Use the data stream entity name in name/value pairs.

modules/core/data_stream/src/Traits/DataStreamSqlStorage.php

@@ -48,6 +48,7 @@ trait DataStreamSqlStorage {
     $result = $query->execute();
 
     // Build an array of data.
+    $name = $stream->label();
     $data = [];
     foreach ($result as $row) {
 
@@ -63,7 +64,7 @@ trait DataStreamSqlStorage {
       // Create a data object for the sensor value.
       $point = new \stdClass();
       $point->timestamp = $row->timestamp;
-      $point->value = $value;
+      $point->{$name} = $value;
       $data[] = $point;
     }
 
@@ -115,8 +116,8 @@ trait DataStreamSqlStorage {
     // Iterate over the JSON properties.
     foreach ($data as $key => $value) {
 
-      // If the key is "timestamp", skip to the next property in the JSON.
-      if ($key == 'timestamp') {
+      // If the key does not match the data stream name, skip it.
+      if ($key !== $stream->label()) {
         continue;
       }
 

modules/core/data_stream/tests/src/Kernel/DataStreamApiTest.php

@@ -145,10 +145,11 @@ class DataStreamApiTest extends DataStreamTestBase {
 
     // Test data.
     $timestamp = $this->startTime - 86400;
-    $test_data = ['timestamp' => $timestamp, 'value' => 200];
+    $name = $this->dataStream->label();
+    $test_data = ['timestamp' => $timestamp, $name => 200];
     $test_point = new \stdClass();
     $test_point->timestamp = $test_data['timestamp'];
-    $test_point->value = $test_data['value'];
+    $test_point->{$name} = 200;
 
     // Make a request.
     $request = Request::create($uri, 'POST', [], [], [], [], Json::encode($test_data));

modules/core/data_stream/tests/src/Traits/DataStreamCreationTrait.php

@@ -58,11 +58,12 @@ trait DataStreamCreationTrait {
 
     $data = [];
 
+    $name = $stream->label();
     $value = 0;
     for ($x = 0; $x < $count; $x++) {
       $data[] = [
         'timestamp' => $start_time,
-        'value' => $value,
+        $name => $value,
       ];
       $start_time += 86400;
       $value += 1;