I was trying to write a simple FluxQL Query in Grafana Dashboard that uses a variable
m1(of type constant)(which contains the name of the measurement)
I created the variable m1 in grafana dashboard variables
m1 = my-measurement
and tried to run the following queries but non of them worked and they either say expression request error or No Data)
i.e
SELECT count("fails") FROM "/^${m1:raw}$/"
SELECT count("fails") FROM "/^${m1}$/"
SELECT count("fails") FROM $m1" (expression request error)
SELECT count("fails") FROM "$m1"
SELECT count("fails") FROM "${m1}"
The only query worked was without dashboard variables
SELECT count("fails") FROM "my-measurement"
How can I use the variables to work for that query.
On the similar ground I tried to make a custom variable(myVar) for which we take integer input values from user and on that basis where clause should work, but same error occurs either no data or expression request error
What I tried was
SELECT count(*) from "my-measurement-2" WHERE ("value" > $myVar)
How should I solve these issues?Please help
You may have a problem with
1.) syntax
SELECT count("fails")
FROM "${m1:raw}"
2.) data
You may correct query syntax, but query can be very inefficient. Query execution may need a lot of time - so it's better to have timefilter, which will use selected dashboard time range (make sure you have some data in that time range)
SELECT count("fails")
FROM "${m1:raw}"
WHERE $timeFilter
3.) Grafana panel configuration
Make sure you are using suitable panel - for query above Stat panel is a good option (that query returns only single value, not timeseries, so time series panel types may have a problem with that).
Generally, use query inspector to see how are variables interpolated - there can be "magic", which is not obvious - e.g. quotes which are added around numeric variables, so then it is string filtering and not numeric filtering on the InfluxDB level.
I have a following issue:
I need to calculate difference between consecutive points where some arbitrary ID is equal. The following:
SELECT difference(value_field) FROM mesurementName WHERE "IdField" = '10'
Works, returns difference between each consecutive point with IdField BUT IdField is lost (only time is propagated to query result). In my case time is not unique (i.e. measurement may contain many points with same timestamp, but different IdField). So I tried:
SELECT difference(value_field), IdField FROM mesurementName WHERE "IdField" = '10'
which yields:
error parsing query: mixing aggregate and non-aggregate queries is not supported!!
My next attempt was using sub-query:
SELECT IdField, diff
FROM (
SELECT
difference(flow_val) as diff
FROM
mesurementA
WHERE "IdField" = '10'
)
Which resulted in always null value in IdField.
I'd like to ask you for help or suggestion how to solve issue. By the way, we are using InfluxDB 1.3, which is not supporting JOIN anymore
If anyone would stuck as I was, then solution is following:
SELECT difference(value_field) FROM mesurementName GROUP BY "IdField"
Above somehow implicitly add "IdField" to result series and is propagated to resulting measurements with INTO clause
I am working on an asp.net mvc web application, and I am using Sql server 2008 R2 + Entity framework.
Now on the sql server I have added a unique index on any column that might be ordered by . for example I have created a unique index on the Sql server on the Tag colum and I have defined that the sort order for the index to be Ascending. Now I have some queries inside my application that order the tag ascending while other queries order the Tag descending, as follow:-
LatestTechnology = tms.Technologies.Where(a=> !a.IsDeleted && a.IsCompleted).OrderByDescending(a => a.Tag).Take(pagesize).ToList(),;
TechnologyList = tms.Technologies.Where(a=> !a.IsDeleted && a.IsCompleted).OrderBy (a => a.Tag).Take(pagesize).ToList();
So my question is whether the two OrderByDescending(a => a.Tag). & OrderBy(a => a.Tag), can benefit from the asending unique index on the sql server on the Tag colum ? or I should define two unique indexes on the sql server one with ascending sort order while the other index with decedning sort order ?
THanks
EDIT
the following query :-
LatestTechnology = tms.Technologies.Where(a=> !a.IsDeleted && a.IsCompleted).OrderByDescending(a => a.Tag).Take(pagesize).ToList();
will generate the following sql statement as mentioned by the sql server profiler :-
SELECT TOP (15)
[Extent1].[TechnologyID] AS [TechnologyID],
[Extent1].[Tag] AS [Tag],
[Extent1].[IsDeleted] AS [IsDeleted],
[Extent1].[timestamp] AS [timestamp],
[Extent1].[TypeID] AS [TypeID],
[Extent1].[StartDate] AS [StartDate],
[Extent1].[IT360ID] AS [IT360ID],
[Extent1].[IsCompleted] AS [IsCompleted]
FROM [dbo].[Technology] AS [Extent1]
WHERE ([Extent1].[IsDeleted] <> cast(1 as bit)) AND ([Extent1].[IsCompleted] = 1)
ORDER BY [Extent1].[Tag] DESC
To answer your question:
So my question is whether the two OrderByDescending(a => a.Tag). &
OrderBy(a => a.Tag), can benefit from the asending unique index on the
sql server on the Tag colum ?
