kylebrandt

func TestWhereOnNullNumber(t *testing.T) {
	f := &data.Frame{
		RefID: "a",
		Name:  "a",
		Fields: []*data.Field{
			//data.NewField("d", nil, []*float64{p(2.35), p(math.NaN())}),
			data.NewField("d", nil, []float64{2.35, math.NaN()}),
		},
	}

kylebrandt

SQL Expressions -- Errors, No Data and Dynamic Schema Query Responses

There are three general situations that SQL expressions does not handle gracefully that users should be aware of that are not bugs, but rather current limitations of the feature. Those are:

1. Error Responses
2. No Data Responses
3. Dynamic Schema responses (Ones where columns are labels change between executions of the query)

Why are there these limitations?

kylebrandt

{
  "__inputs": [
    {
      "name": "DS_MOCK",
      "label": "Mock",
      "description": "",
      "type": "datasource",
      "pluginId": "grafana-mock-datasource",
      "pluginName": "Mock"
    },

kylebrandt

Dataplane FAQ

Note: much of this is moved to grafana/dataplane#56

How does dataplane relate to Dataframes?

Dataplane adds a data typing layer on top of data frames. By analogy Dataplane Types are to dataframes as typescript is to javascript.

Specifically, a property is added to the dataframe to indicate its type with is made up of a kind and a format, for example "Timeseries Wide".

kylebrandt

HTTP/1.1 200 OK
Audit-Id: 5b82aaf1-4ba7-48bc-bb7b-94a7b89c6c5e
Cache-Control: no-store
Content-Type: application/json
X-Content-Type-Options: nosniff
X-Frame-Options: deny
X-Xss-Protection: 1; mode=block
Date: Fri, 19 Sep 2025 14:51:41 GMT
Content-Length: 902
Connection: close

kylebrandt

The queries

Panel: Main Sheet

SQL:

SELECT title, author, copyright, href, image, rating, series
FROM main

kylebrandt

/* Long 
WITH movie_genre AS (
  SELECT
    A.title,
    A.year,
    B.Genre AS genre
  FROM A
  JOIN B ON A.imdb_id = B.imdb_id
),
genre_totals AS (

kylebrandt

Smooth Time Series (PromQL DS)

Trend line over Time Series (PromQL DS)

Aggregation and Math across Different Queries (Azure Metrics)

Calculate percentage of syn packages against total packets, per direction

kylebrandt

package sql

import (
	"context"
	"time"

	mysql "github.com/dolthub/go-mysql-server/sql"
	"github.com/dolthub/go-mysql-server/sql/types"
)

kylebrandt

📘 Basic Usage of SQL Expressions in Grafana

SQL expressions in Grafana let you perform lightweight SQL-like transformations on the results of other queries — directly within the panel. This is great for reshaping, renaming, filtering, and aggregating data without modifying the original datasource query.

---

🔧 How SQL Expressions Work

SQL expressions operate on the output of another query in the same panel, referenced by its query letter (e.g., A, B). These expressions are parsed and executed by Grafana — not sent to an external database.