Handle case of table with no supported columns

prestodb · Dec 13, 2023 · 333ae21 · 333ae21
1 parent 8584c85
commit 333ae21
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Showing 2 changed files with 14 additions and 9 deletions.
diff --git a/presto-base-jdbc/src/main/java/com/facebook/presto/plugin/jdbc/BaseJdbcClient.java b/presto-base-jdbc/src/main/java/com/facebook/presto/plugin/jdbc/BaseJdbcClient.java
@@ -232,8 +232,10 @@ public List<JdbcColumnHandle> getColumns(ConnectorSession session, JdbcTableHand
     {
         try (Connection connection = connectionFactory.openConnection(JdbcIdentity.from(session))) {
             try (ResultSet resultSet = getColumns(tableHandle, connection.getMetaData())) {
+                int allColumns = 0;
                 List<JdbcColumnHandle> columns = new ArrayList<>();
                 while (resultSet.next()) {
+                    allColumns++;
                     JdbcTypeHandle typeHandle = new JdbcTypeHandle(
                             resultSet.getInt("DATA_TYPE"),
                             resultSet.getString("TYPE_NAME"),
@@ -249,8 +251,12 @@ public List<JdbcColumnHandle> getColumns(ConnectorSession session, JdbcTableHand
                     }
                 }
                 if (columns.isEmpty()) {
-                    // In rare cases (e.g. PostgreSQL) a table might have no columns.
-                    throw new TableNotFoundException(tableHandle.getSchemaTableName());
+                    // A table may have no supported columns. In rare cases (e.g. PostgreSQL) a table might have no columns at all.
+                    // Throw an exception if the table has no supported columns.
+                    // This can occur if all columns in the table are of unsupported types, or in rare cases, if the table has no columns at all.
+                    throw new TableNotFoundException(
+                            tableHandle.getSchemaTableName(),
+                            format("Table '%s' has no supported columns (all %s columns are not supported)", tableHandle.getSchemaTableName(), allColumns));
                 }
                 return ImmutableList.copyOf(columns);
             }

diff --git a/...c/test/java/com/facebook/presto/plugin/postgresql/TestPostgreSqlIntegrationSmokeTest.java b/...c/test/java/com/facebook/presto/plugin/postgresql/TestPostgreSqlIntegrationSmokeTest.java
@@ -128,14 +128,13 @@ public void testTableWithNoSupportedColumns()
                 AutoCloseable ignore2 = withTable("tpch.supported_columns", format("(good %s)", supportedDataType));
                 AutoCloseable ignore3 = withTable("tpch.no_columns", "()")) {
             assertThat(computeActual("SHOW TABLES").getOnlyColumnAsSet()).contains("orders", "no_supported_columns", "supported_columns", "no_columns");
+            assertQueryFails("SELECT c FROM tpch.no_supported_columns", "\\QTable 'tpch.no_supported_columns" + "' has no supported columns (all 1 columns are not supported)");
+            assertQueryFails("SELECT * FROM tpch.no_supported_columns", "\\QTable 'tpch.no_supported_columns" + "' has no supported columns (all 1 columns are not supported)");
+            assertQueryFails("SELECT 'a' FROM tpch.no_supported_columns", "\\QTable 'tpch.no_supported_columns" + "' has no supported columns (all 1 columns are not supported)");
 
-            assertQueryFails("SELECT c FROM no_supported_columns", "Table 'tpch.no_supported_columns' not found");
-            assertQueryFails("SELECT * FROM no_supported_columns", "Table 'tpch.no_supported_columns' not found");
-            assertQueryFails("SELECT 'a' FROM no_supported_columns", "Table 'tpch.no_supported_columns' not found");
-
-            assertQueryFails("SELECT c FROM no_columns", "Table 'tpch.no_columns' not found");
-            assertQueryFails("SELECT * FROM no_columns", "Table 'tpch.no_columns' not found");
-            assertQueryFails("SELECT 'a' FROM no_columns", "Table 'tpch.no_columns' not found");
+            assertQueryFails("SELECT c FROM tpch.no_columns", "\\QTable 'tpch.no_columns" + "' has no supported columns (all 0 columns are not supported)");
+            assertQueryFails("SELECT * FROM tpch.no_columns", "\\QTable 'tpch.no_columns" + "' has no supported columns (all 0 columns are not supported)");
+            assertQueryFails("SELECT 'a' FROM tpch.no_columns", "\\QTable 'tpch.no_columns" + "' has no supported columns (all 0 columns are not supported)");
 
             assertQueryFails("SELECT c FROM non_existent", ".*Table .*tpch.non_existent.* does not exist");
             assertQueryFails("SELECT * FROM non_existent", ".*Table .*tpch.non_existent.* does not exist");