SQL: improve ResultSet behavior when no rows are available (#46753)

Improve the defensive behavior of ResultSet when dealing with incorrect
API usage. In particular handle the case of dealing with no row
available (either because the cursor is before the first entry or after
the last).

Fix #46750

(cherry picked from commit 58fa38e)

x-pack/plugin/sql/jdbc/src/main/java/org/elasticsearch/xpack/sql/jdbc/JdbcResultSet.java

@@ -37,8 +37,8 @@
 import static org.elasticsearch.xpack.sql.jdbc.EsType.DATETIME;
 import static org.elasticsearch.xpack.sql.jdbc.EsType.TIME;
 import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.asDateTimeField;
-import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.dateTimeAsMillisSinceEpoch;
 import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.asTimestamp;
+import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.dateTimeAsMillisSinceEpoch;
 import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.timeAsMillisSinceEpoch;
 import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.timeAsTime;
 import static org.elasticsearch.xpack.sql.jdbc.JdbcDateUtils.timeAsTimestamp;
@@ -57,6 +57,7 @@ class JdbcResultSet implements ResultSet, JdbcWrapper {
 
     private boolean closed = false;
     private boolean wasNull = false;
+    private boolean wasLast = false;
 
     private int rowNumber;
 
@@ -78,10 +79,13 @@ private Object column(int columnIndex) throws SQLException {
         if (columnIndex < 1 || columnIndex > cursor.columnSize()) {
             throw new SQLException("Invalid column index [" + columnIndex + "]");
         }
+        if (wasLast == true || rowNumber < 1) {
+            throw new SQLException("No row available");
+        }
         Object object = null;
         try {
             object = cursor.column(columnIndex - 1);
-        } catch (IllegalArgumentException iae) {
+        } catch (Exception iae) {
             throw new SQLException(iae.getMessage());
         }
         wasNull = (object == null);
@@ -114,6 +118,7 @@ public boolean next() throws SQLException {
             rowNumber++;
             return true;
         }
+        wasLast = true;
         return false;
     }
 
@@ -461,7 +466,7 @@ public boolean isBeforeFirst() throws SQLException {
 
     @Override
     public boolean isAfterLast() throws SQLException {
-        throw new SQLFeatureNotSupportedException("isAfterLast not supported");
+        return rowNumber > 0 && wasLast;
     }
 
     @Override

x-pack/plugin/sql/qa/src/main/java/org/elasticsearch/xpack/sql/qa/jdbc/ResultSetTestCase.java

@@ -1449,6 +1449,34 @@ public void testUnsupportedUpdateMethods() throws IOException, SQLException {
         assertThrowsWritesUnsupportedForUpdate(() -> r.rowDeleted());
     }
 
+    public void testResultSetNotInitialized() throws Exception {
+        createTestDataForNumericValueTypes(() -> randomInt());
+
+        SQLException sqle = expectThrows(SQLException.class, () -> {
+            doWithQuery(SELECT_WILDCARD, rs -> {
+                assertFalse(rs.isAfterLast());
+                rs.getObject(1);
+            });
+        });
+        assertEquals("No row available", sqle.getMessage());
+    }
+
+    public void testResultSetConsumed() throws Exception {
+        createTestDataForNumericValueTypes(() -> randomInt());
+
+        SQLException sqle = expectThrows(SQLException.class, () -> {
+            doWithQuery("SELECT * FROM test LIMIT 1", rs -> {
+                assertFalse(rs.isAfterLast());
+                assertTrue(rs.next());
+                assertFalse(rs.isAfterLast());
+                assertFalse(rs.next());
+                assertTrue(rs.isAfterLast());
+                rs.getObject(1);
+            });
+        });
+        assertEquals("No row available", sqle.getMessage());
+    }
+
     private void doWithQuery(String query, CheckedConsumer<ResultSet, SQLException> consumer) throws SQLException {
         doWithQuery(() -> esJdbc(timeZoneId), query, consumer);
     }