Feature: Add support for application/x-www-form-urlencoded encoding

docs/README.md

@@ -14,6 +14,9 @@ LOAD http_client;
 ### Functions
 - `http_get(url)`
 - `http_post(url, headers, params)`
+  - Sends POST request with params encoded as a JSON object
+- `http_post_form(url, headers, params)`
+  - Sends POST request with params being `application/x-www-form-urlencoded` encoded (used by many forms and some APIs)
 
 ### Examples
 #### GET
@@ -83,6 +86,44 @@ D WITH __input AS (
 └────────┴─────────┴─────────────┘
 ```
 
+#### POST using form encoding(application/x-www-form-urlencoded, not multipart/form-data)
+```sql
+D WITH __input AS (
+  SELECT
+    http_post_form(
+        'https://httpbin.org/delay/0',
+        headers => MAP {
+          'accept': 'application/json',
+        },
+        params => MAP {
+          'limit': 10
+        }
+    ) AS res
+),
+__response AS (
+  SELECT
+    (res->>'status')::INT AS status,
+    (res->>'reason') AS reason,
+    unnest( from_json(((res->>'body')::JSON)->'form', '{"limit": "VARCHAR"}') ) AS features
+  FROM
+    __input
+)
+SELECT
+  __response.status,
+  __response.reason,
+  __response.limit AS limit
+FROM
+  __response
+;
+┌────────┬─────────┬─────────┐
+│ status │ reason  │  limit  │
+│ int32  │ varchar │ varchar │
+├────────┼─────────┼─────────┤
+│    200 │ OK      │ 10      │
+└────────┴─────────┴─────────┘
+```
+
+
 #### Full Example w/ spatial data
 This is the original example by @ahuarte47 inspiring this community extension.
 

src/http_client_extension.cpp

@@ -261,6 +261,46 @@ static void HTTPPostRequestFunction(DataChunk &args, ExpressionState &state, Vec
         });
 }
 
+static void HTTPPostFormRequestFunction(DataChunk &args, ExpressionState &state, Vector &result) {
+    D_ASSERT(args.data.size() == 3);
+
+    using STRING_TYPE = PrimitiveType<string_t>;
+    using LENTRY_TYPE = PrimitiveType<list_entry_t>;
+
+    auto &url_vector = args.data[0];
+    auto &headers_vector = args.data[1];
+    auto &headers_entry = ListVector::GetEntry(headers_vector);
+    auto &body_vector = args.data[2];
+    auto &body_entry = ListVector::GetEntry(body_vector);
+
+    GenericExecutor::ExecuteTernary<STRING_TYPE, LENTRY_TYPE, LENTRY_TYPE, STRING_TYPE>(
+        url_vector, headers_vector, body_vector, result, args.size(),
+        [&](STRING_TYPE url, LENTRY_TYPE headers, LENTRY_TYPE params) {
+            std::string url_str = url.val.GetString();
+
+            // Use helper to setup client and parse URL
+            auto client_and_path = SetupHttpClient(url_str);
+            auto &client = client_and_path.first;
+            auto &path = client_and_path.second;
+
+            // Prepare headers and parameters
+            duckdb_httplib_openssl::Headers header_map;
+            duckdb_httplib_openssl::Params params_map;
+            ConvertListEntryToMap<duckdb_httplib_openssl::Headers>(headers.val, headers_entry, header_map);
+            ConvertListEntryToMap<duckdb_httplib_openssl::Params>(params.val, body_entry, params_map);
+
+            // Make the POST request with headers and params
+            auto res = client.Post(path.c_str(), header_map, params_map);
+            if (res) {
+                std::string response = GetJsonResponse(res->status, res->reason, res->body);
+                return StringVector::AddString(result, response);
+            } else {
+                std::string response = GetJsonResponse(-1, GetHttpErrorMessage(res, "POST"), "");
+                return StringVector::AddString(result, response);
+            }
+        });
+}
+
 
 static void LoadInternal(DatabaseInstance &instance) {
     ScalarFunctionSet http_get("http_get");
@@ -276,6 +316,13 @@ static void LoadInternal(DatabaseInstance &instance) {
         {LogicalType::VARCHAR, LogicalType::MAP(LogicalType::VARCHAR, LogicalType::VARCHAR), LogicalType::JSON()},
         LogicalType::JSON(), HTTPPostRequestFunction));
     ExtensionUtil::RegisterFunction(instance, http_post);
+
+    ScalarFunctionSet http_post_form("http_post_form");
+    http_post_form.AddFunction(ScalarFunction(
+        {LogicalType::VARCHAR, LogicalType::MAP(LogicalType::VARCHAR, LogicalType::VARCHAR),
+            LogicalType::MAP(LogicalType::VARCHAR, LogicalType::VARCHAR)},
+        LogicalType::JSON(), HTTPPostFormRequestFunction));
+    ExtensionUtil::RegisterFunction(instance, http_post_form);
 }
 
 void HttpClientExtension::Load(DuckDB &db) {

test/sql/httpclient.test

@@ -134,3 +134,68 @@ FROM
 ;
 ----
 S2A_56LPN_20210930_0_L2A
+
+# Confirm the POST function with form request works
+query III
+WITH __input AS (
+  SELECT
+    http_post_form(
+        'https://httpbin.org/delay/0',
+        headers => MAP {
+          'accept': 'application/json',
+        },
+        params => MAP {
+          'limit': 10
+        }
+    ) AS res
+),
+__response AS (
+  SELECT
+    (res->>'status')::INT AS status,
+    (res->>'reason') AS reason,
+    unnest( from_json(((res->>'body')::JSON)->'headers', '{"Host": "VARCHAR"}') ) AS features
+  FROM
+    __input
+)
+SELECT
+  __response.status,
+  __response.reason,
+  __response.Host AS host
+FROM
+  __response
+;
+----
+200	OK	httpbin.org
+
+# Confirm the POST function with form encoding transmits a single value
+query III
+WITH __input AS (
+  SELECT
+    http_post_form(
+        'https://httpbin.org/delay/0',
+        headers => MAP {
+          'accept': 'application/json',
+        },
+        params => MAP {
+          'limit': 10
+        }
+    ) AS res
+),
+__response AS (
+  SELECT
+    (res->>'status')::INT AS status,
+    (res->>'reason') AS reason,
+    unnest( from_json(((res->>'body')::JSON)->'form', '{"limit": "VARCHAR"}') ) AS features
+  FROM
+    __input
+)
+SELECT
+  __response.status,
+  __response.reason,
+  __response.limit AS limit
+FROM
+  __response
+;
+----
+200	OK	10
+