Fix SQL query to check for empty storage value.

db/migrations/00014_create_stored_functions.sql

@@ -1,18 +1,26 @@
 -- +goose Up
-
-
 -- +goose StatementBegin
--- returns if a storage node at the provided path was removed in the range >= the provided height and <= the provided block hash
-CREATE OR REPLACE FUNCTION was_state_leaf_removed(state_leaf_key BYTEA, block_num BIGINT) RETURNS BOOLEAN
+-- returns if a state leaf node was removed within the provided block number
+CREATE OR REPLACE FUNCTION was_state_leaf_removed(key character varying, hash character varying) RETURNS boolean
+    LANGUAGE plpgsql
 AS $$
-SELECT exists(SELECT 1
-              FROM eth.state_cids
-                       INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
-              WHERE state_leaf_key = state_leaf_key
-                AND block_number <= block_num
-                AND state_cids.node_type = 3
-              LIMIT 1);
-$$ LANGUAGE SQL;
+DECLARE
+    rec RECORD;
+BEGIN
+    FOR rec IN SELECT state_cids.node_type
+               FROM eth.state_cids
+                        INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
+               WHERE state_leaf_key = key
+                 AND block_number <= (SELECT block_number FROM eth.header_cids WHERE block_hash = hash)
+               ORDER BY state_cids.id DESC LIMIT 1
+        LOOP
+            IF rec.node_type = 3 THEN
+                RETURN TRUE;
+            END IF;
+        END LOOP;
+    RETURN FALSE;
+END;
+$$;
 -- +goose StatementEnd
 
 -- +goose StatementBegin