how to create variable in query sqlite - sqlite

I want to use variable in my query for sqlite but I don't know how do it?
my query is it :
/*I want to declare my variable in here and use this variable query*/
/*declare vaiable*/SELECT direct_station.iddirect_station,station.name,line.color FROM direct_station JOIN
direction ON direction.iddirection = direct_station.iddirection JOIN
station ON station.idstation = direction.laststation JOIN line ON line.idline = direction.line WHERE direct_station.idstation = /*put variable*/
Explain :
my friends I want execute one query but this query have two part :
first part I want to get several value like this {178,180,200,300}. I got this from this query :
SELECT direct_station.iddirect_station FROM direct_station WHERE direct_station.idstation = 98
and second part I want to use any these values to this query by one variable :
SELECT * FROM stations_view WHERE iddirection = %d
now I want to get any value from second query that joined to first query.

I think that the solution could be to create a Table for your variable where you are going to store the variable's value and from where you can retrieve the value when needed.
INSERT INTO VariableTable (Variable) VALUES ('x');
SELECT * FROM TableName WHERE ColumnName = (SELECT Variable FROM VariableTable);

Related

Query SQLite using uuid returns nothing

I'm querying a SQLite db file using the id column, which is UNIQUEIDENTIFIER type.
The two commands are :
SELECT * FROM scanned_images WHERE id = cast('5D878B98-71B2-4DEE-BA43-61D11C8EA497' as uniqueidentifier)
or
SELECT * FROM scanned_images WHERE id = '5D878B98-71B2-4DEE-BA43-61D11C8EA497'
However, the above commands both returned nothing.
I also tried:
SELECT * FROM scanned_images WHERE rowid = 1
this command returns the correct data.
There is no uniqueidentifier data type in SQLite.
According to the rules of type affinity described here in 3.1. Determination Of Column Affinity, the column's affinity is numeric.
All that this expression does:
cast('5D878B98-71B2-4DEE-BA43-61D11C8EA497' as uniqueidentifier)
is return 5.
You should have defined the column's data type as TEXT, because you have to treat it like TEXT and write the condition:
WHERE id = '5D878B98-71B2-4DEE-BA43-61D11C8EA497'
or:
WHERE id = '(5D878B98-71B2-4DEE-BA43-61D11C8EA497)'
if as shown in the image it contains surrounding parentheses.

Update row with value from next row sqlite

I have the following columns in a SQLite DB.
id,ts,origin,product,bid,ask,nextts
1,2016-10-18 20:20:54.733,SourceA,Dow,1.09812,1.0982,
2,2016-10-18 20:20:55.093,SourceB,Oil,7010.5,7011.5,
3,2016-10-18 20:20:55.149,SourceA,Dow,18159.0,18161.0,
How can I populate the 'next timestamp' column (nextts) with the next timestamp for the same product (ts), from the same source? I've been trying the following, but I can't seem to put a subquery in an UPDATE statement.
UPDATE TEST a SET nextts = (select ts
from TEST b
where b.id> a.id and a.origin = b.origin and a.product = b.product
order by id asc limit 1);
If I call this, I can display it, but I haven't found a way of updating the value yet.
select a.*,
(select ts
from TEST b
where b.id> a.id and a.origin = b.origin and a.product = b.product
order by id asc limit 1) as nextts
from TEST a
order by origin, a.id;
The problem is that you're using table alias for table in UPDATE statement, which is not allowed. You can skip alias from there and use unaliased (but table-name prefixed) reference to its columns (while keeping aliased references for the SELECT), like this:
UPDATE TEST
SET nextts = (
SELECT b.ts
FROM TEST b
WHERE b.id > TEST.id AND
TEST.origin = b.origin AND
TEST.product = b.product
ORDER BY b.id ASC
LIMIT 1
);
Prefixing unaliased column references with the table name is necessary for SQLite to identify that you're referencing to unaliased table. Otherwise the id column whould be understood as the id from the closest[*] possible data source, in which case it's the aliased table (as b alias), while we're interested in the unaliased table, therefore we need to explicitly tell SQLite that.
[*] Closest data source is the one listed in the same query, or parent query, or parent's parent query, etc. SQLite is looking for the first data source (going from inner part to the outside) in the query hierarchy that defines this column.

