Merge pull request #743 from percyperez/master

Enforce referential integrity data-model example

examples/enforce-referential-integrity/app.js

+/*jslint node:true */
+"use strict";
+
+var Sequelize = require('sequelize');
+
+// initialize database connection
+var sequelize = new Sequelize('testsequelize', 'testsequelize', 'testsequelize', {
+    dialect: 'postgres',
+    port: 5432,
+    define: {
+        freezeTableName: true
+    }
+});
+
+// load models
+var models = [
+    'Trainer',
+    'Series',
+    'Video'
+];
+
+models.forEach(function(model) {
+    module.exports[model] = sequelize.import(__dirname + '/' + model);
+});
+
+// describe relationships
+(function(m) {
+    m.Series.hasOne(m.Video);
+    m.Trainer.hasMany(m.Series);
+})(module.exports);
+
+// export connection
+module.exports.sequelize = sequelize;
\ No newline at end of file

examples/enforce-referential-integrity/models/Series.js

+/*jslint node:true */
+"use strict";
+
+module.exports = function(sequelize, DataTypes) {
+    return sequelize.define('Series', {
+        title: {
+            type: DataTypes.STRING
+        },
+        sub_title: {
+            type: DataTypes.STRING
+        },
+        description: {
+            type: DataTypes.TEXT
+        },
+        // Set FK relationship (hasMany) with `Trainer`
+        trainer_id: {
+            type: DataTypes.INTEGER,
+            references: "Trainer",
+            referencesKey: 'id'
+        }
+    }, {
+        // don't need timestamp attributes for this model
+        timestamps: false,
+        underscored: true
+    });
+};

examples/enforce-referential-integrity/models/Trainer.js

+/*jslint node:true */
+"use strict";
+
+module.exports = function(sequelize, DataTypes) {
+    return sequelize.define('Trainer', {
+        first_name: {
+            type: DataTypes.STRING
+        },
+        last_name: {
+            type: DataTypes.STRING
+        }
+    }, {
+        // don't need timestamp attributes for this model
+        timestamps: false,
+        underscored: true
+    });
+};

examples/enforce-referential-integrity/models/Video.js

+/*jslint node:true */
+"use strict";
+
+module.exports = function(sequelize, DataTypes) {
+    return sequelize.define('Video', {
+        title: {
+            type: DataTypes.STRING
+        },
+        sequence: {
+            type: DataTypes.INTEGER
+        },
+        description: {
+            type: DataTypes.TEXT
+        },
+        // set relationship (hasOne) with `Series`
+        series_id: {
+            type: DataTypes.INTEGER,
+            references: "Series",
+            referencesKey: 'id'
+        }
+    }, {
+        // don't need timestamp attributes for this model
+        timestamps: false,
+        underscored: true
+    });
+};

examples/enforce-referential-integrity/results.md

+Results after syncing the dabatase
+----------------------------------
+
+After syncing the database, you'll see in the console the following:
+
+```
+Executing: CREATE TABLE IF NOT EXISTS "Trainer" ("first_name" VARCHAR(255), "last_name" VARCHAR(255), "id"   SERIAL , PRIMARY KEY ("id"));
+Executing: CREATE TABLE IF NOT EXISTS "Series" ("title" VARCHAR(255), "sub_title" VARCHAR(255), "description" TEXT, "trainer_id" INTEGER REFERENCES "Trainer" ("id"), "id"   SERIAL , PRIMARY KEY ("id"));
+Executing: CREATE TABLE IF NOT EXISTS "Video" ("title" VARCHAR(255), "sequence" INTEGER, "description" TEXT, "series_id" INTEGER REFERENCES "Series" ("id"), "id"   SERIAL , PRIMARY KEY ("id"));
+```
+
+Notice in the `Video` that `series_id` field has a referential integrity to `Series`:
+
+```
+"series_id" INTEGER REFERENCES "Series" ("id")
+```
+
+This is the output when describing the table's structure of the Postgres database:
+
+**Trainer** table:
+```
+testsequelize=> \d+ "Trainer";
+                                                        Table "public.Trainer"
+   Column   |          Type          |                       Modifiers                        |
+------------+------------------------+--------------------------------------------------------+
+ first_name | character varying(255) |                                                        |
+ last_name  | character varying(255) |                                                        |
+ id         | integer                | not null default nextval('"Trainer_id_seq"'::regclass) |
+Indexes:
+    "Trainer_pkey" PRIMARY KEY, btree (id)
+Referenced by:
+    TABLE ""Series"" CONSTRAINT "Series_trainer_id_fkey" FOREIGN KEY (trainer_id) REFERENCES "Trainer"(id)
+Has OIDs: no
+```
+
+**Series** table:
+```
+testsequelize=> \d+ "Series";
+                                                          Table "public.Series"
+     Column      |          Type          |                       Modifiers                       |
+-----------------+------------------------+-------------------------------------------------------+
+ title           | character varying(255) |                                                       |
+ sub_title       | character varying(255) |                                                       |
+ description     | text                   |                                                       |
+ trainer_id      | integer                |                                                       |
+ id              | integer                | not null default nextval('"Series_id_seq"'::regclass) |
+Indexes:
+    "Series_pkey" PRIMARY KEY, btree (id)
+Foreign-key constraints:
+    "Series_trainer_id_fkey" FOREIGN KEY (trainer_id) REFERENCES "Trainer"(id)
+Referenced by:
+    TABLE ""Video"" CONSTRAINT "Video_series_id_fkey" FOREIGN KEY (series_id) REFERENCES "Series"(id)
+Has OIDs: no
+```
+
+**Video** table:
+```
+testsequelize=> \d+ "Video";
+                                                        Table "public.Video"
+   Column    |          Type          |                      Modifiers                       |
+-------------+------------------------+------------------------------------------------------+
+ title       | character varying(255) |                                                      |
+ sequence    | integer                |                                                      |
+ description | text                   |                                                      |
+ series_id   | integer                |                                                      |
+ id          | integer                | not null default nextval('"Video_id_seq"'::regclass) |
+Indexes:
+    "Video_pkey" PRIMARY KEY, btree (id)
+Foreign-key constraints:
+    "Video_series_id_fkey" FOREIGN KEY (series_id) REFERENCES "Series"(id)
+Has OIDs: no
+```