During the query rendering step, the number of occurrences of each expression
are tracked. If an expression occurs more than once it is automatically
extracted into a with block.
const x = e.int64(3);
const y = e.select(e.op(x, '^', x));
y.toEdgeQL();
// with x := 3
// select x ^ x
const result = await y.run(client);
// => 27This hold for expressions of arbitrary complexity.
const robert = e.insert(e.Person, {
name: "Robert Pattinson"
});
const colin = e.insert(e.Person, {
name: "Colin Farrell"
});
const newMovie = e.insert(e.Movie, {
title: "The Batman",
actors: e.set(colin, robert)
});
/*
with
robert := (insert Person { name := "Robert Pattinson"}),
colin := (insert Person { name := "Colin Farrell"}),
insert Movie {
title := "The Batman",
actors := {robert, colin}
}
*/Note that robert and colin were pulled out into a top-level with
block. To force these variables to occur in an internal with block, you
can short-circuit this logic with e.with.
const robert = e.insert(e.Person, {
name: "Robert Pattinson"
});
const colin = e.insert(e.Person, {
name: "Colin Farrell"
});
const newMovie = e.insert(e.Movie, {
actors: e.with([robert, colin], // list "dependencies"
e.select(e.set(robert, colin))
)
})
/*
insert Movie {
title := "The Batman",
actors := (
with
robert := (insert Person { name := "Robert Pattinson"}),
colin := (insert Person { name := "Colin Farrell"})
select {robert, colin}
)
}
*/It’s an error to pass an expression into multiple
e.withs, or use an expression passed to e.with outside of that
block.
To explicitly create a detached “alias” of another expression, use e.alias.
const a = e.set(1, 2, 3);
const b = e.alias(a);
const query = e.select(e.op(a, '*', b))
// WITH
// a := {1, 2, 3},
// b := a
// SELECT a + b
const result = await query.run(client);
// => [1, 2, 3, 2, 4, 6, 3, 6, 9]