Ordering SQL Server results by IN clause

I have a stored procedure which uses the IN clause. In my ASP.NET application, I have a multiline textbox that supplies values to the stored procedure. I want to be able to order by the values as they were entered in the textbox. I found out how to do this easily in mySQL (using FIELD function), but not a SQL Server equivalent.
So my query looks like:
Select * from myTable where item in #item
So I would be passing in values from my application like '113113','112112','114114' (in an arbitrary order). I want to order the results by that list.
Would a CASE statement be feasible? I wouldn't know how many items are coming in the textbox data.
How are you parameterising the IN clause?
As you are on SQL Server 2008 I would pass in a Table Valued Parameter with two columns item and sort_order and join on that instead. Then you can just add an ORDER BY sort_order onto the end.
From KM's comment above...
I know you didn't state it is comma seperated, but if it was a CSV or even if you have it space seperated you could do the following.
DECLARE #SomeTest varchar(100) --used to hold your values
SET #SomeTest = (SELECT '68,72,103') --just some test data
SELECT
LoginID --change to your column names
FROM
Login --change to your source table name
INNER JOIN
( SELECT
*
FROM fn_IntegerInList(#SomeTest)
) n
ON
n.InListID = Login.LoginID
ORDER BY
n.SortOrder
And then create fn_IntegerInList():
CREATE FUNCTION [dbo].[fn_IntegerInList] (#InListString ntext)
RETURNS #tblINList TABLE (InListID int, SortOrder int)
AS
BEGIN
declare #length int
declare #startpos int
declare #ctr int
declare #val nvarchar(50)
declare #subs nvarchar(50)
declare #sort int
set #sort=1
set #startpos = 1
set #ctr = 1
select #length = datalength(#InListString)
while (#ctr <= #length)
begin
select #val = substring(#InListString,#ctr,1)
if #val = N','
begin
select #subs = substring(#InListString,#startpos,#ctr-#startpos)
insert into #tblINList values (#subs, #sort)
set #startpos = #ctr+1
end
if #ctr = #length
begin
select #subs = substring(#InListString,#startpos,#ctr-#startpos)
insert into #tblINList values (#subs, #sort)
end
set #ctr = #ctr +1
set #sort = #sort + 1
end
RETURN
END
This way your function creates a table that holds a sort order namely, SortOrder and the ID or number you are passing in. You can of course modify this so that you are looking for space rather then , values. Otherwise Martin has the right idea in his answer. Please note in my example I am using one of my tables, so you will need to change the name Login to whatever you are dealing with.
the same way you concatenate ('113113','112112','114114') to pass to the sql sentence in the where clausule you can concatenate
order by
case item
when '113113' then 1
when '112112' then 2
when '114114' then 3
end
to pass to your order by clausule

MySQL Changing Order Depending On Contents of a Column

I have a MySQL table Page with 2 columns: PageID and OrderByMethod.
I also then have a Data table with lots of columns including PageID (the Page the data is on), DataName, and DataDate.
I want OrderByMethod to have one of three entries: Most Recent Data First, Most Recent Data Last, and Alphabetically.
Is there a way for me to tack an "ORDER BY" clause to the end of this query that will vary its ordering method based on the contents of the "OrderByMethod" column? For example, in this query, I would want to have the ORDER BY clause contain whatever ordering rule is stored in Page 1's OrderByMethod column.
GET * FROM `Data` WHERE `Data`.`PageID`=1 ORDER BY xxxxxx;
Maybe a SELECT clause in the ORDER BY clause? I'm not sure how that would work though.
Thanks!
select Data.*
from Data
inner join Page on (Data.PageID=Page.PageID)
where Data.PageID=1
order by
if(Page.OrderByMethod='Most Recent Data First', now()-DataDate,
if(Page.OrderByMethod='Most Recent Data Last', DataDate-now(), DataName)
);
You can probably do this with the IF syntax to generate a column that you can then order by.
SELECT *, IF(Page.OrderBy = 'Alphabetically', Data.DataName, IF(Page.OrderBy = 'Most Recent Data First', NOW() - Data.DataDate, Data.DataDate - NOW())) AS OrderColumn
FROM Data
INNER JOIN Page ON Data.PageID = Page.PageID
WHERE Page.PageID = 1
ORDER BY OrderColumn
The direction of the ordering is determined in the calculation of the data instead of specifying a direction in the ORDER BY
Can you just append the order by clause to the select statement and rebind the table on postback?
If you want to use the content of the column in Page table as an expression in ORDER BY you have to do it using prepared statements. Let say, you store in OrderByMethod something like "field1 DESC, field2 ASC" and you want this string to be used as it is:
SET #order_by =(SELECT OrderByMethod FROM Page WHERE id = [value]);
SET #qr = CONCAT(your original query,' ORDER BY ', #order_by);
PREPARE stmt FROM #qr;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
If you want the result set to be sorted based on the value of OrderByMethod , you can use IF as it was already mentioned by others, or CASE :
...
ORDER BY
CASE OrderByMethod
WHEN 'val1' THEN field_name1
WHEN 'val2' THEN field_name2
....etc
END

In query in SQLite

"IN" query is not working. Please guide me if i am wrong.
KaizenResultsInformationTable is MasterTable having field "recordinfo", this field contains Child table Ids as string.
kaizenResultsRecordInformationTable is Childtable having field "recordId".
I have to match records of child.
Query:
select recordinfo from KaizenResultsInformationTable
Output: ;0;1;2;3;4;5;6;7;8;9;10
Query:
select substr(replace(recordinfo,';','","'),3,length(recordinfo))
from KaizenResultsInformationTable`
Output: "0","1","2","3","4","5"
This query is not working:
select * from kaizenResultsRecordInformationTable
where substr(recordid,0,2) in (
select substr(replace(recordinfo,';','","'),3,length(recordinfo))
from KaizenResultsInformationTable
)
This query is working:
select * from kaizenResultsRecordInformationTable
where substr(recordid,0,2) in ("0","1","2","3","4","5")
You can't use in like that. In your second query, you are passing in a single string containing a comma-separated list of values.
It is better to represent a list of IDs as one record for each value.
Also, I'm not sure why you are taking a substring of your recordid. You should usually be storing one value per column.
However, if you can't change the schema, you can use string matching with 'like' instead of 'in'. Something like this should work:
select a.* from kaizenResultsRecordInformationTable a
join KaizenResultsInformationTable b
on (';'+b.recordinfo+';') LIKE ('%;'+trim(substr(recordid,0,2))+';%')
So if your recordinfo looks like 1;2;3;4;5;6, and your substr(recordid,0,2) looks like 1, this will include that row if ";1;2;3;4;5;6;" LIKE "%;1;%", which is true.

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