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Add Query Validation

warning

This is an experimental feature. You can use the plugins for customization but they may break in future updates.

Overview​

Query validation is provided in Adhoc query and DataDoc query cells. It is done by sending the entire query every 2 seconds (debounced) after user edit.

There are 2 cases where validation will be skipped:

  1. If the query is empty.
  2. If the query contains any templating, like {{ or {%.

The query validator would return an array of errors and warnings. They are shown on the line number gutter, inside the editor, and also on the run button.

Provided Query Validators​

Currently, Querybook provides the Presto/TrinoExplainValidator.

PrestoExplainValidator​

The validator runs by transforming the query into EXPLAIN (TYPE VALIDATE) query. It then sends the query to the original engine to check if there is any semantic errors.

Plugins​

You can provide custom query validators by defining ALL_PLUGIN_QUERY_VALIDATORS_BY_NAME under query_validation_plugin. To learn how to use plugins, checkout the plugin guide. Note that the custom query validators must inherit BaseQueryValidator which lives in querybook/server/lib/query_analysis/validation/base_query_validator.py.

How to use​

First make sure the query validator you want to use is configured either thru plugins or provided by default. Note each validator only works for a single language. For example, you cannot use PrestoExplainValidator for MySQL as it would error automatically.

To configure a query validator to a query engine, go to the admin query engine page and scroll to Additional Features. Select the validator you want to use under Query Validator and hit save. Now refresh the page and the validation will be turned on.