与 SQL 客户端中的运行相同查询相比，PHP 查询返回的结果正好少 1 个

Question

我有一个查询要获取一些数据。当我运行在TablePlus（数据库客户端）的SQL编辑器中查询时，结果符合预期。

当我将查询转换为我的 PHP 项目时，结果每次都偏离 1 条记录。下图是通过在 PHP 中执行查询对结果 return 进行 var_dump 的结果。注意数组值的数量和第一个结果。

可以看到 SQL 将 return 9 个结果，最上面的结果有 id 57115（正确）。 PHP 将 return 8 个结果与 id 57115 的记录丢失（不正确）。我的 PHP 项目使用 CodeIgniter 3.1.10 版。我试过使用 CodeIgniter 的查询生成器、常规 $this->db->query() 函数和 PHP 的 mysqli 扩展。所有这三种方法都给出相同的 8 行结果。也不只是 8 和 9 个结果，如果我修改查询，它总是会差一个。例如，我使用

行限制了按日期 return 编辑的结果

and `acd_3cx_leads`.`lastModified` >= '2022-01-01'

删除它会 return 2,449 个结果 SQL 而 PHP 会 return 2,448 个结果。再次落后 1。我完全不知道是什么原因造成的，它在所有 4 种实现中都是完全相同的查询，那么为什么 PHP 差了一个？

作为参考，这里有 4 个查询：

SQL

    select
      `acd_3cx_leads`.`id`,
      `acd_3cx_leads`.`dialCount`,
      @hoursSinceLastUpdate := timestampdiff(hour, `acd_3cx_leadstatus`.`createdOn`, NOW()) hoursSinceLastUpdate,
    max(acd_3cx_leadstatus.createdOn) leadCountLastUpdated,
    max(acd_3cx_lead_schedule_call_back_sms_log.smsType) lastSmsType
    from
      `acd_3cx_leads`
      left join `acd_3cx_leadstatus` on `acd_3cx_leadstatus`.`leadId` = `acd_3cx_leads`.`id`
        and `acd_3cx_leadstatus`.`dialCount` = `acd_3cx_leads`.`dialCount`
      left join `acd_3cx_lead_schedule_call_back_sms_log` on `acd_3cx_lead_schedule_call_back_sms_log`.`leadId` = `acd_3cx_leads`.`id`
    where
      `acd_3cx_leads`.`doNotContact` = 0
      and `acd_3cx_leads`.`active` = 1
      and `acd_3cx_leads`.`closeTypeId` is null
      and `acd_3cx_leads`.`lastModified` >= '2022-01-01'
    group by
      `acd_3cx_leads`.`id`
    having (acd_3cx_leads.dialCount = 1
      and @hoursSinceLastUpdate >= 5
      and lastSmsType is null)
      OR(acd_3cx_leads.dialCount = 1
        and @hoursSinceLastUpdate >= 24
        and(lastSmsType is null
          or lastSmsType < 2))
      OR(acd_3cx_leads.dialCount = 1
        and @hoursSinceLastUpdate >= 48
        and(lastSmsType is null
          or lastSmsType < 3))
      OR(acd_3cx_leads.dialCount = 2
        and @hoursSinceLastUpdate >= 4
        and lastSmsType is null)
      OR(acd_3cx_leads.dialCount = 2
        and @hoursSinceLastUpdate >= 24
        and(lastSmsType is null
          or lastSmsType < 2))
      OR(acd_3cx_leads.dialCount = 2
        and @hoursSinceLastUpdate >= 48
        and(lastSmsType is null
          or lastSmsType < 3))
      OR(acd_3cx_leads.dialCount = 3
        and @hoursSinceLastUpdate >= 6
        and(lastSmsType is null
          or lastSmsType < 4))
    order by
      `acd_3cx_leads`.`lastModified` desc

CodeIgniter 的查询生成器

    public function getRedialLeads(): array
    {
        $lead       = TABLE_NAMES['acd_3cx_leads'];
        $leadStatus = TABLE_NAMES['acd_3cx_leadstatus'];
        $smsLog     = TABLE_NAMES['acd_3cx_lead_schedule_call_back_sms_log'];

        $this->db->select("
            {$lead}.id,
            {$lead}.dialCount,
            @hoursSinceLastUpdate := timestampdiff(hour, {$leadStatus}.createdOn, NOW()) hoursSinceLastUpdate,
            max({$leadStatus}.createdOn) leadCountLastUpdated,
            max({$smsLog}.smsType) lastSmsType
        ");

