fix(postgres/createSchema): support for create schema if not exists w… (#8484)

lib/dialects/postgres/query-generator.js

@@ -17,6 +17,12 @@ const QueryGenerator = {
   },
 
   createSchema(schema) {
+    const databaseVersion = _.get(this, 'sequelize.options.databaseVersion', 0);
+
+    if (databaseVersion && semver.gte(databaseVersion, '9.2.0')) {
+      return `CREATE SCHEMA IF NOT EXISTS ${schema};`;
+    }
+
     return `CREATE SCHEMA ${schema};`;
   },
 

test/integration/dialects/postgres/query-interface.test.js

@@ -34,10 +34,17 @@ if (dialect.match(/^postgres/)) {
           });
       });
 
-      it('errors if the schema exists', function() {
+      it('works even when schema exists', function() {
         return this.queryInterface.createSchema('testschema')
-          .catch(err => {
-            expect(err.message).to.be.equal('schema "testschema" already exists');
+          .then(() => this.queryInterface.createSchema('testschema'))
+          .then(() => this.sequelize.query(`
+            SELECT schema_name
+            FROM information_schema.schemata
+            WHERE schema_name = 'testschema';
+          `, { type: this.sequelize.QueryTypes.SELECT }))
+          .then(res => {
+            expect(res, 'query results').to.not.be.empty;
+            expect(res[0].schema_name).to.be.equal('testschema');
           });
       });
     });

test/integration/model/searchPath.test.js

 'use strict';
 
-const chai = require('chai'),
-  expect = chai.expect,
-  Support = require(__dirname + '/../support'),
-  DataTypes = require(__dirname + '/../../../lib/data-types');
+const chai = require('chai');
+const expect = chai.expect;
+const Support = require(__dirname + '/../support');
+const DataTypes = require(__dirname + '/../../../lib/data-types');
+
 const SEARCH_PATH_ONE = 'schema_one,public';
 const SEARCH_PATH_TWO = 'schema_two,public';
 

test/unit/sql/create-schema.test.js

 'use strict';
 
-const Support   = require(__dirname + '/../support'),
-  expectsql = Support.expectsql,
-  current   = Support.sequelize,
-  sql       = current.dialect.QueryGenerator;
+const Support = require(__dirname + '/../support');
+const expectsql = Support.expectsql;
+const current = Support.sequelize;
+const sql = current.dialect.QueryGenerator;
 
 describe(Support.getTestDialectTeaser('SQL'), () => {
   if (current.dialect.name === 'postgres') {
     describe('dropSchema', () => {
-      test('IF EXISTS', () => {
+      it('IF EXISTS', () => {
         expectsql(sql.dropSchema('foo'), {
           postgres: 'DROP SCHEMA IF EXISTS foo CASCADE;'
         });
       });
     });
+
+    describe('createSchema', () => {
+      before(function () {
+        this.version = current.options.databaseVersion;
+      });
+
+      after(function () {
+        current.options.databaseVersion = this.version;
+      });
+
+      it('9.2.0 or above', () => {
+        current.options.databaseVersion = '9.2.0';
+        expectsql(sql.createSchema('foo'), {
+          postgres: 'CREATE SCHEMA IF NOT EXISTS foo;'
+        });
+      });
+
+      it('below 9.2.0', () => {
+        current.options.databaseVersion = '9.0.0';
+        expectsql(sql.createSchema('foo'), {
+          postgres: 'CREATE SCHEMA foo;'
+        });
+      });
+    });
   }
 });