How to use

aliased

method

in

io.prestosql.sql.QueryUtil

@Override
protected Node visitShowCatalogs(ShowCatalogs node, Void context)
{
  List<Expression> rows = listCatalogs(session, metadata, accessControl).keySet().stream()
      .map(name -> row(new StringLiteral(name)))
      .collect(toList());
  Optional<Expression> predicate = Optional.empty();
  Optional<String> likePattern = node.getLikePattern();
  if (likePattern.isPresent()) {
    predicate = Optional.of(new LikePredicate(identifier("Catalog"), new StringLiteral(likePattern.get()), Optional.empty()));
  }
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(new Values(rows), "catalogs", ImmutableList.of("Catalog")),
      predicate,
      Optional.of(ordering(ascending("Catalog"))));
}

    aliasedName("type", "Type"),
    aliasedName("description", "Description")),
aliased(
    new Values(rows.build()),
    "session",

@Override
protected Node visitShowCatalogs(ShowCatalogs node, Void context)
{
  List<Expression> rows = listCatalogs(session, metadata, accessControl).keySet().stream()
      .map(name -> row(new StringLiteral(name)))
      .collect(toList());
  Optional<Expression> predicate = Optional.empty();
  Optional<String> likePattern = node.getLikePattern();
  if (likePattern.isPresent()) {
    predicate = Optional.of(new LikePredicate(identifier("Catalog"), new StringLiteral(likePattern.get()), Optional.empty()));
  }
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(new Values(rows), "catalogs", ImmutableList.of("Catalog")),
      predicate,
      Optional.of(ordering(ascending("Catalog"))));
}

    .map(entry -> aliasedName(entry.getKey(), entry.getValue()))
    .collect(toImmutableList())),
aliased(new Values(rows.build()), "functions", ImmutableList.copyOf(columns.keySet())),
ordering(
    new SortItem(

public static Query singleValueQuery(String columnName, boolean value)
{
  Relation values = values(row(value ? TRUE_LITERAL : FALSE_LITERAL));
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(values, "t", ImmutableList.of(columnName)));
}

    aliasedName("type", "Type"),
    aliasedName("description", "Description")),
aliased(
    new Values(rows.build()),
    "session",

public static Query singleValueQuery(String columnName, boolean value)
{
  Relation values = values(row(value ? TRUE_LITERAL : FALSE_LITERAL));
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(values, "t", ImmutableList.of(columnName)));
}

    .map(entry -> aliasedName(entry.getKey(), entry.getValue()))
    .collect(toImmutableList())),
aliased(new Values(rows.build()), "functions", ImmutableList.copyOf(columns.keySet())),
ordering(
    new SortItem(

public static Query singleValueQuery(String columnName, String value)
{
  Relation values = values(row(new StringLiteral((value))));
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(values, "t", ImmutableList.of(columnName)));
}

public static Query singleValueQuery(String columnName, String value)
{
  Relation values = values(row(new StringLiteral((value))));
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(values, "t", ImmutableList.of(columnName)));
}

@Override
protected Node visitShowRoleGrants(ShowRoleGrants node, Void context)
{
  if (!node.getCatalog().isPresent() && !session.getCatalog().isPresent()) {
    throw new SemanticException(CATALOG_NOT_SPECIFIED, node, "Catalog must be specified when session catalog is not set");
  }
  String catalog = node.getCatalog().map(c -> c.getValue().toLowerCase(ENGLISH)).orElseGet(() -> session.getCatalog().get());
  PrestoPrincipal principal = new PrestoPrincipal(PrincipalType.USER, session.getUser());
  accessControl.checkCanShowRoleGrants(session.getRequiredTransactionId(), session.getIdentity(), catalog);
  List<Expression> rows = metadata.listRoleGrants(session, catalog, principal).stream()
      .map(roleGrant -> row(new StringLiteral(roleGrant.getRoleName())))
      .collect(toList());
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(new Values(rows), "role_grants", ImmutableList.of("Role Grants")),
      ordering(ascending("Role Grants")));
}

@Override
protected Node visitShowRoleGrants(ShowRoleGrants node, Void context)
{
  if (!node.getCatalog().isPresent() && !session.getCatalog().isPresent()) {
    throw new SemanticException(CATALOG_NOT_SPECIFIED, node, "Catalog must be specified when session catalog is not set");
  }
  String catalog = node.getCatalog().map(c -> c.getValue().toLowerCase(ENGLISH)).orElseGet(() -> session.getCatalog().get());
  PrestoPrincipal principal = new PrestoPrincipal(PrincipalType.USER, session.getUser());
  accessControl.checkCanShowRoleGrants(session.getRequiredTransactionId(), session.getIdentity(), catalog);
  List<Expression> rows = metadata.listRoleGrants(session, catalog, principal).stream()
      .map(roleGrant -> row(new StringLiteral(roleGrant.getRoleName())))
      .collect(toList());
  return simpleQuery(
      selectList(new AllColumns()),
      aliased(new Values(rows), "role_grants", ImmutableList.of("Role Grants")),
      ordering(ascending("Role Grants")));
}

