# print method doesn't change unexpectedly

    Code
      sql_build(semi_join(lf1, lf2 %>% filter(z == 2)))
    Message
      Joining with `by = join_by(x)`
    Output
      <SQL SEMI JOIN>
      By:
        x-x
      Where:
        "`df_RHS`.`z` = 2.0"
      X:
        <dbplyr_table_ident[1]>
        [1] `df`
      Y:
        <dbplyr_table_ident[1]>
        [1] `df`

# generated sql doesn't change unexpectedly

    Code
      semi_join(lf, lf)
    Message
      Joining with `by = join_by(x, y)`
    Output
      <SQL>
      SELECT `df_LHS`.*
      FROM `df` AS `df_LHS`
      WHERE EXISTS (
        SELECT 1 FROM `df` AS `df_RHS`
        WHERE (`df_LHS`.`x` = `df_RHS`.`x`) AND (`df_LHS`.`y` = `df_RHS`.`y`)
      )

---

    Code
      anti_join(lf, lf)
    Message
      Joining with `by = join_by(x, y)`
    Output
      <SQL>
      SELECT `df_LHS`.*
      FROM `df` AS `df_LHS`
      WHERE NOT EXISTS (
        SELECT 1 FROM `df` AS `df_RHS`
        WHERE (`df_LHS`.`x` = `df_RHS`.`x`) AND (`df_LHS`.`y` = `df_RHS`.`y`)
      )