feat: add json_extract_key_value_pairs UDF

udfs/community/README.md

@@ -130,6 +130,7 @@ SELECT bqutil.fn.int(1.684)
 * [jaccard](#jaccard)
 * [job_url](#job_urljob_id-string)
 * [json_extract_keys](#json_extract_keys)
+* [json_extract_key_value_pairs](#json_extract_key_value_pairs)
 * [json_extract_values](#json_extract_values)
 * [json_typeof](#json_typeofjson-string)
 * [knots_to_mph](#knots_to_mphinput_knots-float64)
@@ -1389,6 +1390,25 @@ bar
 hat
 ```
 
+### [json_extract_key_value_pairs()](json_extract_key_value_pairs.sqlx)
+Returns all key/values pairs in the input JSON as an array
+of STRUCT<key STRING, value STRING>
+Returns NULL if invalid JSON string is passed,
+
+
+```sql
+SELECT * FROM UNNEST(
+  bqutil.fn.json_extract_key_value_pairs(
+    '{"foo" : "cat", "bar": [1,2,3], "hat": {"qux": true}}'
+  )
+)
+
+key,value
+foo,"cat"
+bar,[1,2,3]
+hat,{"qux":true}
+```
+
 ### [json_extract_values()](json_extract_values.sqlx)
 Returns all values in the input JSON as an array of string
 Returns NULL if invalid JSON string is passed,

udfs/community/json_extract_key_value_pairs.sqlx

@@ -0,0 +1,51 @@
+config { hasOutput: true }
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+CREATE OR REPLACE FUNCTION ${self()}(input STRING)
+RETURNS ARRAY<STRUCT<key STRING, value STRING>>
+LANGUAGE js 
+OPTIONS(
+  description = """Returns all key/values pairs in the input JSON as an array
+of STRUCT<key STRING, value STRING>
+Returns NULL if invalid JSON string is passed,
+
+
+```sql
+SELECT * FROM UNNEST(
+  bqutil.fn.json_extract_key_value_pairs(
+    '{"foo" : "cat", "bar": [1,2,3], "hat": {"qux": true}}'
+  )
+)
+
+key,value
+foo,"cat"
+bar,[1,2,3]
+hat,{"qux":true}
+```
+"""
+) 
+AS """
+  try {
+    return Object.entries(JSON.parse(json_str))
+      .map(([k, v])=> Object.fromEntries([
+        ["key", k],
+        ["value", JSON.stringify(v)]
+      ]));
+  } catch {
+    return null;
+  }
+""";

udfs/community/test_cases.js

@@ -58,6 +58,24 @@ generate_udf_test("json_extract_keys", [
         expected_output: `cast(null as array<string>)`,
     },
 ]);
+generate_udf_test("json_extract_key_value_pairs", [
+    {
+        inputs: [`'{"foo" : "cat", "bar": 42, "hat": [1,2,3], "qux": {"bat": true}}'`],
+        expected_output: `([STRUCT("foo" AS key, "cat" AS value), STRUCT("bar" AS key, "42" AS value), STRUCT("hat" AS key, "[1,2,3]" AS value), STRUCT("qux" AS key, '{"bat":true}' AS value)])`
+    },
+    {
+        inputs: [`'{}'`],
+        expected_output: `[]`
+    },
+    {
+        inputs: [`'invalid_json'`],
+        expected_output: `cast(null as array<struct<key string, value string>>)`,
+    },
+    {
+        inputs: [`string(null)`],
+        expected_output: `cast(null as array<struct<key string, value string>>)`,
+    },
+]);
 generate_udf_test("json_extract_values", [
     {
         inputs: [`'{"foo" : "cat", "bar": "dog", "hat": "rat"}'`],