Using the SQL CLI

Use the SQL CLI to validate your analytics configuration before moving on to other analytics tools. The CLI is a fully-featured interactive SQL environment in its own right.

Installing the CLI

Download the Presto CLI and follow the instructions to make the jar executable.

Using the CLI

You will typically launch the SQL CLI with three arguments:

  • The required --server argument specifies the analytics server address. Because you are connecting through the local datomic-access proxyl this will be localhost:8989.
  • The optional --catalog argument must match a catalog configured for your system.
  • The optional --schema argument must be the name of a Datomic database.

The catalog and schema arguments are defaults for queries that do not explicitly name a catalog and schema, so that in your queries you can use table names directly, e.g. country instead of tomhanks.mbrainz.country.

./presto --server localhost:8989 --catalog <my-catalog> --schema <db-name>

You should be presented with a SQL prompt:

presto>

Validating Configuration

The examples below presume a Datomic system named tomhanks with a database named mbrainz, and a SQL CLI launched with:

./presto --server localhost:8989 --catalog tomhanks --schema mbrainz

Catalogs

The following query shows all catalogs.

select * from system.metadata.catalogs;
 catalog_name | connector_id 
--------------+--------------
 system       | system       
 tomhanks     | tomhanks  

You should see a system catalog, plus one entry per catalog properties file. In this example above, the Datomic catalog name is tomhanks.

Show Schemas

The following query shows all the schemas in the default catalog:

show schemas;
       Schema       
--------------------
 information_schema 
 mbrainz   

You should see an information_schema catalog, plus one schema per exposed Datomic database. In the example above, the tomhanks system has a single database named mbrainz.

Show Tables

The following query shows all the tables in the default schema.

presto> show tables;
	   Table           
---------------------------
 abstractrelease           
 abstractrelease_x_artists 
 artist                    
 artist_gender             
 artist_type               
 country                   
 db__attrs                 
 db__idents               
 (continues...)

You should see db__attrs and db__idents, plus any tables you have configured via a metaschema.

Describe a Table

The following query describes a table named country in the default schema:

describe country;
 Column |  Type   | Extra | Comment 
--------+---------+-------+---------
 code   | varchar |       |         
 name   | varchar |       |         
 db__id | bigint  |       |         

More Things To Try

Try some of the system commands to see what is present in the system.

You can access more than one database (or even more than one catalog) by using fully qualified table names in you SQL, e.g. [catalog].[database].[table]. You can also write queries that join across different databases or catalogs.