feat: migrations structure and example

Refs: #23

test/schema/.database.js

@@ -0,0 +1,16 @@
+({
+  name: 'example',
+  description: 'Example database schema',
+  version: 3,
+
+  authors: [
+    { name: 'Timur Shemsedinov', email: 'timur.shemsedinov@gmail.com' },
+  ],
+
+  extensions: [
+    'hstore',
+    'postgis',
+    'postgis_topology',
+    'pg_trgm',
+  ]
+});

test/schema/.history/2020-09-11-v1/.database.js

@@ -0,0 +1,14 @@
+({
+  name: 'example',
+  description: 'Example database schema',
+  version: 1,
+
+  authors: [
+    { name: 'Timur Shemsedinov', email: 'timur.shemsedinov@gmail.com' },
+  ],
+
+  extensions: [
+    'hstore',
+    'pg_trgm',
+  ]
+});

test/schema/.history/2020-09-11-v1/City.js

@@ -0,0 +1,4 @@
+({
+  country: 'Country',
+  name: { type: 'string', unique: true },
+});

test/schema/.history/2020-09-11-v1/Country.js

@@ -0,0 +1,3 @@
+({
+  name: { type: 'string', unique: true },
+});

test/schema/.history/2020-09-11-v2/.database.js

@@ -0,0 +1,14 @@
+({
+  name: 'example',
+  description: 'Example database schema',
+  version: 2,
+
+  authors: [
+    { name: 'Timur Shemsedinov', email: 'timur.shemsedinov@gmail.com' },
+  ],
+
+  extensions: [
+    'hstore',
+    'pg_trgm',
+  ]
+});

test/schema/.history/2020-09-11-v2/City.js

@@ -0,0 +1,4 @@
+({
+  country: 'Country',
+  name: { type: 'string', unique: true },
+});

test/schema/.history/2020-09-11-v2/Country.js

@@ -0,0 +1,4 @@
+({
+  planet: 'Planet',
+  name: { type: 'string', unique: true },
+});

test/schema/.history/2020-09-11-v2/District.js

@@ -0,0 +1,4 @@
+({
+  city: 'City',
+  name: 'string',
+});

test/schema/.history/2020-09-11-v2/Planet.js

@@ -0,0 +1,3 @@
+({
+  name: 'string',
+});

test/schema/.migrations/2020-09-11-v1-dn.sql

@@ -0,0 +1,5 @@
+DROP TABLE "Country";
+DROP TABLE "City";
+
+DROP EXTENSION hstore;
+DROP EXTENSION pg_trgm;

test/schema/.migrations/2020-09-11-v1-up.sql

@@ -0,0 +1,20 @@
+CREATE EXTENSION hstore;
+CREATE EXTENSION pg_trgm;
+
+CREATE TABLE "Country" (
+  "countryId" bigint generated always as identity,
+  "name" varchar NOT NULL
+);
+
+ALTER TABLE "Country" ADD CONSTRAINT "pkCountry" PRIMARY KEY ("countryId");
+CREATE UNIQUE INDEX "akCountryName" ON "Country" ("name");
+
+CREATE TABLE "City" (
+  "cityId" bigint generated always as identity,
+  "countryId" bigint NOT NULL,
+  "name" varchar NOT NULL
+);
+
+ALTER TABLE "City" ADD CONSTRAINT "pkCity" PRIMARY KEY ("cityId");
+ALTER TABLE "City" ADD CONSTRAINT "fkCityCountry" FOREIGN KEY ("countryId") REFERENCES "Country" ("countryId") ON DELETE CASCADE;
+CREATE UNIQUE INDEX "akCityName" ON "City" ("name");

test/schema/.migrations/2020-09-11-v2-dn.sql

@@ -0,0 +1,5 @@
+DROP TABLE "District";
+
+ALTER TABLE "Country" DROP COLUMN "planetId";
+
+DROP TABLE "Planet";

test/schema/.migrations/2020-09-11-v2-up.sql

@@ -0,0 +1,19 @@
+CREATE TABLE "Planet" (
+  "planetId" bigint generated always as identity,
+  "name" varchar NOT NULL
+);
+
+ALTER TABLE "Planet" ADD CONSTRAINT "pkPlanet" PRIMARY KEY ("planetId");
+
+ALTER TABLE "Country" ADD COLUMN "planetId" bigint NOT NULL );
+
+ALTER TABLE "Country" ADD CONSTRAINT "fkCountryPlanet" FOREIGN KEY ("planetId") REFERENCES "Planet" ("planetId") ON DELETE CASCADE;
+
+CREATE TABLE "District" (
+  "districtId" bigint generated always as identity,
+  "cityId" bigint NOT NULL,
+  "name" varchar NOT NULL
+);
+
+ALTER TABLE "District" ADD CONSTRAINT "pkDistrict" PRIMARY KEY ("districtId");
+ALTER TABLE "District" ADD CONSTRAINT "fkDistrictCity" FOREIGN KEY ("cityId") REFERENCES "City" ("cityId") ON DELETE CASCADE;