Allow explicit data types

Override columnDataType function

Add test cases

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Use date type as explicit datatype

lib/migration.js

@@ -702,6 +702,33 @@ function mixinMigration(MySQL, mysql) {
     return line;
   };
 
+  // override this function from base connector to allow mysql connector to
+  // accept dataPrecision and dataScale as column specific properties
+  MySQL.prototype.columnDataType = function(model, property) {
+    var columnMetadata = this.columnMetadata(model, property);
+    var colType = columnMetadata && columnMetadata.dataType;
+    if (colType) {
+      colType = colType.toUpperCase();
+    }
+    var prop = this.getModelDefinition(model).properties[property];
+    if (!prop) {
+      return null;
+    }
+    var colLength = columnMetadata && columnMetadata.dataLength || prop.length || prop.limit;
+    var colPrecision = columnMetadata && columnMetadata.dataPrecision;
+    var colScale = columnMetadata && columnMetadata.dataScale;
+    // info on setting column specific properties
+    // i.e dataLength, dataPrecision, dataScale
+    // https://loopback.io/doc/en/lb3/Model-definition-JSON-file.html
+    if (colType) {
+      if (colLength) return colType + '(' + colLength + ')';
+      if (colPrecision && colScale) return colType + '(' + colPrecision + ',' + colScale + ')';
+      if (colPrecision) return colType + '(' + colPrecision + ')';
+      return colType;
+    }
+    return this.buildColumnType(prop);
+  };
+
   MySQL.prototype.buildColumnType = function buildColumnType(propertyDefinition) {
     var dt = '';
     var p = propertyDefinition;
@@ -743,7 +770,9 @@ function mixinMigration(MySQL, mysql) {
 
   function columnType(p, defaultType) {
     var dt = defaultType;
-    if (p.dataType) {
+    if (p.mysql && p.mysql.dataType) {
+      dt = String(p.mysql.dataType);
+    } else if (p.dataType) {
       dt = String(p.dataType);
     }
     return dt;

package.json

@@ -15,6 +15,7 @@
   "dependencies": {
     "async": "^0.9.0",
     "debug": "^2.1.1",
+    "lodash": "^4.17.4",
     "loopback-connector": "^4.0.0",
     "mysql": "^2.11.1",
     "strong-globalize": "^2.5.8"

test/datatypes.test.js

@@ -6,13 +6,106 @@
 'use strict';
 require('./init.js');
 var assert = require('assert');
+var _ = require('lodash');
 
-var db, BlobModel, EnumModel, ANIMAL_ENUM;
+var db, BlobModel, EnumModel, ANIMAL_ENUM, City, Account;
 var mysqlVersion;
 
 describe('MySQL specific datatypes', function() {
   before(setup);
 
+  describe('Support explicit datatypes on a property', function() {
+    var dateString1 = '2017-04-01';
+    var dateString2 = '2016-01-30';
+    var dateForTransactions = [new Date(dateString1).toString(), new Date(dateString2).toString()];
+    var data = [
+      {
+        type: 'Student - Basic',
+        amount: 1000,
+        lastTransaction: dateString1,
+      },
+      {
+        type: 'Professional',
+        amount: 1999.99,
+        lastTransaction: dateString2,
+      },
+    ];
+    before(function(done) {
+      require('./init.js');
+      db = getSchema();
+      Account = db.define('Account', {
+        type: {type: String},
+        amount: {
+          type: Number,
+          mysql: {
+            dataType: 'DECIMAL',
+            dataPrecision: 10,
+            dataScale: 2,
+          },
+        },
+        lastTransaction: {
+          type: String,
+          mysql: {
+            dataType: 'DATE',
+          },
+        },
+      });
+      db.automigrate(done);
+    });
+    after(function(done) {
+      Account.destroyAll(done);
+    });
+
+    it('create an instance', function(done) {
+      Account.create(data, function(err, result) {
+        assert(!err);
+        assert(result);
+        assert(_.isEqual(data.length, result.length));
+        assert(_.isEqual(data[0].amount, result[0].amount));
+        assert(_.isEqual(data[1].amount, result[1].amount));
+        done();
+      });
+    });
+
+    it('find an instance', function(done) {
+      Account.find(function(err, result) {
+        assert(!err);
+        assert(result);
+        assert(_.isEqual(data.length, result.length));
+        assert(_.isEqual(data[0].amount, result[0].amount));
+        assert(_.isEqual(data[1].amount, result[1].amount));
+        assert(_.isEqual(dateForTransactions[0], result[0].lastTransaction));
+        assert(_.isEqual(dateForTransactions[1], result[1].lastTransaction));
+        done();
+      });
+    });
+
+    it('find an instance by id', function(done) {
+      Account.findById(1, function(err, result) {
+        assert(!err);
+        assert(result);
+        assert(_.isEqual(data[0].amount, result.amount));
+        assert(_.isEqual(dateForTransactions[0], result.lastTransaction));
+        done();
+      });
+    });
+
+    it('update an instance', function(done) {
+      var updatedData = {
+        type: 'Student - Basic',
+        amount: 1155.77,
+        users: {},
+      };
+      Account.update({id: 1}, updatedData, function(err, result) {
+        assert(!err);
+        assert(result);
+        assert(result.count);
+        assert.equal(1, result.count);
+        done();
+      });
+    });
+  });
+
   it('should run migration', function(done) {
     db.automigrate(function() {
       done();