Is there any way to delete columns of an influx timeseries as we have accidentally injected data using the wrong data type (int instead of float).
Or to change the type of data instead.
Unfortunately, there is no way to delete a "column" (i.e. a tag or a field) from an Influx measurement so far. Here's the feature request for that but there is no ETA yet.
Three workarounds:
use SELECT INTO to copy the desirable data into a different measurement, excluding the undesirable "columns". e.g.:
SELECT desirableTag1, desirableTag2, desirableField1, desirableField2 INTO new_measurement FROM measurement
use CAST operations to "change the data type" from float to int. e.g.:
SELECT desirableTag1, desirableTag2, desirableField1, desirableField2, undesiredableTag3::integer, undesiredableField3::integer INTO new_measurement FROM measurement
"Update" the data with insert statement, which will overwrite the data with the same timestamp, same tags, same field keys. Keep all other things equal, except that the "columns" that you would like to update. To make the data in integer data type, remember to put a trailing i on the number. Example: 42i. e.g.:
insert measurement,desirableTag1=v1 desirableField1=fv1,desirableField2=fv2,undesirableField1=someValueA-i 1505799797664800000
insert measurement,desirableTag1=v21 desirableField1=fv21,desirableField2=fv22,undesirableField1=someValueB-i 1505799797664800000
Related
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 Line Protocol like this:
Measurement1,Valuetype=Act_value,metric=Max,dt=Int value=200i 1553537228984000000
Measurement1,Valuetype=Act_value,metric=Lower_bound,dt=Int value=25i 1553537228987000000
Measurement1,Valuetype=Act_value,metric=Min,dt=Int value=10i 1553537228994000000
Measurement1,Valuetype=Act_value,metric=Upper_limit,dt=Int value=222i 1553537228997000000
Measurement1,Valuetype=Act_value,metric=Lower_limit,dt=Int value=0i 1553537229004000000
Measurement1,Valuetype=Act_value,metric=Simulation,dt=bool value=False 1553537229007000000
Measurement1,Valuetype=Act_value,metric=Value,dt=Int value=69i 1553537229014000000
Measurement1,Valuetype=Act_value,metric=Percentage,dt=Int value=31i 1553537229017000000
Measurement1,Valuetype=Set_value,metric=Upper_limit,dt=Int value=222i 1553537229024000000
Measurement1,Valuetype=Set_value,metric=Lower_limit,dt=Int value=0i 1553537229028000000
Measurement1,Valuetype=Set_value,metric=Unit,dt=string value="Kelvin" 1553537229035000000
Measurement1,Valuetype=Set_value,metric=Value,dt=Int value=222i 1553537229038000000
Measurement1,Valuetype=Set_value,metric=Percentage,dt=Int value=0i 1553537229045000000
I need to insert multiple Lines at once. The issue is likely that I insert integers, booleans and strings into the same table. It worked when I created measurements like, e.g. Measurement1_Int,Measurement1_bool,Measurement1_string. In the above configuration I get an error.
I have the following questions:
Is there any way to save values of different (data-)types to one
table/measurement?
If yes how do I need to adjust my Line Protocol?
Would it work I write the three datatypes seperately but still in the same table?
If you can afford to assign the same timestamp to all metrics within measurement datapoint the best variant would be to use metric name a field name in influxdb record:
Measurement1,Valuetype=Act_value Max=200i,Lower_bound=25i,Min=10i,Upper_limit=222i,Lower_limit=0i,Simulation=False,Value=69i,Percentage=31i 1553537228984000000
Otherwise you can still use metric name as field name but missing fields for each timestamp will have null values:
Measurement1,Valuetype=Set_value Upper_limit=222i 1553537229024000000
Measurement1,Valuetype=Set_value Lower_limit=0i 1553537229028000000
Measurement1,Valuetype=Set_value Unit="Kelvin" 1553537229035000000
Measurement1,Valuetype=Set_value Value=222i 1553537229038000000
Measurement1,Valuetype=Set_value Percentage=0i 1553537229045000000
Using Delphi 10.2, SQLite and Teecharts. My SQLite database has two fields, created with:
CREATE TABLE HistoryRuntime ('DayTime' DateTime, Device1 INTEGER DEFAULT (0));
I access the table using a TFDQuery called qryGrpahRuntime with the following SQL:
SELECT DayTime AS TheDate, Sum(Device1) As DeviceTotal
FROM HistoryRuntime
WHERE (DayTime >= "2017-06-01") and (DayTime <= "2017-06-26")
Group by Date(DayTime)
Using the Field Editor in the Delphi IDE, I can add two persistent fields, getting TheDate as a TDateTimeField and DeviceTotal as a TLargeIntField.
I run this query in a program to create a TeeChart, which I created at design time. As long as the query returns some records, all this works. However, if there are no records for the requested dates, I get an EDatabaseError exception with the message:
qryGrpahRuntime: Type mismatch for field 'DeviceTotal', expecting: LargeInt actual: Widestring
I have done plenty of searching for solutions on the web on how to prevent this error on an empty query, but have had not luck with anything I found. From what I can tell, SQLite defaults to the wide string field when no data is returned. I have tried using CAST in the query and it did not seem to make any difference.
