feat(belongsToMany): add countDistinct method (#224)

* feat(belongsToMany): add countDistinct method #221 * test(belongsToMany): test for countDistinct * refactor(belongsToMany): remove duplicate code in aggregate methods
adonisjs · Nov 7, 2017 · 26cca0e · 26cca0e
1 parent 2c6c56c
commit 26cca0e
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Showing 2 changed files with 54 additions and 12 deletions.
diff --git a/src/Lucid/Relations/BelongsToMany.js b/src/Lucid/Relations/BelongsToMany.js
@@ -658,6 +658,17 @@ class BelongsToMany extends BaseRelation {
     context.on(`${this.$primaryTable}.${this.primaryKey}`, '=', `${this.$pivotTable}.${this.foreignKey}`)
   }
 
+  /**
+   * Prepare query for an aggregate function
+   *
+   * @method _prepareAggregate
+   */
+  _prepareAggregate () {
+    this._validateRead()
+    this._makeJoinQuery()
+    this.wherePivot(this.foreignKey, this.$primaryKeyValue)
+  }
+
   /**
    * Returns count of rows.
    *
@@ -668,12 +679,24 @@ class BelongsToMany extends BaseRelation {
    * @return {Array}
    */
   count (expression) {
-    this._validateRead()
-    this._makeJoinQuery()
-    this.wherePivot(this.foreignKey, this.$primaryKeyValue)
+    this._prepareAggregate()
     return this.relatedQuery.count(expression)
   }
 
+  /**
+   * Returns count of rows with distinct expression.
+   *
+   * @method count
+   *
+   * @param  {String} expression
+   *
+   * @return {Array}
+   */
+  countDistinct (expression) {
+    this._prepareAggregate()
+    return this.relatedQuery.countDistinct(expression)
+  }
+
   /**
    * Returns avg for a given column
    *
@@ -684,9 +707,7 @@ class BelongsToMany extends BaseRelation {
    * @return {Array}
    */
   avg (column) {
-    this._validateRead()
-    this._makeJoinQuery()
-    this.wherePivot(this.foreignKey, this.$primaryKeyValue)
+    this._prepareAggregate()
     return this.relatedQuery.avg(column)
   }
 
@@ -700,9 +721,7 @@ class BelongsToMany extends BaseRelation {
    * @return {Array}
    */
   min (column) {
-    this._validateRead()
-    this._makeJoinQuery()
-    this.wherePivot(this.foreignKey, this.$primaryKeyValue)
+    this._prepareAggregate()
     return this.relatedQuery.min(column)
   }
 
@@ -716,9 +735,7 @@ class BelongsToMany extends BaseRelation {
    * @return {Array}
    */
   max (column) {
-    this._validateRead()
-    this._makeJoinQuery()
-    this.wherePivot(this.foreignKey, this.$primaryKeyValue)
+    this._prepareAggregate()
     return this.relatedQuery.max(column)
   }
 

diff --git a/test/unit/lucid-belongs-to-many.spec.js b/test/unit/lucid-belongs-to-many.spec.js
@@ -1738,4 +1738,29 @@ test.group('Relations | Belongs To Many', (group) => {
     const postsCount = await user.posts().count('* as total')
     assert.deepEqual(postsCount, [{ 'total': 2 }])
   })
+
+  test('count distinct on given field', async (assert) => {
+    class Post extends Model {
+    }
+
+    class User extends Model {
+      posts () {
+        return this.belongsToMany(Post)
+      }
+    }
+
+    User._bootIfNotBooted()
+    Post._bootIfNotBooted()
+
+    await ioc.use('Database').table('users').insert({ id: 20, username: 'virk' })
+    await ioc.use('Database').table('posts').insert([{ id: 18, title: 'Adonis 101' }, { id: 19, title: 'Lucid 101' }])
+    await ioc.use('Database').table('post_user').insert([
+      { post_id: 18, user_id: 20 },
+      { post_id: 19, user_id: 20 }
+    ])
+
+    const user = await User.find(20)
+    const postsCount = await user.posts().countDistinct('post_user.user_id as total')
+    assert.deepEqual(postsCount, [{ 'total': 1 }])
+  })
 })