private Pair getCatalogSchema()

in wayang-api/wayang-api-sql/src/main/java/org/apache/wayang/api/sql/calcite/jdbc/JdbcSchema.java [294:325]

• 30 lines of code
• 10 McCabe index (conditional complexity)

  private Pair<@Nullable String, @Nullable String> getCatalogSchema(Connection connection)
      throws SQLException {
    final DatabaseMetaData metaData = connection.getMetaData();
    final List<Integer> version41 = ImmutableList.of(4, 1); // JDBC 4.1
    String catalog = this.catalog;
    String schema = this.schema;
    final boolean jdbc41OrAbove =
        VERSION_ORDERING.compare(version(metaData), version41) >= 0;
    if (catalog == null && jdbc41OrAbove) {
      // From JDBC 4.1, catalog and schema can be retrieved from the connection
      // object, hence try to get it from there if it was not specified by user
      catalog = connection.getCatalog();
    }
    if (schema == null && jdbc41OrAbove) {
      schema = connection.getSchema();
      if ("".equals(schema)) {
        schema = null; // PostgreSQL returns useless "" sometimes
      }
    }
    if ((catalog == null || schema == null)
        && metaData.getDatabaseProductName().equals("PostgreSQL")) {
      final String sql = "select current_database(), current_schema()";
      try (Statement statement = connection.createStatement();
           ResultSet resultSet = statement.executeQuery(sql)) {
        if (resultSet.next()) {
          catalog = resultSet.getString(1);
          schema = resultSet.getString(2);
        }
      }
    }
    return Pair.of(catalog, schema);
  }