If I remove the persistent fields, the query will open without problems on an empty return set. However, in order to use the TeeChart editor in the IDE, it appears I need persistent fields.
Is there a way I can make this work with persistent fields, or am I going to have to throw out the persistent fields and then add the TeeChart Series at runtime?
This behavior is described in Adjusting FireDAC Mapping chapter of the FireDAC's SQLite manual:
For an expression in a SELECT list, SQLite avoids type name
information. When the result set is not empty, FireDAC uses the value
data types from the first record. When empty, FireDAC describes those
columns as dtWideString. To explicitly specify the column data type,
append ::<type name> to the column alias:
SELECT count(*) as "cnt::INT" FROM mytab
So modify your command e.g. this way (I used BIGINT, but you can use any pseudo data type that maps to a 64-bit signed integer data type and is not auto incrementing, which corresponds to your persistent TLargeIntField field):
SELECT
DayTime AS "TheDate",
Sum(Device1) AS "DeviceTotal::BIGINT"
FROM
HistoryRuntime
WHERE
DayTime BETWEEN {d 2017-06-01} AND {d 2017-06-26}
GROUP BY
Date(DayTime)
P.S. I did a small optimization by using BETWEEN operator (which evaluates the column value only once), and used an escape sequence for date constants (which, in real you replace by parameter, I guess; so just for curiosity).
This data type hinting is parsed by the FDSQLiteTypeName2ADDataType procedure that takes and parses column name in format <column name>::<type name> in its AColName parameter.
I am using influxDB and using line protocol to insert large set of data into Data base. Data i am getting is in the form of Key value pair, where key is long string contains Hierarchical data and value is simple integer value.
Sample Key Value data :
/path/units/unit/subunits/subunit[name\='NAME1']/memory/chip/application/filter/allocations
value = 500
/path/units/unit/subunits/subunit[name\='NAME2']/memory/chip/application/filter/allocations
value = 100
(Note Name = 2)
/path/units/unit/subunits/subunit[name\='NAME1']/memory/chip/application/filter/free
value = 700
(Note Instead of allocation it is free at the leaf)
/path/units/unit/subunits/subunit[name\='NAME2']/memory/graphics/application/filter/swap
value = 600
Note Instead of chip, graphics is in path)
/path/units/unit/subunits/subunit[name\='NAME2']/harddisk/data/size
value = 400
Note Different path but till subunit it is same
/path/units/unit/subunits/subunit[name\='NAME2']/harddisk/data/free
value=100
Note Same path but last element is different
Below is the line protocol i am using to insert data.
interface, Key= /path/units/unit/subunits/subunit[name\='NAME2']/harddisk/data/free, valueData= 500
I am Using one measurement namely, Interface. And one tag and one field set. But this DB design is causing issue for querying data.
How can I design database so that i can query like, Get all record for subunit where name = Name1 or get all size data for every hard disk.
Thanks in advance.
The Schema I'd recommend would be the following:
interface,filename=/path/units/unit/subunits/subunit[name\='NAME2']/harddisk/data/free value=500
Where filename is a tag and value is the field.
Given that the cardinality of filename in the thousands this schema should work well.
I'm writing a delphi(7 ver) application and in some place I want to execute parameterized queries (for BDE and Paradox) which will be loaded at runtime into a TQuery by the user. These queries will be stored in text files (one text file for one query). The application then, will construct for any parameter of the query, one input control (Tedit) in order to be able to accept values by the user. Also there will be a button for the execution of query. My question is how can I recognize the datatype of the query's parameter? Is there a way to get this type without of cause to be included in some way in the text file containing the query?
Create a second query from the first, but modify its where clause to ensure no rows.
SELECT * FROM MYTABLE WHERE PKFIELD IS NULL
Name your parameters so that you can establish their datatypes from the fieldtypes of this second query.
I realise this only works for relatively simple cases, but it should get you some of the way.
the advantage of using a parameter is that you don't need to know its data type.
Use the string value from the tedit
"select * from mytable where myfield = :param1"
"parambyname('param1').asstring := edit1.text"
I've made this with MySQL database. you must define some parameters, Exemple:
SELECT * FROM MyTable WHERE MyField=[ANNEE];
in this case, i have an other table, called balise, that look like this
"ID" "BALISE" "CAPTION" "DEFAULT_VALUE" "CNDT" "COMPOSANT"
"1" "ANNEE" "Année" "2014" "Properties.MaxValue=2014||Properties.MinValue=2007" 1;
in runtime, this mean that:
Make in my Panel, a TLablel that have caption Année
Make in the same line an other component type 1 (That mean in my case TcxSpinEdit), this component have défault value 2014, have Two properties Max Value=2014 and Min Value=2007, (I use RTTI to modifie this value of parameters, in Delphi ver7, use TypeInfo).
An Other Button with function called Actualise, this function have Original query, must browse an array of TBalise that i have created, take the value (In my case, take TcxSpinEdit(MyObject).Value), and replace it in the copy of my query (AnsiReplaceStr(Requete, '[ANNEE]', MyValue)), so i have the final query to execute it.
I have module in complete projet, worked with this methode, and it workk fine.