How to use

equal

method

in

io.prestosql.sql.QueryUtil

@Override
protected Node visitShowColumns(ShowColumns showColumns, Void context)
{
  QualifiedObjectName tableName = createQualifiedObjectName(session, showColumns, showColumns.getTable());
  if (!metadata.getView(session, tableName).isPresent() &&
      !metadata.getTableHandle(session, tableName).isPresent()) {
    throw new SemanticException(MISSING_TABLE, showColumns, "Table '%s' does not exist", tableName);
  }
  return simpleQuery(
      selectList(
          aliasedName("column_name", "Column"),
          aliasedName("data_type", "Type"),
          aliasedNullToEmpty("extra_info", "Extra"),
          aliasedNullToEmpty("comment", "Comment")),
      from(tableName.getCatalogName(), TABLE_COLUMNS),
      logicalAnd(
          equal(identifier("table_schema"), new StringLiteral(tableName.getSchemaName())),
          equal(identifier("table_name"), new StringLiteral(tableName.getObjectName()))),
      ordering(ascending("ordinal_position")));
}

@Override
protected Node visitShowColumns(ShowColumns showColumns, Void context)
{
  QualifiedObjectName tableName = createQualifiedObjectName(session, showColumns, showColumns.getTable());
  if (!metadata.getView(session, tableName).isPresent() &&
      !metadata.getTableHandle(session, tableName).isPresent()) {
    throw new SemanticException(MISSING_TABLE, showColumns, "Table '%s' does not exist", tableName);
  }
  return simpleQuery(
      selectList(
          aliasedName("column_name", "Column"),
          aliasedName("data_type", "Type"),
          aliasedNullToEmpty("extra_info", "Extra"),
          aliasedNullToEmpty("comment", "Comment")),
      from(tableName.getCatalogName(), TABLE_COLUMNS),
      logicalAnd(
          equal(identifier("table_schema"), new StringLiteral(tableName.getSchemaName())),
          equal(identifier("table_name"), new StringLiteral(tableName.getObjectName()))),
      ordering(ascending("ordinal_position")));
}

equal(identifier("table_schema"), new StringLiteral(qualifiedTableName.getSchemaName())),
equal(identifier("table_name"), new StringLiteral(qualifiedTableName.getObjectName()))));

equal(identifier("table_schema"), new StringLiteral(qualifiedTableName.getSchemaName())),
equal(identifier("table_name"), new StringLiteral(qualifiedTableName.getObjectName()))));

@Override
protected Node visitShowTables(ShowTables showTables, Void context)
{
  CatalogSchemaName schema = createCatalogSchemaName(session, showTables, showTables.getSchema());
  accessControl.checkCanShowTablesMetadata(session.getRequiredTransactionId(), session.getIdentity(), schema);
  if (!metadata.catalogExists(session, schema.getCatalogName())) {
    throw new SemanticException(MISSING_CATALOG, showTables, "Catalog '%s' does not exist", schema.getCatalogName());
  }
  if (!metadata.schemaExists(session, schema)) {
    throw new SemanticException(MISSING_SCHEMA, showTables, "Schema '%s' does not exist", schema.getSchemaName());
  }
  Expression predicate = equal(identifier("table_schema"), new StringLiteral(schema.getSchemaName()));
  Optional<String> likePattern = showTables.getLikePattern();
  if (likePattern.isPresent()) {
    Expression likePredicate = new LikePredicate(
        identifier("table_name"),
        new StringLiteral(likePattern.get()),
        showTables.getEscape().map(StringLiteral::new));
    predicate = logicalAnd(predicate, likePredicate);
  }
  return simpleQuery(
      selectList(aliasedName("table_name", "Table")),
      from(schema.getCatalogName(), TABLE_TABLES),
      predicate,
      ordering(ascending("table_name")));
}

@Override
protected Node visitShowTables(ShowTables showTables, Void context)
{
  CatalogSchemaName schema = createCatalogSchemaName(session, showTables, showTables.getSchema());
  accessControl.checkCanShowTablesMetadata(session.getRequiredTransactionId(), session.getIdentity(), schema);
  if (!metadata.catalogExists(session, schema.getCatalogName())) {
    throw new SemanticException(MISSING_CATALOG, showTables, "Catalog '%s' does not exist", schema.getCatalogName());
  }
  if (!metadata.schemaExists(session, schema)) {
    throw new SemanticException(MISSING_SCHEMA, showTables, "Schema '%s' does not exist", schema.getSchemaName());
  }
  Expression predicate = equal(identifier("table_schema"), new StringLiteral(schema.getSchemaName()));
  Optional<String> likePattern = showTables.getLikePattern();
  if (likePattern.isPresent()) {
    Expression likePredicate = new LikePredicate(
        identifier("table_name"),
        new StringLiteral(likePattern.get()),
        showTables.getEscape().map(StringLiteral::new));
    predicate = logicalAnd(predicate, likePredicate);
  }
  return simpleQuery(
      selectList(aliasedName("table_name", "Table")),
      from(schema.getCatalogName(), TABLE_TABLES),
      predicate,
      ordering(ascending("table_name")));
}