Tutorial: Building with CleaveDB

Filtering with WHERE

You often need to compute aggregate statistics over a subset of documents rather than an entire bucket. In CleaveQL, the WHERE clause accepts comparison operators (=, !=, >, <, >=, <=) connected with AND and OR.

Flexible WHERE positioning

In DISTILL queries, the WHERE clause can be positioned immediately after the bucket or placed at the end of the query:

DISTILL FROM staff WHERE dept = "Eng" TOTAL age

Or placed after the aggregation function:

DISTILL FROM staff COUNT WHERE status = "active"

Both styles execute identically in CleaveDB's AST compiler.

Numeric comparison filters

Filter numeric ranges before tallying or computing totals:

DISTILL FROM staff WHERE age > 25 COUNT

This counts only staff members whose age strictly exceeds 25.

Compound boolean logic (AND / OR)

Combine multiple criteria using standard boolean operators:

DISTILL FROM staff WHERE dept = "Eng" AND age > 30 COUNT

You can also combine conditions using OR alongside aliases:

DISTILL FROM staff WHERE dept = "Eng" OR age < 5 TALLY AS n

This tallies all qualifying documents and assigns the output key to "n".