
Final code to filter the data :
DECLARE #filteredIds VARCHAR(100)
-- Get the filter data
SELECT #filteredIds = col1
FROM myTable WHERE id = 23
-- TODO : Get the script for [dbo].[GetDelimitedStringToTable]
-- from the given link and execute before this
SELECT *
FROM mytableTwo T
CROSS APPLY [dbo].[GetDelimitedStringToTable] ( #filteredIds, ',') F
WHERE T.myfield = F.Value
Please let me know If this helps you!
I suppose col is a character type, whose result would be like like '111, 104, 34, 45'. If this is your situation, it's not the best of the world (denormalized database), but you can still relate these tables by using character operators like LIKE or CHARINDEX. The only gotcha is to convert the numeric column to character -- the default conversion between character and numeric is numeric and it will cause a conversion error.
Since #Gordon, responded using LIKE, I present a solution using CHARINDEX:
SELECT *
FROM mytableTwo tb2
WHERE EXISTS (
SELECT 'x'
FROM myTable tb1
WHERE tb1.id = 23
AND CHARINDEX(CONVERT(VARCHAR(20), tb2.myfield), tb1.col1) > 0
)
I have a sql query that I run against a sql server database eg.
SELECT * FROM MyTable WHERE Id = 2
This may return a number of records or may return none. If it returns none, I would like to alter my sql query to return a default record, is this possible and if so, how? If records are returned, the default record should not be returned. I cannot update the data so will need to alter the sql query for this.
Another way (you would get an empty initial rowset returned);
SELECT * FROM MyTable WHERE Id = 2
IF (##ROWCOUNT = 0)
SELECT ...
SELECT TOP 1 * FROM (
SELECT ID,1 as Flag FROM MyTable WHERE Id = 2
UNION ALL
SELECT 1,2
) qry
ORDER BY qry.Flag ASC
You can have a look to this post. It is similar to what you are asking
Return a value if no rows are found SQL
I hope that it can guide you to the correct path.
if not exists (SELECT top 1 * FROM mytable WHERE id = 2)
select * from mytable where id= 'whatever_the_default_id_is'
else
select * from mytable where id = 2
If you have to return whole rows of data (and not just a single column) and you have to create a single SQL query then do this:
Left join actual table to defaults single-row table
select
coalesce(a.col1, d.col1) as col1,
coalesce(a.col2, d.col2) as col2,
...
from (
-- your defaults record
select
default1 as col1,
default2 as col2,
...) as d
left join actual as a
on ((1 = 1) /* or any actual table "where" conditions */)
The query need to return the same number of fields, so you shouldn't do a SELECT * FROM but a SELECT value FROM if you want to return a default value.
With that in mind
SELECT value FROM MyTable WHERE Id = 2
UNION
SELECT CASE (SELECT count(*) FROM MyTable WHERE Id = 2)
WHEN 0 THEN 'defaultvalue'
END