lesson_4.md

Lesson 4 - Query the database and get result back as JSON

In previous lessons, we have learnt how to build a schema and import data. Now the database has all the data we need, we will learn how to query the database to get information out.

Query data with a JavaScript script

Let's have a look at the query_data.js script.

Querying is achieved with queryDocument, you need to provide a JSON template that has type and the specific requirement(s). In our case we're looking for "team": "it" or "team": "marketing".

const team_it = await client.queryDocument(
    { type: "Employee", query: { team: "IT" } },
    { as_list: true }
);

const team_marketing = await client.queryDocument(
    { type: "Employee", query: { team: "Marketing" } },
    { as_list: true }
);

This query shows how to find an employee who lives in Stockport.

const result = await client.queryDocument({ type: "Employee", query: { address: { town: "Stockport" } }});

We won't spoil the results for you, you have to find it out yourself :-)

$ node query_data.js

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Lesson 5 - Version control: time travel, branching and rebase