With Blocks

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.

  1. const x = e.int64(3);
  2. const y = e.select(e.op(x, '^', x));
  4. y.toEdgeQL();
  5. // WITH x := 3
  6. // SELECT x ^ 3
  8. const result = await y.run(client);
  9. // => 27

This hold for expressions of arbitrary complexity.

  1. const robert = e.insert(e.Person, {
  2.   name: "Robert Pattinson"
  3. });
  4. const colin = e.insert(e.Person, {
  5.   name: "Colin Farrell"
  6. });
  7. const newMovie = e.insert(e.Movie, {
  8.   title: "The Batman",
  9.   actors: e.set(colin, robert)
  10. });
  12. /*
  13. with
  14.   robert := (insert Person {  name := "Robert Pattinson"}),
  15.   colin := (insert Person {  name := "Colin Farrell"}),
  16. insert Movie {
  17.   title := "The Batman",
  18.   actors := {robert, colin}
  19. }
  20. */

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.

  1. const robert = e.insert(e.Person, {
  2.   name: "Robert Pattinson"
  3. });
  4. const colin = e.insert(e.Person, {
  5.   name: "Colin Farrell"
  6. });
  7. const newMovie = e.insert(e.Movie, {
  8.   actors: e.with([robert, colin], // list "dependencies"
  9.     e.set(robert, colin)
  10.   )
  11. })
  13. /*
  14. insert Movie {
  15.   title := "The Batman",
  16.   actors := (
  17.     with
  18.       robert := (insert Person {  name := "Robert Pattinson"}),
  19.       colin := (insert Person {  name := "Colin Farrell"})
  20.     select {robert, colin}
  21.   )
  22. }
  23. */

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.

  1. const a = e.set(1, 2, 3);
  2. const b = e.alias(a);
  4. const query = e.select(e.op(a, '*', b))
  5. // WITH
  6. //   a := {1, 2, 3},
  7. //   b := a
  8. // SELECT a + b
  10. const result = await query.run(client);
  11. // => [1, 2, 3, 2, 4, 6, 3, 6, 9]