add logic for delete operation to fix queries grouping by columns from a recursive query

Author: tyrelr

sqlx-core/src/sqlite/connection/explain.rs

@@ -19,6 +19,7 @@ const SQLITE_AFF_REAL: u8 = 0x45; /* 'E' */
 const OP_INIT: &str = "Init";
 const OP_GOTO: &str = "Goto";
 const OP_DECR_JUMP_ZERO: &str = "DecrJumpZero";
+const OP_DELETE: &str = "Delete";
 const OP_ELSE_EQ: &str = "ElseEq";
 const OP_EQ: &str = "Eq";
 const OP_END_COROUTINE: &str = "EndCoroutine";
@@ -875,6 +876,15 @@ pub(super) fn explain(
                     //Noop if the register p2 isn't a record, or if pointer p1 does not exist
                 }
 
+                OP_DELETE => {
+                    // delete a record from cursor p1
+                    if let Some(CursorDataType::Normal { is_empty, .. }) = state.p.get_mut(&p1) {
+                        if *is_empty == Some(false) {
+                            *is_empty = None; //the cursor might be empty now
+                        }
+                    }
+                }
+
                 OP_OPEN_PSEUDO => {
                     // Create a cursor p1 aliasing the record from register p2
                     state.p.insert(p1, CursorDataType::Pseudo(p2));