This is an alpha release of FnordMetric. Expect bugs and vulnerabilities.

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ChartSQL Overview

The ChartSQL query language is a superset of standard SQL. It isn't feature complete yet, but it supports all the operations you would expect in your standard SQL database like GROUP BY or HAVING statements and joins.

These are the main differences between ChartSQL and standard SQL:

The DRAW Statement

The DRAW statement allows you to specify that the query result should be returned as a chart (or other visualization) rather than a table. Here is a simple example of the DRAW statement:

DRAW LINECHART
    WITH AXIS BOTTOM

SELECT time AS x, value AS y
    FROM example_data;

Read the documentation for the DRAW statement

The IMPORT Statement

The IMPORT statement allows you to import tables from External Data Sources, like CSV files or a MySQL database. Here is a sample example of the IMPORT statement:

IMPORT TABLE example_data
    FROM 'csv:examples/data/measurement.csv?headers=true';

SELECT * FROM example_data;

Read the documentation for the IMPORT statement

The GROUP OVER TIMEWINDOW Clause

FnordMetric introduces a new GROUP OVER TIMEWINDOW clause to simplify time based rollups when working with timeseries data. Here is a simple example of the GROUP OVER TIMEWINDOW clause:

-- compute a moving average with a 60 second window
SELECT time, mean(value) FROM mymetric GROUP OVER TIMEWINDOW(60);

Read the documentation for the GROUP OVER TIMEWINDOW clause

Other Extensions to standard SQL

GROUP BY and HAVING extensions

Like MySQL, fnordmetric SQL extends the use of GROUP BY so that the select list can refer to nonaggregated columns not named in the GROUP BY clause. This assumes that the nongrouped columns will have the same group-wise values. Otherwise, the result is undefined. The same applies for the HAVING clause.

If you use a group function in a statement containing no GROUP BY clause, it will emit a single group.