feature addition: aggregate functions

README.md

@@ -41,6 +41,7 @@ That's it!
 * Fields
 * Group By
 * Group By, Order By
+* Aggregate functions :tada:
 * Relations
 * Run dynamic queries
 * Upload single file
@@ -170,6 +171,49 @@ eg: SELECT country,city,count(*) FROM offices GROUP BY country,city ORDER BY cit
 eg: SELECT country,city,count(*) FROM offices GROUP BY country,city ORDER BY city ASC, country DESC
 
 
+## Aggregate functions :jack_o_lantern: :sunglasses:
+
+```
+http://localhost:3000/api/payments/aggregate?_fields=amount
+
+[
+    {
+        "min_of_amount": 615.45,
+        "max_of_amount": 120166.58,
+        "avg_of_amount": 32431.645531,
+        "sum_of_amount": 8853839.23,
+        "stddev_of_amount": 20958.625377426568,
+        "variance_of_amount": 439263977.71130896
+    }
+]
+```
+
+eg: retrieves all numeric aggregate of a column in a table
+
+```
+http://localhost:3000/api/orderDetails/aggregate?_fields=priceEach,quantityOrdered
+[
+    {
+        "min_of_priceEach": 26.55,
+        "max_of_priceEach": 214.3,
+        "avg_of_priceEach": 90.769499,
+        "sum_of_priceEach": 271945.42,
+        "stddev_of_priceEach": 36.576811252187795,
+        "variance_of_priceEach": 1337.8631213781719,
+        "min_of_quantityOrdered": 6,
+        "max_of_quantityOrdered": 97,
+        "avg_of_quantityOrdered": 35.219,
+        "sum_of_quantityOrdered": 105516,
+        "stddev_of_quantityOrdered": 9.832243813502942,
+        "variance_of_quantityOrdered": 96.67301840816688
+    }
+]
+```
+
+eg: retrieves numeric aggregate can be done for multiple columns too 
+
+
+
 ## Relational Tables
 xmysql identifies foreign key relations automatically and provides GET api.
 ```

lib/util/cmd.helper.js

@@ -11,7 +11,7 @@ program.on('--help', () => {
 })
 
 program
-  .version('0.0.5')
+  .version('0.0.6')
   .option('-h, --host <n>', 'hostname')
   .option('-d, --database <n>', 'database schema name')
   .option('-u, --user <n>', 'username of database / root by default')
@@ -52,9 +52,6 @@ exports.handle = program => {
   program.host = program.host || 'localhost';
   program.storageFolder = program.storageFolder || process.cwd()
 
-  console.log('storage::', program.storageFolder);
-
-
   program.connectionLimit = 10;
 
   if (program.host === 'localhost' || program.host === '127.0.0.1' || program.host === '::1') {

lib/xapi.js

@@ -168,6 +168,12 @@ class Xapi {
               .get(this.asyncMiddleware(this.groupBy.bind(this)));
             break;
 
+          case 'aggregate':
+            this.app.route(routes[i]['routeUrl'])
+              .get(this.asyncMiddleware(this.aggregate.bind(this)));
+            break;
+
+
         }
       }
     }
@@ -189,8 +195,6 @@ class Xapi {
     }
 
 
-
-
   }
 
   async create(req, res) {
@@ -431,6 +435,41 @@ class Xapi {
 
   }
 
+  async aggregate(req, res) {
+
+    let tableName = req.app.locals._tableName;
+    let query = 'select '
+    let params = []
+    let fields = req.query._fields.split(',');
+
+    for (var i = 0; i < fields.length; ++i) {
+      if (i) {
+        query = query + ','
+      }
+      query = query + ' min(??) as ?,max(??) as ?,avg(??) as ?,sum(??) as ?,stddev(??) as ?,variance(??) as ? '
+      params.push(fields[i]);
+      params.push('min_of_' + fields[i]);
+      params.push(fields[i]);
+      params.push('max_of_' + fields[i]);
+      params.push(fields[i]);
+      params.push('avg_of_' + fields[i]);
+      params.push(fields[i]);
+      params.push('sum_of_' + fields[i]);
+      params.push(fields[i]);
+      params.push('stddev_of_' + fields[i]);
+      params.push(fields[i]);
+      params.push('variance_of_' + fields[i]);
+    }
+
+    query = query + ' from ??'
+    params.push(tableName)
+
+    var results = await this.mysql.exec(query, params);
+
+    res.status(200).json(results);
+
+  }
+
 
   /**************** START : files related ****************/
   downloadFile(req, res) {
@@ -463,6 +502,7 @@ class Xapi {
     }
 
   }
+
   /**************** END : files related ****************/
 
 }

lib/xsql.js

@@ -391,6 +391,7 @@ class Xsql {
       routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName + '/describe', 'describe'))
       routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName + '/count', 'count'))
       routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName + '/groupby', 'groupby'))
+      routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName + '/aggregate', 'aggregate'))
       routes.push(this.prepareRoute(internal, 'post', apiPrefix, tableName, 'create'))
       routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName, 'list'))
       routes.push(this.prepareRoute(internal, 'get', apiPrefix, tableName + '/:id', 'read'))

package.json

@@ -1,6 +1,6 @@
 {
   "name": "xmysql",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "description": "One command to generate REST APIs for any MySql database",
   "main": "index.js",
   "scripts": {

tests/tests.js

@@ -700,5 +700,27 @@ describe('xmysql : tests', function () {
       });
   });
 
+  it('GET /api/orders/aggregate?_fields=orderNumber,customerNumber should PASS', function (done) {
+
+    //post to an url with data
+    agent.get('/api/orders/aggregate?_fields=orderNumber,customerNumber')     //enter url
+      .expect(200)//200 for success 4xx for failure
+      .end(function (err, res) {
+        // Handle /api/v error
+        if (err) {
+          return done(err);
+        }
+
+        //validate response
+        res.body[0]['min_of_orderNumber'].should.be.equals(10100)
+        res.body[0]['max_of_orderNumber'].should.be.equals(10425)
+        res.body[0]['sum_of_orderNumber'].should.be.equals(3345575)
+        Object.keys(res.body[0]).length.should.be.equals(12)
+
+        return done();
+
+      });
+  });
+
 
 });