Yes, SQL Server can read an index in both directions: as in index definition or in the exact opposite direction.
However, from your intro I suspect that you still have a wrong impression how indexing works for order by. If you have both, a where clause and an order by clause, you must make sure to have a single index that covers both clauses! It does not help to have on index for the where clause (like on isDeleted and isCompleted — whatever that is in your example) and another index on tag. You need to have a single index that first has the columns of the where clause followed by the columns of the order by clause (multi-column index).
It can be tricky to make it work correctly, but it's worth the effort especially if your are only fetching the first few rows (like in your example).
If it doesn't work out right away, please have a look at this:
http://use-the-index-luke.com/sql/sorting-grouping/indexed-order-by
It is generally best to show the actual SQL query—not the .NET source code—when asking for performance advice. Then I could tell you which index to create exactly. At the moment I'm unsure about isDeleted and isCompleted — are these table columns or expressions that evaluate upon other columns?
EDIT (after you added the SQL query)
There are two ways to make your query work as indexed top-n query:
http://sqlfiddle.com/#!6/260fb/4
The first option is a regular index on the columns from the where clause followed by those from the order by clause. However, as you query uses this filter IsDeleted <> cast(1 as bit) it cannot use the index in a order-preserving way. If, however, you re-phrase the query so that it reads like this IsDeleted = cast(0 as bit) then it works. Please look at the fiddle, I've prepared everything there. Yes, SQL Server could be smart enough to know that, but it seems like it isn't.
I don't know how to tweak EF to produce the query in the above described way, sorry.
However, there is a second option using a so called filtered index — that is an index that only contains a sub-set of the table rows. It's also in the SQL Fiddle. Here it is important that you add the where clause to the index definition in the very same way as it appears in your query.
In both ways it still works if you change DESC to ASC.
The important part is that the execution plan doesn't show a sort operation. You can also verify this in SQL Fiddle (click on 'View execution plan').
I am trying to do something like this:
merge MembershipTEST as T
using (select OrganisationID, Name From MembershipPending) as S
on T.OrganisationID = S.OrganisationID
and T.Name = S.Name
when not matched then
insert (MembershipID,OrganisationID, Name)
values(
(EXEC [dbo].[spGetNextIntKeyByTableName]
#PKColName = 'MembershipID',#TableName = 'FWBMembership'),
S.OrganisationID,
S.Name );
Bascially the identitykey is from a sp
Is it possible?
Update 1: Answer is NO
read the online doc http://msdn.microsoft.com/en-us/library/bb510625%28v=sql.105%29.aspx
VALUES ( values_list) Is a comma-separated list of constants,
variables, or expressions that return values to insert into the target
table. Expressions cannot contain an EXECUTE statement.
Build an SSIS package. Just create a new Data Flow task. Use two OLEDB sources make one of them execute the stored procedure and the other one select from the table you are looking to MERGE with. Make sure they are both ordered by the same thing. Go into advanced settings for each OLEDB source and set is sorted to true and then set the sort values for the items you are ORDERing BY. Then move both data flows to to a MERGE JOIN. Then send the Data flow to a Conditional Split and set as INSULL(OrganisationID). Use the resulting data flow to go to an OLEDB destination.
Sorry for the lack of visuals I will add them later when I'm on lunch hour to busy to add them now.
INFORMIX-SQL 7.3 Perform Screens:
According to documentation, in an "after editadd editupdate of table" control block, its instructions are executed before the row is added or updated to the table, whereas in an "after add update of table" control block, its instructions are executed after the row has been added or updated to the table. Supposedly, this would mean that any instructions which would alter values of field-tags linked to table.columns would not be committed to the table, but field-tags linked to displayonly fields will change?
However, when using "after add update of table", I placed instructions which alter values for field-tags linked to table.columns and their displayed and committed values also changed! I would have thought that an "after add update of table" would only alter displayonly fields.
TABLES
customer
transaction
branch
interest
dates
ATTRIBUTES
[...]
q = transaction.trx_type, INCLUDE=("E","C","V","P","T"), ...;
tb = transaction.trx_int_table,
LOOKUP f1 = ta_days1_f,
t1 = ta_days1_t,
i1 = ta_int1,
[...]
JOINING *interest.int_table, ...;
[...]
INSTRUCTIONS
customer MASTER OF transaction
transaction MASTER OF customer
delimiters ". ";
AFTER QUERY DISPLAY ADD UPDATE OF transaction
if z = "E" then let q = "E"
if z = "C" then let q = "C"
if z = "1" then let q = "E"
[...]
END
Is 'z' a column in the transaction table?
Is the trouble that the value in 'z' is causing a change in the value of 'q' (aka transaction.trx_type), and the modified value is being stored in the database?
Is the value in 'z' part of the transaction table?
