From 5ddca55405bfbeb6715ed7d9ec418076740fffa6 Mon Sep 17 00:00:00 2001
From: Keshav Dandeva <keshavdandeva@google.com>
Date: Fri, 4 Sep 2026 14:05:58 +0000
Subject: [PATCH] fix(bigquery-jdbc): resolve `statementType` via `getJob`
 fallback to avoid post-execution dry run for DDL

---
 .../bigquery/jdbc/BigQueryStatement.java      | 11 +++++++
 .../bigquery/jdbc/BigQueryStatementTest.java  | 23 ++++++++++++++
 .../bigquery/jdbc/it/ITStatementTest.java     | 30 +++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/java-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryStatement.java b/java-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryStatement.java
index 84ac6854b6b8..3fd724c820d9 100644
--- a/java-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryStatement.java
+++ b/java-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryStatement.java
@@ -617,12 +617,23 @@ private void saveSessionIdIfPresent(TableResult tableResult) {
   }
 
   private StatementType getStatementType(ExecuteResult executeResult) {
+    // Fast path: Read statementType directly from TableResult
     if (executeResult.tableResult.getStatementType() != null) {
       return executeResult.tableResult.getStatementType();
     }
+    // Jobful path: Read statementType from Job statistics when executed via JobCreationMode=1 or
+    // jobs.insert
     if (executeResult.job != null && executeResult.job.getStatistics() instanceof QueryStatistics) {
       return ((QueryStatistics) executeResult.job.getStatistics()).getStatementType();
     }
+    // Fallback path: Lazily fetch completed Job metadata to resolve statementType without dry
+    // runs if omitted in TableResult
+    if (executeResult.tableResult.getJobId() != null && this.bigQuery != null) {
+      Job job = this.bigQuery.getJob(executeResult.tableResult.getJobId());
+      if (job != null && job.getStatistics() instanceof QueryStatistics) {
+        return ((QueryStatistics) job.getStatistics()).getStatementType();
+      }
+    }
     return null;
   }
 
diff --git a/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/BigQueryStatementTest.java b/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/BigQueryStatementTest.java
index 15e99f6699a2..00b401440a2a 100644
--- a/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/BigQueryStatementTest.java
+++ b/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/BigQueryStatementTest.java
@@ -1136,4 +1136,27 @@ public void testStatelessDmlExecutionUsesTableResultWithoutDryRunOrGetJob() thro
     verify(bigquery, Mockito.never()).create(any(JobInfo.class));
     verify(bigquery, Mockito.never()).getJob(any(JobId.class));
   }
+
+  @Test
+  public void testNullStatementTypeInTableResultFallsBackToGetJobWithoutDryRun() throws Exception {
+    TableResult tableResultMock = mock(TableResult.class);
+    doReturn(this.jobId).when(tableResultMock).getJobId();
+    doReturn(null).when(tableResultMock).getStatementType();
+    doReturn(0L).when(tableResultMock).getTotalRows();
+    doReturn(Schema.of()).when(tableResultMock).getSchema();
+
+    doReturn(tableResultMock)
+        .when(bigquery)
+        .queryWithTimeout(any(QueryJobConfiguration.class), any(), any());
+
+    Job jobMock = getJobMock(null, null, StatementType.CREATE_TABLE);
+    doReturn(jobMock).when(bigquery).getJob(eq(this.jobId));
+
+    boolean result = bigQueryStatement.execute("CREATE TABLE dataset.my_table (x INT64)");
+
+    assertFalse(result);
+    assertNull(bigQueryStatement.getResultSet());
+    verify(bigquery, Mockito.times(1)).getJob(eq(this.jobId));
+    verify(bigquery, Mockito.never()).create(any(JobInfo.class));
+  }
 }
diff --git a/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/it/ITStatementTest.java b/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/it/ITStatementTest.java
index 9790284b664e..e73f2395b493 100644
--- a/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/it/ITStatementTest.java
+++ b/java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/it/ITStatementTest.java
@@ -460,4 +460,34 @@ public void testSessionPersistenceAcrossQueries() throws SQLException {
       }
     }
   }
+
+  @Test
+  public void testNonIdempotentCreateTableAndDrop() throws SQLException {
+    String tempTableName = "NON_IDEMPOTENT_TABLE_" + Math.abs(random.nextInt(100000));
+    String createTableQuery =
+        String.format("CREATE TABLE %s.%s (`id` INT64, `name` STRING);", DATASET, tempTableName);
+    String dropTableQuery = String.format("DROP TABLE %s.%s;", DATASET, tempTableName);
+
+    try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+        Statement statement = connection.createStatement()) {
+      boolean hasResultSet = statement.execute(createTableQuery);
+      assertFalse(hasResultSet);
+      assertEquals(0, statement.getUpdateCount());
+
+      try (ResultSet rs =
+          statement.executeQuery(
+              String.format("SELECT count(*) FROM %s.%s;", DATASET, tempTableName))) {
+        assertTrue(rs.next());
+        assertEquals(0L, rs.getLong(1));
+        assertFalse(rs.next());
+      }
+    } finally {
+      try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+          Statement statement = connection.createStatement()) {
+        statement.execute(dropTableQuery);
+      } catch (SQLException ignored) {
+        // Ignore cleanup exception if table was not created
+      }
+    }
+  }
 }