Added UPDATE query

src/classes/insert.class.js

@@ -4,7 +4,7 @@ const { ValuesMixin } = require('../mixins');
 
 class Insert extends ValuesMixin(SpecificQuery) {
   get canExecute() {
-    return !is.null(this._values);
+    return is.not.null(this._values);
   }
 
   get query() {

src/classes/query.class.js

@@ -36,7 +36,7 @@ class Query {
    * @readonly
    */
   get canExecute() {
-    return !is.emptyString(this.query);
+    return is.not.emptyString(this.query);
   }
 
   /**

src/classes/select.class.js

@@ -12,7 +12,7 @@ class Select extends WhereMixin(
   OrderByMixin(OffsetMixin(LimitMixin(ColumnsMixin(SpecificQuery))))
 ) {
   get canExecute() {
-    return !is.null(this._columns);
+    return is.not.null(this._columns);
   }
 
   get query() {

src/classes/update.class.js

+const { is } = require('@creanet/js-type');
+const SpecificQuery = require('./query.specific.class');
+const { SetMixin, WhereMixin } = require('../mixins');
+
+class Update extends WhereMixin(SetMixin(SpecificQuery)) {
+  get canExecute() {
+    return is.not.null(this._set);
+  }
+
+  get query() {
+    return `UPDATE ${this.table} ${this.setSQL} ${this.whereSQL}`;
+  }
+}
+
+module.exports = Update;

src/database.class.js

@@ -3,6 +3,7 @@ const GenericQuery = require('./classes/query.specific.class');
 const Select = require('./classes/select.class');
 const Insert = require('./classes/insert.class');
 const Delete = require('./classes/delete.class');
+const Update = require('./classes/update.class');
 
 /**
  * Class for communication with PostgreSQL database
@@ -63,6 +64,17 @@ class Database {
   delete(table) {
     return new Delete(this, table);
   }
+
+  /**
+   * Creates an Update object
+   *
+   * @param {String} table
+   * @returns {Update} update
+   * @memberof Database
+   */
+  update(table) {
+    return new Update(this, table);
+  }
 }
 
 module.exports = Database;

src/mixins/columns.mixin.js

@@ -22,7 +22,7 @@ const ColumnsMixin = C =>
     columns(columns) {
       columns = force.array(columns);
 
-      if (!is.array(columns, 'string')) {
+      if (is.not.array(columns, 'string')) {
         throw TypeError('columns is of invalid type');
       }
 

src/mixins/index.js

@@ -4,5 +4,6 @@ module.exports = {
   OffsetMixin: require('./offset.mixin'),
   ValuesMixin: require('./values.mixin'),
   WhereMixin: require('./where.mixin'),
-  OrderByMixin: require('./order-by.mixin')
+  OrderByMixin: require('./order-by.mixin'),
+  SetMixin: require('./set.mixin')
 };

src/mixins/limit.mixin.js

@@ -22,7 +22,7 @@ const LimitMixin = C =>
      * @param {number} limit
      */
     limit(limit) {
-      if (!is.numeric(limit)) {
+      if (is.not.numeric(limit)) {
         throw TypeError('limit is of invalid type');
       }
 

src/mixins/offset.mixin.js

@@ -22,7 +22,7 @@ const OffsetMixin = C =>
      * @param {number} offset
      */
     offset(offset) {
-      if (!is.numeric(offset)) {
+      if (is.not.numeric(offset)) {
         throw TypeError('offset is of invalid type');
       }
 

src/mixins/order-by.mixin.js

@@ -23,7 +23,7 @@ const OrderByMixin = C =>
     orderBy(orderBy) {
       orderBy = force.array(orderBy);
 
-      if (!is.array(orderBy, 'keyValuePair')) {
+      if (is.not.array(orderBy, 'keyValuePair')) {
         throw TypeError('orderBy is of invalid type');
       }
 

src/mixins/set.mixin.js

+const { is, force } = require('@creanet/js-type');
+
+const SetMixin = C =>
+  class SetMixin extends C {
+    constructor() {
+      super(...arguments);
+      this._set = null;
+    }
+
+    get setSQL() {
+      const set = Object.entries(this._set)
+        .map(([key, value]) => `${key}='${value}'`)
+        .join(',');
+
+      return `SET ${set}`;
+    }
+
+    /**
+     * Sets the values of set. Valid values are:
+     * - `{Object}` - one record with key:value pairs
+     *
+     * @param {Object|Array<Object>} values
+     */
+    set(set) {
+      if (is.not.object(set)) {
+        throw new TypeError('values is of invalid type');
+      }
+
+      this._set = set;
+
+      return this;
+    }
+  };
+
+module.exports = SetMixin;

src/mixins/values.mixin.js

@@ -4,7 +4,7 @@ const ValuesMixin = C =>
   class ValuesMixin extends C {
     constructor() {
       super(...arguments);
-      this._offset = null;
+      this._values = null;
     }
 
     get valuesSQL() {
@@ -27,7 +27,7 @@ const ValuesMixin = C =>
     values(values) {
       values = force.array(values);
 
-      if (!is.array(values, 'object')) {
+      if (is.not.array(values, 'object')) {
         throw new TypeError('values is of invalid type');
       }
 

src/mixins/where.mixin.js

@@ -22,12 +22,12 @@ const WhereMixin = C =>
      * @param {Array<Object>} where
      */
     where(where) {
-      if (!is(where, ['string', 'object']))
+      if (is.not(where, ['string', 'object']))
         throw new TypeError('where is of invalid type');
 
       if (is.object(where)) {
         this._where = Object.entries(where)
-          .map(([key, value]) => `${key} = '${value}'`)
+          .map(([key, value]) => `${key}='${value}'`)
           .join(' AND ');
       } else {
         this._where = where;

tests/test.js

@@ -11,13 +11,7 @@ const db = new DB({
 
 const select = async () => {
   console.log('SELECT');
-  const select = db
-    .select('lorem')
-    .columns('*')
-    .orderBy({ id: 'DESC' })
-    .where(`"id" != '2'`)
-    .limit(1)
-    .offset(1);
+  const select = db.select('lorem').columns('*');
 
   console.log(select.query);
   if (await select.execute()) {
@@ -51,13 +45,24 @@ const del = async () => {
   }
 };
 
-(async () => {
-  await select();
-  // await insert();
-  // await select();
+const update = async () => {
+  console.log('UPDATE');
+  const update = db
+    .update('lorem')
+    .set({ foo: 'Updated Čau', bar: 420 })
+    .where({ id: 4 });
 
-  await del();
+  console.log(update.query);
+  if (await update.execute()) {
+    console.log(update.rows);
+  } else {
+    console.log(update.err);
+  }
+};
 
+(async () => {
+  await select();
+  await update();
   await select();
 
   process.exit();