feat: support multiple rows update

README.md

@@ -154,6 +154,45 @@ console.log(result);
   changedRows: 1 }
 ```
 
+- Update multiple rows with each row has a primary key: `id`
+
+```js
+let rows = [{
+  id: 123,
+  name: 'fengmk2',
+  fieldA: 'fieldA value',
+}, {
+  id: 456,
+  name: 'luckydrq',
+  fieldB: 'fieldB value'
+}];
+let result = yield db.updateRows('table-name', rows);
+
+=> UPDATE `table-name`
+     SET name = CASE id
+       WHEN 123 THEN 'fengmk2'
+       WHEN 456 THEN 'luckydrq'
+     END,
+     fieldA = CASE id
+       WHEN 123 THEN 'filedA value'
+     END,
+     fieldB = CASE id
+       WHEN 456 THEN 'fieldB value'
+     END
+   WHERE id IN(123, 456)
+
+console.log(result);
+{
+  fieldCount: 0,
+  affectedRows: 2,
+  insertId: 0,
+  serverStatus: 2,
+  warningCount: 0,
+  message: '',
+  protocol41: true,
+  changedRows: 2 }
+```
+
 ### Get
 
 - Get a row

lib/operator.js

@@ -14,7 +14,10 @@
  * Module dependencies.
  */
 
+const util = require('util');
 const debug = require('debug')('ali-rds:operator');
+const toArray = require('json-to-array');
+const merge = require('array-merges');
 const SqlString = require('./sqlstring');
 const literals = require('./literals');
 
@@ -63,7 +66,7 @@ proto.count = function* (table, where) {
   let sql = this.format('SELECT COUNT(*) as count FROM ??', [table]) +
     this._where(where);
   debug('count(%j, %j) \n=> %j', table, where, sql);
-  var rows = yield this.query(sql);
+  let rows = yield this.query(sql);
   return rows[0].count;
 };
 
@@ -116,8 +119,8 @@ proto.insert = function* (table, rows, options) {
   let params = [table, options.columns];
   let strs = [];
   for (let i = 0; i < rows.length; i++) {
-    var values = [];
-    var row = rows[i];
+    let values = [];
+    let row = rows[i];
     for (let j = 0; j < options.columns.length; j++) {
       values.push(row[options.columns[j]]);
     }
@@ -148,7 +151,7 @@ proto.update = function* (table, row, options) {
   let sets = [];
   let values = [];
   for (let i = 0; i < options.columns.length; i++) {
-    var column = options.columns[i];
+    let column = options.columns[i];
     if (column in options.where) {
       continue;
     }
@@ -163,6 +166,96 @@ proto.update = function* (table, row, options) {
   return yield this.query(sql);
 };
 
+/**
+ * Update multiple rows from a table
+ * @see http://stackoverflow.com/questions/2528181/update-multiple-rows-with-one-query
+ *
+ * @param  {String} table     table name
+ * @param  {Array} rows       row obj with a primary key `id`
+ * @return {Object} result
+ */
+proto.updateRows = function* (table, rows) {
+  if (!Array.isArray(rows)) {
+    rows = [rows];
+  }
+
+  let escape = this.escape;
+  let escapeId = this.escapeId;
+  let ids = [];
+  let rowArr = rows
+    .map(function(row) {
+      // {a: b, c: d} => [[a, b], [c, d]]
+      if (!row.hasOwnProperty('id')) {
+        throw new Error('Can\' update rows. Make sure each row has a id');
+      }
+
+      // escape first
+      row.id = escape(row.id);
+      ids.push(row.id);
+      return toArray(row, { excepts: ['id'] });
+    })
+    .reduce(function(prev, curr) {
+      // merge([[a, b]], [[a, c]]) => [[a, [b, c]]]
+      prev = merge(prev, curr, {
+        equal: equal,
+        onMerge: onMerge
+      });
+      return prev;
+    }, []);
+
+  function equal(prev, next) {
+    return prev[0] === next[0];
+  }
+
+  function onMerge(prev, next) {
+    if (Array.isArray(prev[1])) {
+      prev[1].push(next[1]);
+    } else {
+      prev[1] = [prev[1], next[1]];
+    }
+    return [[prev[0], prev[1]]];
+  }
+
