More changes to Cloud Spanner budget-transfer samples (GoogleCloudPlatform#902)

Author: hegemonic

spanner/src/read_write_transaction.php

@@ -32,9 +32,9 @@
  * Performs a read-write transaction to update two sample records in the
  * database.
  *
- * This will transfer 100,000 from the `MarketingBudget` field for the second
- * Album to the first Album. If the `MarketingBudget` is too low, it will
- * raise an exception.
+ * This will transfer 200,000 from the `MarketingBudget` field for the second
+ * Album to the first Album. If the `MarketingBudget` for the second Album is
+ * too low, it will raise an exception.
  *
  * Before running this sample, you will need to run the `update_data` sample
  * to populate the fields.
@@ -53,6 +53,8 @@ function read_write_transaction($instanceId, $databaseId)
     $database = $instance->database($databaseId);
 
     $database->runTransaction(function (Transaction $t) use ($spanner) {
+        $transferAmount = 200000;
+
         // Read the second album's budget.
         $secondAlbumKey = [2,2];
         $secondAlbumKeySet = $spanner->keySet(['keys' => [$secondAlbumKey]]);
@@ -65,10 +67,10 @@ function read_write_transaction($instanceId, $databaseId)
 
         $firstRow = $secondAlbumResult->rows()->current();
         $secondAlbumBudget = $firstRow['MarketingBudget'];
-        if ($secondAlbumBudget < 300000) {
+        if ($secondAlbumBudget < $transferAmount) {
             // Throwing an exception will automatically roll back the transaction.
             throw new UnexpectedValueException(
-                'The second album\'s budget doesn\'t meet the required minimum'
+                'The second album\'s budget is lower than the transfer amount: ' . $transferAmount
             );
         }
 
@@ -86,24 +88,21 @@ function read_write_transaction($instanceId, $databaseId)
         $firstAlbumBudget = $firstRow['MarketingBudget'];
 
         // Update the budgets.
-        $transferAmount = 100000;
-        if ($firstAlbumBudget >= $transferAmount) {
-            $secondAlbumBudget += $transferAmount;
-            $firstAlbumBudget -= $transferAmount;
-            printf('Setting first album\'s budget to %s and the second album\'s ' .
-                'budget to %s.' . PHP_EOL, $firstAlbumBudget, $secondAlbumBudget);
+        $secondAlbumBudget -= $transferAmount;
+        $firstAlbumBudget += $transferAmount;
+        printf('Setting first album\'s budget to %s and the second album\'s ' .
+            'budget to %s.' . PHP_EOL, $firstAlbumBudget, $secondAlbumBudget);
 
-            // Update the rows.
-            $t->updateBatch('Albums', [
-                ['SingerId' => 1, 'AlbumId' => 1, 'MarketingBudget' => $firstAlbumBudget],
-                ['SingerId' => 2, 'AlbumId' => 2, 'MarketingBudget' => $secondAlbumBudget],
-            ]);
+        // Update the rows.
+        $t->updateBatch('Albums', [
+            ['SingerId' => 1, 'AlbumId' => 1, 'MarketingBudget' => $firstAlbumBudget],
+            ['SingerId' => 2, 'AlbumId' => 2, 'MarketingBudget' => $secondAlbumBudget],
+        ]);
 
-            // Commit the transaction!
-            $t->commit();
+        // Commit the transaction!
+        $t->commit();
 
-            print('Transaction complete.' . PHP_EOL);
-        }
+        print('Transaction complete.' . PHP_EOL);
     });
 }
 // [END spanner_read_write_transaction]

spanner/src/write_data_with_dml_transaction.php

@@ -31,9 +31,9 @@
  * Performs a read-write transaction to update two sample records in the
  * database.
  *
- * This will transfer 100,000 from the `MarketingBudget` field for the first
- * Album to the second Album. If the `MarketingBudget` is too low, it will
- * raise an exception.
+ * This will transfer 200,000 from the `MarketingBudget` field for the second
+ * Album to the first Album. If the `MarketingBudget` for the second Album is
+ * too low, it will raise an exception.
  *
  * Before running this sample, you will need to run the `update_data` sample
  * to populate the fields.
@@ -54,25 +54,26 @@ function write_data_with_dml_transaction($instanceId, $databaseId)
     $database->runTransaction(function (Transaction $t) use ($spanner) {
         // Transfer marketing budget from one album to another. We do it in a transaction to
         // ensure that the transfer is atomic.
+        $transferAmount = 200000;
+
         $results = $t->execute(
-            "SELECT MarketingBudget from Albums WHERE SingerId = 1 and AlbumId = 1"
+            "SELECT MarketingBudget from Albums WHERE SingerId = 2 and AlbumId = 2"
         );
         $resultsRow = $results->rows()->current();
-        $album1budget = $resultsRow['MarketingBudget'];
-        $transferAmount = 100000;
+        $album2budget = $resultsRow['MarketingBudget'];
 
         // Transaction will only be committed if this condition still holds at the time of
         // commit. Otherwise it will be aborted and the callable will be rerun by the
         // client library.
-        if ($album1budget >= $transferAmount) {
+        if ($album2budget >= $transferAmount) {
             $results = $t->execute(
-                "SELECT MarketingBudget from Albums WHERE SingerId = 2 and AlbumId = 2"
+                "SELECT MarketingBudget from Albums WHERE SingerId = 1 and AlbumId = 1"
             );
             $resultsRow = $results->rows()->current();
-            $album2budget = $resultsRow['MarketingBudget'];
+            $album1budget = $resultsRow['MarketingBudget'];
 
-            $album2budget += $transferAmount;
-            $album1budget -= $transferAmount;
+            $album2budget -= $transferAmount;
+            $album1budget += $transferAmount;
 
             // Update the albums
             $t->executeUpdate(

spanner/test/spannerTest.php

@@ -158,7 +158,7 @@ public function testReadWriteTransaction()
     {
         $this->runCommand('update-data');
         $output = $this->runCommand('read-write-transaction');
-        $this->assertContains('Setting first album\'s budget to 0 and the second album\'s budget to 600000', $output);
+        $this->assertContains('Setting first album\'s budget to 300000 and the second album\'s budget to 300000', $output);
         $this->assertContains('Transaction complete.', $output);
     }