fix(update): skips update when nothing to update (#10248)

lib/model.js

@@ -2975,11 +2975,19 @@ class Model {
         });
       }
     }).then(results => {
+      // Update already done row-by-row - exit
       if (results) {
-        // Update already done row-by-row - exit
         return [results.length, results];
       }
 
+      // only updatedAt is being passed, then skip update
+      if (
+        _.isEmpty(valuesUse)
+         || Object.keys(valuesUse).length === 1 && valuesUse[this._timestampAttributes.updatedAt]
+      ) {
+        return [0];
+      }
+
       valuesUse = Utils.mapValueFieldNames(valuesUse, options.fields, this);
       options = Utils.mapOptionFieldNames(options, this);
       options.hasTrigger =  this.options ? this.options.hasTrigger : false;

test/integration/model/update.test.js

@@ -3,6 +3,7 @@
 const Support = require('../support');
 const DataTypes = require('../../../lib/data-types');
 const chai = require('chai');
+const sinon = require('sinon');
 const expect = chai.expect;
 const current = Support.sequelize;
 const _ = require('lodash');
@@ -35,6 +36,59 @@ describe(Support.getTestDialectTeaser('Model'), () => {
         }));
     });
 
+    describe('skips update query', () => {
+      it('if no data to update', function() {
+        const spy = sinon.spy();
+
+        return this.Account.create({ ownerId: 3 }).then(() => {
+          return this.Account.update({
+            unknownField: 'haha'
+          }, {
+            where: {
+              ownerId: 3
+            },
+            logging: spy
+          });
+        }).then(result => {
+          expect(result[0]).to.equal(0);
+          expect(spy.called, 'Update query was issued when no data to update').to.be.false;
+        });
+      });
+
+      it('skips when timestamps disabled', function() {
+        const Model = this.sequelize.define('Model', {
+          ownerId: {
+            type: DataTypes.INTEGER,
+            allowNull: false,
+            field: 'owner_id'
+          },
+          name: {
+            type: DataTypes.STRING
+          }
+        }, {
+          timestamps: false
+        });
+        const spy = sinon.spy();
+
+        return Model.sync({ force: true })
+          .then(() => Model.create({ ownerId: 3 }))
+          .then(() => {
+            return Model.update({
+              unknownField: 'haha'
+            }, {
+              where: {
+                ownerId: 3
+              },
+              logging: spy
+            });
+          })
+          .then(result => {
+            expect(result[0]).to.equal(0);
+            expect(spy.called, 'Update query was issued when no data to update').to.be.false;
+          });
+      });
+    });
+
     it('changed should be false after reload', function() {
       return this.Account.create({ ownerId: 2, name: 'foo' })
         .then(account => {