Fixed argument count in the statement's metadata

Author: chernser

jdbc-v2/src/main/java/com/clickhouse/jdbc/PreparedStatementImpl.java

@@ -3,6 +3,7 @@
 import com.clickhouse.client.api.DataTypeUtils;
 import com.clickhouse.client.api.metadata.TableSchema;
 import com.clickhouse.client.api.sql.SQLUtils;
+import com.clickhouse.data.ClickHouseColumn;
 import com.clickhouse.data.ClickHouseDataType;
 import com.clickhouse.data.Tuple;
 import com.clickhouse.jdbc.internal.ExceptionUtils;
@@ -60,6 +61,8 @@
 import java.util.UUID;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 
 public class PreparedStatementImpl extends StatementImpl implements PreparedStatement, JdbcV2Wrapper {
     private static final Logger LOG = LoggerFactory.getLogger(PreparedStatementImpl.class);
@@ -251,7 +254,7 @@ public void clearParameters() throws SQLException {
     }
 
     int getParametersCount() {
-        return values.length;
+        return argCount;
     }
 
     @Override
@@ -409,7 +412,10 @@ public ResultSetMetaData getMetaData() throws SQLException {
             }
 
             if (resultSetMetaData == null) {
-                resultSetMetaData = new ResultSetMetaDataImpl(Collections.emptyList(),
+                List<ClickHouseColumn> columns = IntStream.range(0, argCount)
+                        .mapToObj(value -> ClickHouseColumn.of("v_" + value, "Nothing"))
+                        .collect(Collectors.toList());
+                resultSetMetaData = new ResultSetMetaDataImpl(columns,
                         connection.getSchema(), connection.getCatalog(),
                         "", JdbcUtils.DATA_TYPE_CLASS_MAP);
             }

jdbc-v2/src/test/java/com/clickhouse/jdbc/PreparedStatementTest.java

@@ -1404,4 +1404,16 @@ public void testCheckOfParametersAreSet() throws Exception {
             }
         }
     }
+
+    @Test
+    public void testParameterCount() throws Exception {
+        try (Connection conn = getJdbcConnection();) {
+            try (PreparedStatement stmt = conn.prepareStatement("select ?, ? as v1, ? as v2")) {
+                Assert.assertEquals(stmt.getMetaData().getColumnCount(), 3);
+            }
+            try (PreparedStatement stmt = conn.prepareStatement("WITH toDateTime(?) AS target_time SELECT * FROM table")) {
+                Assert.assertEquals(stmt.getMetaData().getColumnCount(), 1);
+            }
+        }
+    }
 }

jdbc-v2/src/test/java/com/clickhouse/jdbc/WriterStatementImplTest.java

@@ -12,7 +12,7 @@
 
 @Test(groups = {"integration"})
 public class WriterStatementImplTest extends JdbcIntegrationTest {
-    
+
 
     @Test(groups = {"integration"})
     public void testTargetTypeMethodThrowException() throws SQLException {

jdbc-v2/src/test/java/com/clickhouse/jdbc/internal/SqlParserTest.java

@@ -247,8 +247,8 @@ public static Object[][] testCTEStmtsDP() {
                 {"(with a as (select ?) select * from a);", 1},
                 {"with a as (select 1) select * from a; ", 0},
                 {"(with ? as a select a);", 1},
-                {"select * from ( with x as ( select 9 ) select * from x );", 0}
-
+                {"select * from ( with x as ( select 9 ) select * from x );", 0},
+                {"WITH toDateTime(?) AS target_time SELECT * FROM table", 1}
         };
     }