Logical AND (∧ / AND)

Syntax

<condition1> ∧ <condition2>
<condition1> AND <condition2>

σ age > 18 ∧ active = true (Users)

Description

AND combines two conditions and keeps a row only when BOTH are true. Use it to narrow a filter — "adults who are also active", "orders that are paid and shipped". Chain as many as you like.

Technical Description

∧ forms an AndPredicate. Under three-valued logic, TRUE ∧ TRUE = TRUE; any FALSE makes it FALSE; otherwise UNKNOWN. AND binds tighter than OR and looser than NOT. The optimizer splits a conjunctive selection into separate selections so each conjunct can be pushed independently toward its source (SEL-001).

Examples

Two conditions both required:

σ age > 18 ∧ active = true (Users)

SELECT age > 18 AND active = true (Users)

Three-way conjunction:

σ region = "EMEA" ∧ amount > 1000 ∧ status = "paid" (Orders)

SELECT region = "EMEA" AND amount > 1000 AND status = "paid" (Orders)

In a join condition:

A ⟕ A.id = B.id ∧ A.active = true B

A |>< A.id = B.id AND A.active = true B

Limitations

With NULLs, a row where one side is UNKNOWN is not kept unless the other side makes the whole expression FALSE-or-TRUE per three-valued logic. Use parentheses when mixing with OR to make precedence explicit.

Alternatives

OR (∨) for "either condition". NOT (¬) to negate. IN (∈) is cleaner than a long chain of = … ∨ = … equalities.

See Also

or, not, comparison, select

Notes

Because conjuncts are split and pushed independently, writing one σ with several ANDs is as efficient as nesting separate σ operators.