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Author: onanying

README.md

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+## ShardingQuery
+
+根据时间分表的数据查询类
+
+## 使用方法
+
+ThinkPHP 5
+
+```php
+$shardingQuery = new ShardingQuery(
+    'think\Db::query',
+    [
+        'order',
+        'order_history',
+    ],
+    'SELECT * FROM {table}',
+    10,
+    0
+);
+$res           = $shardingQuery->select();
+var_dump($res);
+```

ShardingQuery.php

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+<?php
+
+/**
+ * 根据时间同构分表的查询类
+ * @author LIUJIAN <coder.keda@gmail.com>
+ */
+class ShardingQuery
+{
+
+    /**
+     * 数据库查询的回调
+     * 回调必须返回数组类型
+     * @var callable
+     */
+    public $callback;
+
+    /**
+     * 数据表列表
+     * 根据顺序查询
+     * @var array
+     */
+    public $tables;
+
+    /**
+     * 查询语句
+     * @var string
+     */
+    public $sql;
+
+    /**
+     * 限制数
+     * @var int
+     */
+    public $limit;
+
+    /**
+     * 偏移数
+     * @var int
+     */
+    public $offset;
+
+    /**
+     * 数据表的通配符
+     * @var string
+     */
+    protected static $tableSymbol = '{table}';
+
+    /**
+     * ShardingSelect constructor.
+     * @param array $tables
+     * @param callable $callback
+     * @param string $sql
+     */
+    public function __construct(callable $callback, array $tables, string $sql, int $limit, int $offset)
+    {
+        $this->callback = $callback;
+        $this->tables   = $tables;
+        $this->sql      = $sql;
+        $this->limit    = $limit;
+        $this->offset   = $offset;
+    }
+
+    /**
+     * 执行查询
+     * @return array
+     */
+    public function select()
+    {
+        $data = [];
+        foreach ($this->tables as $num => $table) {
+            if (count($data) < $this->limit) {
+                $limit  = $this->limit;
+                $offset = $this->offset;
+                if ($num > 0) {
+                    $limit  = $this->limit - count($data);
+                    $offset = 0;
+                }
+                $sql    = "{$this->sql} LIMIT {$limit} OFFSET {$offset}";
+                $sql    = str_replace(static::$tableSymbol, $table, $sql);
+                $result = call_user_func($this->callback, $sql);
+                if (empty($result)) {
+                    return $data;
+                }
+                $data = array_merge($data, $result);
+            }
+            if (count($data) >= $this->limit) {
+                return $data;
+            }
+        }
+        return $data;
+    }
+
+}