+  // id 查找规则。多条记录可能拥有相同的key, value。
+  // 通过{id}_{key}做key，是唯一的。
+  let idMap = {};
+  function getId(key, value) {
+    for (let i = 0; i < rows.length; i++) {
+      if (rows[i][key] === value) {
+        let hashKey = rows[i].id + '_' + key;
+        if (idMap[hashKey]) {
+          continue;
+        } else {
+          idMap[hashKey] = true;
+          return rows[i].id;
+        }
+      }
+    }
+    return null;
+  }
+
+  let clauseTemplate = 'UPDATE %s SET %s WHERE id IN (%s)';
+  let subClauseTemplate = '%s = CASE id %s END';
+  let loopClauseTemplate = 'WHEN %s THEN %s';
+  let clauseArr = [];
+  table = escapeId(table);
+  rowArr.forEach(function(tuple) {
+    let key = tuple[0], values = Array.isArray(tuple[1]) ? tuple[1] : [tuple[1]];
+    let loopArr = [];
+    values.forEach(function(value) {
+      let id = getId(key, value);
+      if (id) {
+        value = escape(value);
+        loopArr.push(util.format(loopClauseTemplate, id, value));
+      }
+    });
+    clauseArr.push(util.format(subClauseTemplate, escapeId(key), loopArr.join(' ')));
+  });
+  let sql = util.format(clauseTemplate, table, clauseArr.join(','), ids.join(','));
+  debug('update(%j, %j, %j) \n=> %j', table, JSON.stringify(rows), sql);
+  return yield this.query(sql);
+};
+
 proto.delete = function* (table, where) {
   let sql = this.format('DELETE FROM ??', [table]) +
     this._where(where);

package.json

@@ -15,7 +15,9 @@
     "cnpm": "npm install --registry=https://registry.npm.taobao.org"
   },
   "dependencies": {
+    "array-merges": "^0.1.0",
     "debug": "~2.2.0",
+    "json-to-array": "^0.1.0",
     "mysql": "~2.7.0"
   },
   "devDependencies": {

test/operator.test.js

@@ -15,9 +15,18 @@
  */
 
 const assert = require('assert');
+const rds = require('..');
+const config = require('./config');
 const Operator = require('../lib/operator');
 
 describe('operator.test.js', function () {
+  const prefix = 'prefix-' + process.version + '-';
+  const table = 'user';
+  before(function* () {
+    this.db = rds(config);
+    yield this.db.query('delete from ?? where name like ?', [table, prefix + '%']);
+  });
+
   describe('_where(where)', function () {
     it('should get where sql', function () {
       let op = new Operator();
@@ -52,4 +61,33 @@ describe('operator.test.js', function () {
       }
     });
   });
+
+  describe('updateRows()', function() {
+    before(function* () {
+      yield this.db.query('insert into ??(name, email, gmt_create, gmt_modified) \
+        values(?, ?, now(), now())',
+        [table, prefix + 'luckydrq', prefix + '[email protected]']);
+      yield this.db.query('insert into ??(name, email, gmt_create, gmt_modified) \
+        values(?, ?, now(), now())',
+        [table, prefix + 'luckydrq2', prefix + '[email protected]']);
+    });
+
+    it('should update multiple rows', function* () {
+      let rows = yield this.db.query('select * from ?? where email=? order by id',
+        [table, prefix + '[email protected]']);
+      console.log(rows);
+      assert.equal(rows.length, 2);
+      assert.equal(rows[0].name, prefix + 'luckydrq');
+      assert.equal(rows[1].name, prefix + 'luckydrq2');
+
+      rows[0].name = prefix + 'drq';
+      rows[1].email = prefix + '[email protected]';
+      yield this.db.updateRows(table, rows);
+      let updatedRows = yield this.db.query('select * from ?? where id in (?, ?)',
+        [table, rows[0].id, rows[1].id]);
+        console.log(updatedRows);
+      assert.equal(updatedRows[0].name, prefix + 'drq');
+      assert.equal(updatedRows[1].email, prefix + '[email protected]');
+    });
+  });
 });