feat: update multiple rows (#55)

Author: nodejh

README.md

@@ -158,6 +158,74 @@ console.log(result);
   changedRows: 1 }
 ```
 
+### Update multiple rows
+
+-  Update multiple rows with primary key: `id`
+
+```js
+let options = [{
+  id: 123,
+  name: 'fengmk2',
+  email: 'm@fengmk2.com',
+  otherField: 'other field value',
+  modifiedAt: db.literals.now, // `now()` on db server
+}, {
+   id: 124,
+  name: 'fengmk2_2',
+  email: 'm@fengmk2_2.com',
+  otherField: 'other field value 2',
+  modifiedAt: db.literals.now, // `now()` on db server
+}]
+let result = yield db.updateRows('table-name', options);
+console.log(result);
+{ fieldCount: 0,
+  affectedRows: 2,
+  insertId: 0,
+  serverStatus: 2,
+  warningCount: 0,
+  message: '(Rows matched: 2  Changed: 2  Warnings: 0',
+  protocol41: true,
+  changedRows: 2 }
+```
+
+-  Update multiple rows with `row` and `where` properties
+
+
+```js
+let options = [{
+  row: {
+    email: 'm@fengmk2.com',
+    otherField: 'other field value',
+    modifiedAt: db.literals.now, // `now()` on db server
+  },
+  where: {
+    id: 123,
+    name: 'fengmk2',
+  }
+}, {
+  row: {
+    email: 'm@fengmk2_2.com',
+    otherField: 'other field value2',
+    modifiedAt: db.literals.now, // `now()` on db server
+  }, 
+  where: {
+    id: 124,
+    name: 'fengmk2_2',
+  }
+}]
+let result = yield db.updateRows('table-name', options);
+console.log(result);
+{ fieldCount: 0,
+  affectedRows: 2,
+  insertId: 0,
+  serverStatus: 2,
+  warningCount: 0,
+  message: '(Rows matched: 2  Changed: 2  Warnings: 0',
+  protocol41: true,
+  changedRows: 2 }
+```
+
+
 ### Get
 
 - Get a row
@@ -317,6 +385,7 @@ TBD
 - *get(table, where, options)
 - *insert(table, row[s], options)
 - *update(table, row, options)
+- *updateRows(table, options)
 - *delete(table, where)
 - *count(table, where)
 

lib/operator.js

@@ -142,7 +142,6 @@ proto.insert = function* (table, rows, options) {
 };
 
 proto.update = function* (table, row, options) {
-  // TODO: support multi rows
   options = options || {};
   if (!options.columns) {
     options.columns = Object.keys(row);
@@ -174,6 +173,134 @@ proto.update = function* (table, row, options) {
   return yield this.query(sql);
 };
 
+/**
+ *
+ * Update multiple rows from a table
+ *
+ * UPDATE `table_name` SET
+ *  `column1` CASE
+ *     WHEN  condition1 THEN 'value11'
+ *     WHEN  condition2 THEN 'value12'
+ *     WHEN  condition3 THEN 'value13'
+ *     ELSE `column1` END,
+ *  `column2` CASE
+ *     WHEN  condition1 THEN 'value21'
+ *     WHEN  condition2 THEN 'value22'
+ *     WHEN  condition3 THEN 'value23'
+ *     ELSE `column2` END
+ * WHERE condition
+ *
+ * See MySQL Case Syntax: https://dev.mysql.com/doc/refman/5.7/en/case.html
+ *
+ * @param {String} table table name
+ * @param {Array<Object>} options Object Arrays
+ *    each Object needs a primary key `id`, or each Object has `row` and `where` properties
+ *    e.g.
+ *      [{ id: 1, name: 'fengmk21' }]
+ *      or [{ row: { name: 'fengmk21' }, where: { id: 1 } }]
+ * @return {object} update result
+ */
+proto.updateRows = function* (table, options) {
+  if (!Array.isArray(options)) {
+    throw new Error('Options should be array');
+  }
+
+  /**
+   * {
+   *  column: {
+   *    when: [ 'WHEN condition1 THEN ?', 'WHEN condition12 THEN ?' ],
+   *    then: [ value1, value1 ]
+   *  }
+   * }
+   */
+  const SQL_CASE = {};
+  // e.g. { id: [], column: [] }
+  const WHERE = {};
+
+  options.forEach(option => {
+
+    if (!option.hasOwnProperty('id') && !(option.row && option.where)) {
+      throw new Error('Can not auto detect updateRows condition, please set option.row and option.where, or make sure option.id exists');
+    }
+
+    // convert { id, column } to { row: { column }, where: { id } }
+    if (option.hasOwnProperty('id')) {
+      const where = { id: option.id };
+      const row = Object.keys(option).reduce((result, key) => {
+        if (key !== 'id') {
+          result[key] = option[key];
+        }
+        return result;
+      }, {});
+      option = { row, where };
+    }
+
+    let where = this._where(option.where);
+    where = where.indexOf('WHERE') === -1 ? where : where.substring(where.indexOf('WHERE') + 5);
+    for (const key in option.row) {
+      if (!SQL_CASE[key]) {
+        SQL_CASE[key] = { when: [], then: [] };
+      }
+      SQL_CASE[key].when.push(' WHEN ' + where + ' THEN ? ');
+      SQL_CASE[key].then.push(option.row[key]);
+    }
+
+    for (const key in option.where) {
+      if (!WHERE[key]) {
+        WHERE[key] = [];
+      }
+      if (WHERE[key].indexOf(option.where[key]) === -1) {
+        WHERE[key].push(option.where[key]);
+      }
+    }
+  });
+
+  let SQL = [ 'UPDATE ?? SET ' ];
+  let VALUES = [ table ];
+
+  const TEMPLATE = [];
+  for (const key in SQL_CASE) {
+    let templateSql = ' ?? = CASE ';
+    VALUES.push(key);
+    templateSql += SQL_CASE[key].when.join(' ');
+    VALUES = VALUES.concat(SQL_CASE[key].then);
+    templateSql += ' ELSE ?? END ';
+    TEMPLATE.push(templateSql);
+    VALUES.push(key);
+  }
+
+  SQL += TEMPLATE.join(' , ');
+  SQL += this._where(WHERE);
+
+  /**
+   * e.g.
+   *
+   * updateRows(table, [
+   *  {id: 1, name: 'fengmk21', email: 'm@fengmk21.com'},
+   *  {id: 2, name: 'fengmk22', email: 'm@fengmk22.com'},
+   *  {id: 3, name: 'fengmk23', email: 'm@fengmk23.com'},
+   * ])
+   *
+   * UPDATE `ali-sdk-test-user` SET
+   *  `name` =
+   *    CASE
+   *      WHEN  `id` = 1 THEN 'fengmk21'
+   *      WHEN  `id` = 2 THEN 'fengmk22'
+   *      WHEN  `id` = 3 THEN 'fengmk23'
+   *      ELSE `name` END,
+   *  `email` =
+   *    CASE
+   *      WHEN  `id` = 1 THEN 'm@fengmk21.com'
+   *      WHEN  `id` = 2 THEN 'm@fengmk22.com'
+   *      WHEN  `id` = 3 THEN 'm@fengmk23.com'
+   *      ELSE `email` END
+   *  WHERE `id` IN (1, 2, 3)
+   */
+  const sql = this.format(SQL, VALUES);
+  debug('updateRows(%j, %j) \n=> %j', table, options, sql);
+  return yield this.query(sql);
+};
+
 proto.delete = function* (table, where) {
   const sql = this.format('DELETE FROM ??', [ table ]) +
     this._where(where);