Docs · Connecting to data

The library

Data sources, collections and variables kept outside any Check — and which of them are copied, linked or simply in scope.

Connections and queries kept outside any check. Adding one to a check copies it — what the check holds is then its own.

The library holds three things, and they relate to a Check in three different ways. Getting that straight saves a lot of confusion.

#Data sources

A full connection, query and credentials kept outside any Check.

Create one from the library's Add menu, or from a Check's source editor with Save to library — "The connection, the query and the credentials are copied as they are now." The source has to be saved first, because the library copies what is stored.

Adding one to a Check copies it. The entry's own editor says so plainly:

This is the library's own copy. Editing it changes what the next check starts from, never a check already using it.

And deleting one is safe for the same reason: "Checks that started from it keep their own copy and are not affected."

Two fields exist only on a library entry, and both are for the next person:

• What it is for — "The line the next person reads when choosing between four Oracles."
• Tags

Some entries are not written by anybody: installing a system such as Shopify puts its queries here. They carry the system's logo instead of their driver's, their tags name the system and the query and cannot be removed, and they follow the system's connection while they stay in the library. See Queries a system arrives with.

A library source also declares its parameters: what it asks a Check for. Every Check that adds it starts from those — the type, the default and the list — and is told what arrived: ""Daily sales — POS" added, with 2 parameter(s) it needs."

#Collections

A named list, held in the library so several data sources can point at the same one.

Two kinds, and the choice is locked once anything is attached:

• Machines to run against — can be attached to a data source and run across.
• Values to pick from — connects to nothing; it only supplies what a parameter sends.

A collection is attached from a data source's Connection tab, not added to a Check. Attached, it is read live:

Attached to 6 data source(s). Saving a change here changes what all of them run against.

Deleting one that is in use is refused loudly, because those sources will stop running.

A value list can also include other value lists — "Their values are read as part of this list, and follow their own edits. Duplicates collapse." — and can be loaded straight from Business Locations, one row per place at a chosen rung.

See Running across many machines for host lists in use, and how a list is imported.

#Variables

Named values every Check can read as {{name}}.

A variable saved here resolves in every check, without being added to any of them.

Any Check can override one by declaring a parameter of the same name, and both ends say so: the library entry reports "Overridden in 2 check(s)", and the overriding parameter offers Use the library value to revert.

A variable is a Check parameter minus the things that only make sense inside a Check — there is no enabled switch and no run-time override box.

#Finding things

The library has a tab each for All, Data sources, Collections and Variables, with a count on each, and a search across them.

Empty, it tells you both ways in:

Start one here with New, or configure a data source in a check and press Save to library. Either way it is then one click away in every check you write after it.