sequelize/lib/associations/helpers.js

Sequelize is a promise-based Node.js ORM tool for Postgres, MySQL, MariaDB, SQLite, Microsoft SQL Server, Amazon Redshift and Snowflake’s Data Cloud. It features solid transaction support, relations, eager and lazy loading, read replication and more.

'use strict';

function checkNamingCollision(association) {
  if (Object.prototype.hasOwnProperty.call(association.source.rawAttributes, association.as)) {
    throw new Error(
      `Naming collision between attribute '${association.as}'` +
      ` and association '${association.as}' on model ${association.source.name}` +
      '. To remedy this, change either foreignKey or as in your association definition'
    );
  }
}
exports.checkNamingCollision = checkNamingCollision;

function addForeignKeyConstraints(newAttribute, source, target, options, key) {
  // FK constraints are opt-in: users must either set `foreignKeyConstraints`
  // on the association, or request an `onDelete` or `onUpdate` behavior

  if (options.foreignKeyConstraint || options.onDelete || options.onUpdate) {
    // Find primary keys: composite keys not supported with this approach
    const primaryKeys = Object.keys(source.primaryKeys)
      .map(primaryKeyAttribute => source.rawAttributes[primaryKeyAttribute].field || primaryKeyAttribute);

    if (primaryKeys.length === 1 || !primaryKeys.includes(key)) {
      newAttribute.references = {
        model: source.getTableName(),
        key: key || primaryKeys[0]
      };

      newAttribute.onDelete = options.onDelete;
      newAttribute.onUpdate = options.onUpdate;
    }
  }
}
exports.addForeignKeyConstraints = addForeignKeyConstraints;

/**
 * Mixin (inject) association methods to model prototype
 *
 * @private
 *
 * @param {object} association instance
 * @param {object} obj Model prototype
 * @param {Array} methods Method names to inject
 * @param {object} aliases Mapping between model and association method names
 *
 */
function mixinMethods(association, obj, methods, aliases) {
  aliases = aliases || {};

  for (const method of methods) {
    // don't override custom methods
    if (!Object.prototype.hasOwnProperty.call(obj, association.accessors[method])) {
      const realMethod = aliases[method] || method;

      obj[association.accessors[method]] = function() {
        return association[realMethod](this, ...Array.from(arguments));
      };
    }
  }
}
exports.mixinMethods = mixinMethods;