public void test_get_primary_keys() throws SQLException {
    Object[][] testData = new Object[12][6];
    int testDataIndex = 0;
    Connection conn = DriverManager.getConnection("jdbc:duckdb:");
    String catalog = conn.getCatalog();
    Statement stmt = conn.createStatement();
    for (int schemaNumber = 1; schemaNumber <= 2; schemaNumber++) {
      String schemaName = "schema" + schemaNumber;
      stmt.executeUpdate("CREATE SCHEMA " + schemaName);
      stmt.executeUpdate("SET SCHEMA = '" + schemaName + "'");
      for (int tableNumber = 1; tableNumber <= 3; tableNumber++) {
        String tableName = "table" + tableNumber;
        String columns = null;
        String pk = null;
        for (int columnNumber = 1; columnNumber <= tableNumber; columnNumber++) {
          String columnName = "column" + columnNumber;
          String columnDef = columnName + " int not null";
          columns = columns == null ? columnDef : columns + "," + columnDef;
          pk = pk == null ? columnName : pk + "," + columnName;
          testData[testDataIndex++] = new Object[] {
            catalog,
            schemaName,
            tableName,
            columnName,
            columnNumber,
            null
          };
        }
        stmt.executeUpdate(
          "CREATE TABLE " + tableName + "(" + columns + 
          ",PRIMARY KEY(" + pk + ") )"
        );
      }
    }
    StringWriter sw = new StringWriter();
    PrintWriter pw = new PrintWriter(sw);
    pw.println("WITH constraint_columns as (");
    pw.println("select");
    pw.println("  database_name as \"TABLE_CAT\"");
    pw.println(", schema_name as \"TABLE_SCHEM\"");
    pw.println(", table_name as \"TABLE_NAME\"");
    pw.println(", unnest(constraint_column_names) as \"COLUMN_NAME\"");
    pw.println(", cast(null as varchar) as \"PK_NAME\"");
    pw.println("from duckdb_constraints");
    pw.println("where constraint_type = 'PRIMARY KEY'");
    pw.println(")");
    pw.println("SELECT \"TABLE_CAT\"");
    pw.println(", \"TABLE_SCHEM\"");
    pw.println(", \"TABLE_NAME\"");
    pw.println(", \"COLUMN_NAME\"");
    pw.println(", cast(row_number() over ");
    pw.println("(partition by \"TABLE_CAT\", \"TABLE_SCHEM\", \"TABLE_NAME\") as int) as \"KEY_SEQ\"");
    pw.println(", \"PK_NAME\"");
    pw.println("FROM constraint_columns");
    pw.println("ORDER BY TABLE_CAT, TABLE_SCHEM, TABLE_NAME, KEY_SEQ");
    
    ResultSet resultSet = stmt.executeQuery(sw.toString());
    for (testDataIndex = 0; testDataIndex < testData.length; testDataIndex++) {
      assertTrue("Expected a row at position " + testDataIndex, resultSet.next());
      Object[] testDataRow = testData[testDataIndex];
      for (int columnIndex = 0; columnIndex < testDataRow.length; columnIndex++) {
        Object value = testDataRow[columnIndex];
        if (value == null || value instanceof String) {
          String columnValue = resultSet.getString(columnIndex + 1);
          assertTrue(
            "row value " + testDataIndex + ", " + columnIndex + 
            " " + value + " should equal column value " + columnValue, 
            value == null ? columnValue == null : value.equals(columnValue)
          );
        }
        else {
          int testValue = ((Integer)value).intValue();
          int columnValue = resultSet.getInt(columnIndex + 1);
          assertTrue(
            "row value " + testDataIndex + ", " + columnIndex + 
            " " + testValue + " should equal column value " + columnValue,
            testValue == columnValue
          );
        }
      }
    }    
  }