改进多对多关联，支持中间表模型自定义 并且定义的时候不需要使用完整表名

library/think/model/Pivot.php

@@ -35,8 +35,9 @@ class Pivot extends Model
         }
 
         $this->parent = $parent;
-
+        if (is_null($this->name)) {
-        $this->table = $table;
+            $this->name = $table;
+        }
     }
 
 }

library/think/model/relation/BelongsToMany.php

@@ -24,8 +24,9 @@ class BelongsToMany extends Relation
 {
     // 中间表表名
     protected $middle;
-
+    // 中间表模型名称
-    // 中间表模型
+    protected $pivotName;
+    // 中间表模型对象
     protected $pivot;
 
     /**
@@ -43,8 +44,13 @@ class BelongsToMany extends Relation
         $this->model      = $model;
         $this->foreignKey = $foreignKey;
         $this->localKey   = $localKey;
-        $this->middle     = $table;
+        if (false === strpos($table, '\\')) {
-        $this->query      = (new $model)->db();
+            $this->middle = $table;
+        } else {
+            $this->pivotName = $table;
+        }
+        $this->query = (new $model)->db();
+        $this->pivot = $this->newPivot();
     }
 
     /**
@@ -54,7 +60,7 @@ class BelongsToMany extends Relation
      */
     public function pivot($pivot)
     {
-        $this->pivot = $pivot;
+        $this->pivotName = $pivot;
         return $this;
     }
 
@@ -63,9 +69,9 @@ class BelongsToMany extends Relation
      * @param $data
      * @return mixed
      */
-    protected function newPivot($data)
+    protected function newPivot($data = [])
     {
-        $pivot = $this->pivot ?: '\\think\\model\\Pivot';
+        $pivot = $this->pivotName ?: '\\think\\model\\Pivot';
         return new $pivot($this->parent, $data, $this->middle);
     }
 
@@ -102,7 +108,7 @@ class BelongsToMany extends Relation
         // 关联查询
         $pk                              = $this->parent->getPk();
         $condition['pivot.' . $localKey] = $this->parent->$pk;
-        return $this->belongsToManyQuery($middle, $foreignKey, $localKey, $condition);
+        return $this->belongsToManyQuery($foreignKey, $localKey, $condition);
     }
 
     /**
@@ -114,7 +120,7 @@ class BelongsToMany extends Relation
     public function getRelation($subRelation = '', $closure = null)
     {
         if ($closure) {
-            call_user_func_array($closure, [& $this->query]);
+            call_user_func_array($closure, [ & $this->query]);
         }
         $result = $this->buildQuery()->relation($subRelation)->select();
         $this->hydratePivot($result);
@@ -303,7 +309,7 @@ class BelongsToMany extends Relation
         $count = 0;
         if (isset($result->$pk)) {
             $pk    = $result->$pk;
-            $count = $this->belongsToManyQuery($this->middle, $this->foreignKey, $this->localKey, ['pivot.' . $this->localKey => $pk])->count();
+            $count = $this->belongsToManyQuery($this->foreignKey, $this->localKey, ['pivot.' . $this->localKey => $pk])->count();
         }
         return $count;
     }
@@ -316,7 +322,7 @@ class BelongsToMany extends Relation
      */
     public function getRelationCountQuery($closure)
     {
-        return $this->belongsToManyQuery($this->middle, $this->foreignKey, $this->localKey, [
+        return $this->belongsToManyQuery($this->foreignKey, $this->localKey, [
             'pivot.' . $this->localKey => [
                 'exp',
                 '=' . $this->parent->getTable() . '.' . $this->parent->getPk(),
@@ -335,7 +341,7 @@ class BelongsToMany extends Relation
     protected function eagerlyManyToMany($where, $relation, $subRelation = '')
     {
         // 预载入关联查询 支持嵌套预载入
-        $list = $this->belongsToManyQuery($this->middle, $this->foreignKey, $this->localKey, $where)->with($subRelation)->select();
+        $list = $this->belongsToManyQuery($this->foreignKey, $this->localKey, $where)->with($subRelation)->select();
 
         // 组装模型数据
         $data = [];
@@ -359,13 +365,12 @@ class BelongsToMany extends Relation
     /**
      * BELONGS TO MANY 关联查询
      * @access public
-     * @param string $table      中间表名
      * @param string $foreignKey 关联模型关联键
      * @param string $localKey   当前模型关联键
      * @param array  $condition  关联查询条件
      * @return Query
      */
-    protected function belongsToManyQuery($table, $foreignKey, $localKey, $condition = [])
+    protected function belongsToManyQuery($foreignKey, $localKey, $condition = [])
     {
         // 关联查询封装
         $tableName  = $this->query->getTable();
@@ -374,6 +379,7 @@ class BelongsToMany extends Relation
             ->field(true, false, $table, 'pivot', 'pivot__');
 
         if (empty($this->baseQuery)) {
+            $table = $this->pivot->getTable();
             $query->join($table . ' pivot', 'pivot.' . $foreignKey . '=' . $tableName . '.' . $relationFk)
                 ->where($condition);
         }
@@ -450,7 +456,7 @@ class BelongsToMany extends Relation
             $ids                    = (array) $id;
             foreach ($ids as $id) {
                 $pivot[$this->foreignKey] = $id;
-                $this->query->table($this->middle)->insert($pivot, true);
+                $this->pivot->insert($pivot, true);
                 $result[] = $this->newPivot($pivot);
             }
             if (count($result) == 1) {
@@ -488,8 +494,7 @@ class BelongsToMany extends Relation
         if (isset($id)) {
             $pivot[$this->foreignKey] = is_array($id) ? ['in', $id] : $id;
         }
-        $this->query->table($this->middle)->where($pivot)->delete();
+        $this->pivot->where($pivot)->delete();
-
         // 删除关联表数据
         if (isset($id) && $relationDel) {
             $model = $this->model;
@@ -505,8 +510,9 @@ class BelongsToMany extends Relation
     protected function baseQuery()
     {
         if (empty($this->baseQuery)) {
-            $pk = $this->parent->getPk();
+            $pk    = $this->parent->getPk();
-            $this->query->join($this->middle . ' pivot', 'pivot.' . $this->foreignKey . '=' . $this->query->getTable() . '.' . $this->query->getPk())->where('pivot.' . $this->localKey, $this->parent->$pk);
+            $table = $this->pivot->getTable();
+            $this->query->join($table . ' pivot', 'pivot.' . $this->foreignKey . '=' . $this->query->getTable() . '.' . $this->query->getPk())->where('pivot.' . $this->localKey, $this->parent->$pk);
             $this->baseQuery = true;
         }
     }