在Codeigniter中对WHERE子句进行分组

Question

我想在Codeigniter中使用Active Records生成以下SQL代码:

WHERE name != 'Joe' AND (age < 69 OR id > 50)

做到以下似乎是我能得到的,我无法弄清楚如何将它们分组

$this->db->select()->from('users')->where('name !=', 'Joe')->where('age <', 69)->or_where('id <', $id); 

有任何想法吗？我的SQL查询太复杂了,所以我不想重写传统SQL中的所有内容.

UPDATE

我的SQL代码是动态生成的,具体取决于传递给模型方法的某些参数的值.不能使用括号的问题会导致问题,因为运算符优先级是AND先评估的OR.

*这是我的活动记录代码的一大块,其中有一些其他代码在它之前和之后:

            ... some $this->db->where() ...
            ... some $this->db->where() ...

    if($price_range) {
        $price_array = explode('.', $price_range);
        for($i = 0; $i < count($price_array); $i++) {
            if($i == 0) {
                $this->db->where('places.price_range', $price_array[$i]);
            } else {
                $this->db->or_where('places.price_range', $price_array[$i]);
            }
        }

    }

            ... some $this->db->where() ...
            ... some $this->db->where() ...

问题来了,因为我正在使用$this->db->or_where()它引入了一个OR子句,它将运算符优先级抛到混乱状态而不能( )用来改变顺序.

**有什么方法可以解决这个问题吗？**

Answer 1

在Codeigniter 3.0.3中你可以这么简单:

$this->db->select()
  ->from('users')
  ->where('name !=', 'Joe')
  ->group_start() // Open bracket
  ->where('age <', 69)
  ->or_where('id <', $id)
  ->group_end(); // Close bracket

也许它可以帮助

Answer 2

您可以使用一个大字符串.

$this->db->select()->from('users')->where("name != 'Joe' AND (age < 69 OR id > 50) ");

Answer 3

默认情况下,where子句的分组不在CI中.你必须扩展核心并增加能力.我通过以下方式做了这样的事情:

class MY_DB_mysql_driver extends CI_DB_mysql_driver 
{       
    public function __construct($params) 
    {
    parent::__construct($params);
    }
    /** 
     * This function will allow you to do complex group where clauses in to c and (a AND b) or ( d and e)
     * This function is needed as else the where clause will append an automatic AND in front of each where Thus if you wanted to do something
     * like a AND ((b AND c) OR (d AND e)) you won't be able to as the where would insert it as a AND (AND (b...)) which is incorrect. 
     * Usage: start_group_where(key,value)->where(key,value)->close_group_where() or complex queries like
     *        open_bracket()->start_group_where(key,value)->where(key,value)->close_group_where()
     *        ->start_group_where(key,value,'','OR')->close_group_where()->close_bracket() would produce AND ((a AND b) OR (d))
     * @param $key mixed the table columns prefix.columnname
     * @param $value mixed the value of the key
     * @param $escape string any escape as per CI
     * @param $type the TYPE of query. By default it is set to 'AND' 
     * @return db object.  
     */
    function start_group_where($key,$value=NULL,$escape,$type="AND")
    {
        $this->open_bracket($type); 
        return parent::_where($key, $value,'',$escape); 
    }

    /**
     * Strictly used to have a consistent close function as the start_group_where. This essentially callse the close_bracket() function. 
     */
    function close_group_where()
    {
        return $this->close_bracket();  
    }

    /**
     * Allows to place a simple ( in a query and prepend it with the $type if needed. 
     * @param $type string add a ( to a query and prepend it with type. Default is $type. 
     * @param $return db object. 
     */
    function open_bracket($type="AND")
    {
        $this->ar_where[] = $type . " (";
        return $this;  
    }   

    /**
     * Allows to place a simple ) to a query. 
     */
    function close_bracket()
    {
        $this->ar_where[] = ")"; 
        return $this;       
    }
}

用法:

group_where_start(key,value)->where(key,value)->group_where_close() 

要么

像复杂的查询

open_bracket()->start_group_where(key,value)->where(key,value)->close_group_where()->start_group_where(key,value,'','OR')->close_group_where()->close_bracket() would produce AND ((a AND b) OR (d))

Answer 4

我所做的是在where之后复制and子句,这实际上与长字符串选择相同.

$this->db->select()
  ->from('users')
  ->where('name !=', 'Joe')
  ->where('age <', 69)
  ->or_where('id <', $id)
  ->where('name !=', 'Joe');

一个大的字符串方式可能更好.

Answer 5

CI3拥有您所需要的一切!

$this->db->select('*')->from('my_table')
        ->group_start()
                ->where('a', 'a')
                ->or_group_start()
                        ->where('b', 'b')
                        ->where('c', 'c')
                ->group_end()
        ->group_end()
        ->where('d', 'd')
->get();

https://www.codeigniter.com/userguide3/database/query_builder.html#query-grouping

Answer 6

解决了。动态生成 SQL 查询并将其插入到$this->db->where(). 多谢你们！