@Override
protected Node visitDescribeInput(DescribeInput node, Void context)
    throws SemanticException
{
  String sqlString = session.getPreparedStatement(node.getName().getValue());
  Statement statement = parser.createStatement(sqlString, createParsingOptions(session));
  // create  analysis for the query we are describing.
  Analyzer analyzer = new Analyzer(session, metadata, parser, accessControl, queryExplainer, parameters, warningCollector);
  Analysis analysis = analyzer.analyze(statement, true);
  // get all parameters in query
  List<Parameter> parameters = getParameters(statement);
  // return the positions and types of all parameters
  Row[] rows = parameters.stream().map(parameter -> createDescribeInputRow(parameter, analysis)).toArray(Row[]::new);
  Optional<String> limit = Optional.empty();
  if (rows.length == 0) {
    rows = new Row[] {row(new NullLiteral(), new NullLiteral())};
    limit = Optional.of("0");
  }
  return simpleQuery(
      selectList(identifier("Position"), identifier("Type")),
      aliased(
          values(rows),
          "Parameter Input",
          ImmutableList.of("Position", "Type")),
      Optional.empty(),
      Optional.empty(),
      Optional.empty(),
      Optional.of(ordering(ascending("Position"))),
      limit);
}

@Override
protected Node visitDescribeInput(DescribeInput node, Void context)
    throws SemanticException
{
  String sqlString = session.getPreparedStatement(node.getName().getValue());
  Statement statement = parser.createStatement(sqlString, createParsingOptions(session));
  // create  analysis for the query we are describing.
  Analyzer analyzer = new Analyzer(session, metadata, parser, accessControl, queryExplainer, parameters, warningCollector);
  Analysis analysis = analyzer.analyze(statement, true);
  // get all parameters in query
  List<Parameter> parameters = getParameters(statement);
  // return the positions and types of all parameters
  Row[] rows = parameters.stream().map(parameter -> createDescribeInputRow(parameter, analysis)).toArray(Row[]::new);
  Optional<String> limit = Optional.empty();
  if (rows.length == 0) {
    rows = new Row[] {row(new NullLiteral(), new NullLiteral())};
    limit = Optional.of("0");
  }
  return simpleQuery(
      selectList(identifier("Position"), identifier("Type")),
      aliased(
          values(rows),
          "Parameter Input",
          ImmutableList.of("Position", "Type")),
      Optional.empty(),
      Optional.empty(),
      Optional.empty(),
      Optional.of(ordering(ascending("Position"))),
      limit);
}

    identifier("Type Size"),
    identifier("Aliased")),
aliased(
    values(rows),
    "Statement Output",

    identifier("Type Size"),
    identifier("Aliased")),
aliased(
    values(rows),
    "Statement Output",

private Node rewriteShowStats(ShowStats node, Table table, Constraint<ColumnHandle> constraint)
{
  TableHandle tableHandle = getTableHandle(node, table.getName());
  TableStatistics tableStatistics = metadata.getTableStatistics(session, tableHandle, constraint);
  List<String> statsColumnNames = buildColumnsNames();
  List<SelectItem> selectItems = buildSelectItems(statsColumnNames);
  TableMetadata tableMetadata = metadata.getTableMetadata(session, tableHandle);
  Map<String, ColumnHandle> columnHandles = metadata.getColumnHandles(session, tableHandle);
  List<Expression> resultRows = buildStatisticsRows(tableMetadata, columnHandles, tableStatistics);
  return simpleQuery(selectAll(selectItems),
      aliased(new Values(resultRows),
          "table_stats_for_" + table.getName(),
          statsColumnNames));
}

private Node rewriteShowStats(ShowStats node, Table table, Constraint<ColumnHandle> constraint)
{
  TableHandle tableHandle = getTableHandle(node, table.getName());
  TableStatistics tableStatistics = metadata.getTableStatistics(session, tableHandle, constraint);
  List<String> statsColumnNames = buildColumnsNames();
  List<SelectItem> selectItems = buildSelectItems(statsColumnNames);
  TableMetadata tableMetadata = metadata.getTableMetadata(session, tableHandle);
  Map<String, ColumnHandle> columnHandles = metadata.getColumnHandles(session, tableHandle);
  List<Expression> resultRows = buildStatisticsRows(tableMetadata, columnHandles, tableStatistics);
  return simpleQuery(selectAll(selectItems),
      aliased(new Values(resultRows),
          "table_stats_for_" + table.getName(),
          statsColumnNames));
}