retrieveEntity.sql

/*
 * ** header v3.0
 * This file is a part of the CaosDB Project.
 *
 * Copyright (C) 2018 Research Group Biomedical Physics,
 * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
 * Copyright (C) 2020 IndiScale GmbH <info@indiscale.com>
 * Copyright (C) 2020 Timm Fitschen <t.fitschen@indiscale
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 *
 * ** end header
 */



delimiter //

drop procedure if exists db_5_0.retrieveEntity //

/**
 * Select the content of an entity.
 *
 * By default the head is selected, but a specific version may be given.
 *
 * Parameters
 * ----------
 * EntityID
 *   The entity's id.
 * Version
 *   The version id.  In this procedure only, the version may also be given as
 *   `HEAD` for the latest version or as `HEAD~n`, which retrieves the n-th
 *   ancestor of `HEAD`.
 *
 * ResultSet
 * ---------
 * Tuple of (Datatype, Collection, EntityID, EntityName, EntityDesc,
 *           EntityRole, FileSize, FilePath, FileHash, ACL, Version)
 */
create procedure db_5_0.retrieveEntity(
    in EntityID INT UNSIGNED,
    in Version VARBINARY(255))
retrieveEntityBody: BEGIN
    DECLARE FilePath VARCHAR(255) DEFAULT NULL;
    DECLARE FileSize VARCHAR(255) DEFAULT NULL;
    DECLARE FileHash VARCHAR(255) DEFAULT NULL;
    DECLARE DatatypeID INT UNSIGNED DEFAULT NULL;
    DECLARE CollectionName VARCHAR(255) DEFAULT NULL;
    DECLARE IsHead BOOLEAN DEFAULT TRUE;
    DECLARE IVersion INT UNSIGNED DEFAULT NULL;
    DECLARE InternalEntityID INT UNSIGNED DEFAULT NULL;

    SELECT internal_id INTO InternalEntityID from entity_ids WHERE id = EntityID;

    IF InternalEntityID IS NULL THEN
        -- RETURN EARLY - Entity does not exist.
        SELECT 0 FROM entities WHERE 0 = 1;
        LEAVE retrieveEntityBody;
    END IF;