Have you verified that the value in the DB is indeed changed - using the Query Language option or a simple (default) form?
It might look as if it is because the instruction is also used AFTER DISPLAY, so when the values are retrieved from the DB, the value displayed in 'q' would be the mapped values corresponding to the value stored in 'z'. You would have to inspect the raw data to hide that mapping.
If this is not the problem, please:
Amend the question to show where 'z' comes from.
Also describe exactly what you do and see.
Confirm that the data in the database, as opposed to on the screen, is amended.
Please can you see whether this table plus form behaves the same for you as it does for me?
Table Transaction
CREATE TABLE TRANSACTION
(
trx_id SERIAL NOT NULL,
trx_type CHAR(1) NOT NULL,
trx_last_type CHAR(1) NOT NULL,
trx_int_table INTEGER NOT NULL
);
Form
DATABASE stores
SCREEN SIZE 24 BY 80
{
trx_id [f000]
trx_type [q]
trx_last_type [z]
trx_int_table [f001 ]
}
END
TABLES
transaction
ATTRIBUTES
f000 = transaction.trx_id;
q = transaction.trx_type, UPSHIFT, AUTONEXT,
INCLUDE=("E","C","V","P","T");
z = transaction.trx_last_type, UPSHIFT, AUTONEXT,
INCLUDE=("E","C","V","P","T","1");
f001 = transaction.trx_int_table;
INSTRUCTIONS
AFTER ADD UPDATE DISPLAY QUERY OF transaction
IF z = "E" THEN LET q = "E"
IF z = "C" THEN LET q = "C"
IF z = "1" THEN LET q = "E"
END
Experiments
[The parenthesized number is automatically generated by IDS/Perform.]
Add a row with data (1), V, E, 23.
Observe that the display is: 1, E, E, 23.
Exit the form.
Observe that the data in the table is: 1, V, E, 23.
Reenter the form and query the data.
Update the data to: (1), T, T, 37.
Observe that the display is: 1, T, T, 37.
Exit the form.
Observe that the data in the table is: 1, T, T, 37.
Reenter the form and query the data.
Update the data to: (1), P, 1, 49
Observe that the display is: 1, E, 1, 49.
Exit the form.
Observe that the data in the table is: 1, P, 1, 49.
Reenter the form and query the data.
Observe that the display is: 1, E, 1, 49.
Choose 'Update', and observe that the display changes to: 1, P, 1, 49.
I did the 'Observe that the data in the table is' steps using:
sqlcmd -d stores -e 'select * from transaction'
This generated lines like these (reflecting different runs):
1|V|E|23
1|P|1|49
That is my SQLCMD program, not Microsoft's upstart of the same name. You can do more or less the same thing with DB-Access, except it is noisier (13 extraneous lines of output) and you would be best off writing the SELECT statement in a file and providing that as an argument:
$ echo "select * from transaction" > check.sql
$ dbaccess stores check
Database selected.
trx_id trx_type trx_last_type trx_int_table
1 P 1 49
1 row(s) retrieved.
Database closed.
$
Conclusions
This is what I observed on Solaris 10 (SPARC) using ISQL 7.50.FC1; it matches what the manual describes, and is also what I suggested in the original part of the answer might be the trouble - what you see on the form is not what is in the database (because of the INSTRUCTIONS section).
Do you see something different? If so, then there could be a bug in ISQL that has been fixed since. Technically, ISQL 7.30 is out of support, I believe. Can you upgrade to a more recent version than that? (I'm not sure whether 7.32 is still supported, but you should really upgrade to 7.50; the current release is 7.50.FC4.)
Transcribing commentary before deleting it:
Up to a point, it is good that you replicate my results. The bad news is that in the bigger form we have different behaviour. I hope that ISQL validates all limits - things like number of columns etc. However, there is a chance that they are not properly validated, given the bug, or maybe there is a separate problem that only shows with the larger form. So, you need to ensure you have a supported version of the product and that the problem reproduces in it. Ideally, you will have a smaller version of the table (or, at least, of the form) that shows the problem, and maybe a still smaller (but not quite as small as my example) version that shows the absence of the problem.
With the test case (table schema and Perform screen that shows the problem) in hand, you can then go to IBM Tech Support with "Look - this works correctly when the form is small; and look, it works incorrectly when the form is large". The bug should then be trackable. You will need to include instructions on how to reproduce the bug similar to those I gave you. And there is no problem with running two forms - one simple and one more complex and displaying the bug - in parallel to show how the data is stored vs displayed. You could describe the steps in terms of 'Form A' and 'Form B', with Form A being Absolutely OK and Form B being Believed to be Buggy. So, add a record with certain values in Form B; show what is displayed in Form B after; show what is stored in the database in Form A after too; show that they are not different when they should be.
Please bear in mind that those who will be fixing the issue have less experience with the product than either you or me - so keep it as simple as possible. Remove as many attributes as you can; leave comments to identify data types etc.