You can write regular PostgreSQL queries here, for example:

SELECT * FROM "Users" u WHERE u.name LIKE '%John%'

Passing parameters to the query

You can add params to your query by naming them $1, $2, $3, ... When you use this query in the frontend, you can dinamically fill the parameters:

SELECT * FROM "Users" u WHERE u.name = $1

Insert example:

INSERT INTO "Users"(name, email) VALUES ($1,$2)

Update example:

UPDATE "Users" SET name = $1 WHERE u.email = $2

Delete example:

DELETE FROM "Users" WHERE u.email = $1