php - Codeigniter - 如何使用前一个查询的条件进行第二个 MySQL 查询

Question

嘿，我有以下问题:

我有一个很长的 MySQL 查询，然后我想计算它返回的行数。

得到这个结果后，我想在一定的限制下再次得到它，并按其中一列对我的结果进行分组。

所以看起来:

/* 
query conditions....
query conditions....
query conditions....
query conditions....
query conditions....
query conditions....
query conditions....
*/

//first query

$query = $this->db->get();

$results = $query->result_array(); 

$this->db->select("FOUND_ROWS() as cnt");

$cnt_array = $this->db->get()->row_array(); //here is my number of rows


//second query and if instruction


        if($sth==0) { $this->db->group_by(...);}


        $this->db->limit($count, $from);


        $query = $this->db->get();
        $results = $query->result_array();

        $this->db->select("FOUND_ROWS() as cnt");

        $tot_cnt = $this->db->get()->row_array(); //now i want to have number of grouped results. 

但是第二个查询不起作用，怎么办？

Answer 1

我对你的问题有点困惑。如果您只想运行完全相同的查询，但有时需要两个额外的命令 - 那么这就可以了。

如果您想使用第一个查询的结果运行第二个查询 - 那么这不会有帮助

function _generic_query()
{
    /* 
    query conditions....
    query conditions....
    query conditions....
    query conditions....
    query conditions....
    query conditions....
    query conditions....
    */
return;
}

function first_query()
{
    $this->_generic_query();

    $query = $this->db->get();
    $results = $query->result_array(); 
    $this->db->select("FOUND_ROWS() as cnt");
    $cnt_array = $this->db->get()->row_array(); //here is my number of rows
}

function second_query()
{
    $this->_generic_query();

    if($sth==0) { $this->db->group_by(...);}
    $this->db->limit($count, $from);
    $query = $this->db->get();
    $results = $query->result_array();
    $this->db->select("FOUND_ROWS() as cnt");
    $tot_cnt = $this->db->get()->row_array();
}