Ferreteria/v0.42/sql/node

versions: 0.41, 0.42, 0.5

About

• table purpose: root for all data
• record purpose: a thing that has values
• Module: Template:L/version

Concept

Every node

• is a record in the node table
• can have zero or more leafs
  • There's generally no point to having zero, but no reason to forbid it.
• can have a (node) type which points to a handler-class
  • so that when we're looking at a group of unspecified nodes, we know how to handle each one

History

• 2017-03-12 started
• 2017-04-09 decided there really should be a WhenMade timestamp; can always remove later
• 2017-08-05 renamed Class to Type for consistency with tf_leaf: records use "types", code maps these to "classes"
• 2020-01-16 redesigning for v0.4 (copied from Ferreteria/sql/tf node)
• 2020-01-23 copying from v0.41 to v0.42 essentially unaltered
• 2020-05-26 decided to remove NOT NULL from Type user can create new Nodes without any input.
  • Strongly inclined to make Type a pseudofield (Leaf), in any case.
• 2021-01-19
  • "integer width is deprecated"; also decided it should be 8 bytes
  • added ID_Mom because it seems necessary to be able to support sub-nodes

Fields

• Type: name of node type; code should know how to map these to node-handler classes

SQL

CREATE TABLE `node` (
  `ID`       BIGINT           NOT NULL AUTO_INCREMENT,
  `ID_Mom`   BIGINT       DEFAULT NULL COMMENT "ID of parent node, if any",
  `Type`     VARCHAR(255) DEFAULT NULL COMMENT "name of node type",
  `WhenMade` DATETIME         NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY(`ID`)
) ENGINE=InnoDB;