A boolean type with possible values of true and false.
EdgeQL has case-insensitive keywords and that includes the boolean literals:
db>
select (True, true, TRUE);{(true, true, true)}db>
select (False, false, FALSE);{(false, false, false)}A boolean value may arise as a result of a logical or comparison
operations as well as in
and not in:
db>
select true and 2 < 3;{true}db>
select '!' IN {'hello', 'world'};{false}It is also possible to cast between
bool, str, and json:
db>
select <json>true;{'true'}db>
select <bool>'True';{true}Filter clauses must always evaluate to a boolean:
select User
filter .name ilike 'alice';The and and or operators are commutative.
The truth tables are as follows:
|
a |
b |
a |
a |
|
|---|---|---|---|---|
|
true |
true |
true |
true |
false |
|
true |
false |
false |
true |
false |
|
false |
true |
false |
true |
true |
|
false |
false |
false |
false |
true |
It is important to understand the difference between using
and/or vs all()/any(). This difference is
in how they handle {}. Both and and or operators apply to
the cross-product of their operands. Thus if any of the operands are
{}, the result is also {} for and and or.
The all() and any() are generalized to apply to
sets of values, including {}. Thus they have the following truth
table:
|
a |
b |
|
|
|---|---|---|---|
|
true |
true |
true |
true |
|
true |
false |
false |
true |
|
{} |
true |
true |
true |
|
{} |
false |
false |
false |
|
false |
true |
false |
true |
|
false |
false |
false |
false |
|
true |
{} |
true |
true |
|
false |
{} |
false |
false |
|
{} |
{} |
true |
false |
Since all() and any() apply to sets as a whole,
missing values (represented by {}) are just that - missing. They
don’t affect the overall result.
To understand the last line in the above truth table it’s useful to
remember that all({a, b}) = all(a) and all(b) and any({a, b}) =
any(a) or any(b).
For more customized handling of {} the ??
should be used.