        $this->db->join($leadStatus, "{$leadStatus}.leadId = {$lead}.id and {$leadStatus}.dialCount = {$lead}.dialCount", 'left');
        $this->db->join($smsLog, "{$smsLog}.leadId = {$lead}.id", 'left');

        $this->db->where("{$lead}.doNotContact", 0);
        $this->db->where("{$lead}.active", 1);
        $this->db->where("{$lead}.closeTypeId is null");
        $this->db->where("{$lead}.lastModified >= '2022-01-01'");

        $this->db->group_by("{$lead}.id");

        // Dial 2 after +5 hours
        $this->db->having("(
            {$lead}.dialCount = 1
            and @hoursSinceLastUpdate >= 5
            and lastSmsType is null
        )", null, false);

        // Dial 2 after +24 hours
        $this->db->or_having("(
            {$lead}.dialCount = 1
            and @hoursSinceLastUpdate >= 24
            and (lastSmsType is null or lastSmsType < 2)
        )", null, false);

        // Dial 2 after +48 hours
        $this->db->or_having("(
            {$lead}.dialCount = 1
            and @hoursSinceLastUpdate >= 48
            and (lastSmsType is null or lastSmsType < 3)
        )", null, false);

        // Dial 3 after +4 hours
        $this->db->or_having("(
            {$lead}.dialCount = 2
            and @hoursSinceLastUpdate >= 4
            and lastSmsType is null
        )", null, false);

        // Dial 3 after +24 hours
        $this->db->or_having("(
            {$lead}.dialCount = 2
            and @hoursSinceLastUpdate >= 24
            and (lastSmsType is null or lastSmsType < 2)
        )", null, false);

        // Dial 3 after +48 hours
        $this->db->or_having("(
            {$lead}.dialCount = 2
            and @hoursSinceLastUpdate >= 48
            and (lastSmsType is null or lastSmsType < 3)
        )", null, false);

        // Dial 4 after +6 hours
        $this->db->or_having("(
            {$lead}.dialCount = 3
            and @hoursSinceLastUpdate >= 6
            and (lastSmsType is null or lastSmsType < 4)
        )", null, false);

        $this->db->order_by("{$lead}.lastModified desc");

        return $this->db->get($lead)->result_array();
    }

CodeIgniter 的查询函数

    public function getRedialLeads2(): array
    {
        $query = $this->db->query("
            select
                `acd_3cx_leads`.`id`,
                `acd_3cx_leads`.`dialCount`,
                @hoursSinceLastUpdate := timestampdiff(hour, `acd_3cx_leadstatus`.`createdOn`, NOW()) hoursSinceLastUpdate,
                max(acd_3cx_leadstatus.createdOn) leadCountLastUpdated,
                max(acd_3cx_lead_schedule_call_back_sms_log.smsType) lastSmsType
            from
                `acd_3cx_leads`
                left join `acd_3cx_leadstatus` on `acd_3cx_leadstatus`.`leadId` = `acd_3cx_leads`.`id`
                and `acd_3cx_leadstatus`.`dialCount` = `acd_3cx_leads`.`dialCount`
                left join `acd_3cx_lead_schedule_call_back_sms_log` on `acd_3cx_lead_schedule_call_back_sms_log`.`leadId` = `acd_3cx_leads`.`id`
            where
                `acd_3cx_leads`.`doNotContact` = 0
                and `acd_3cx_leads`.`active` = 1
                and `acd_3cx_leads`.`closeTypeId` is null
                and `acd_3cx_leads`.`lastModified` >= '2022-01-01'
            group by
                `acd_3cx_leads`.`id`
            having (acd_3cx_leads.dialCount = 1
                and @hoursSinceLastUpdate >= 5
                and lastSmsType is null)
                OR(acd_3cx_leads.dialCount = 1
                    and @hoursSinceLastUpdate >= 24
                    and(lastSmsType is null
                        or lastSmsType < 2))
                OR(acd_3cx_leads.dialCount = 1
                    and @hoursSinceLastUpdate >= 48
                    and(lastSmsType is null
                        or lastSmsType < 3))
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 4
                    and lastSmsType is null)
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 24
                    and(lastSmsType is null
                        or lastSmsType < 2))
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 48
                    and(lastSmsType is null
                        or lastSmsType < 3))
                OR(acd_3cx_leads.dialCount = 3
                    and @hoursSinceLastUpdate >= 6
                    and(lastSmsType is null
                        or lastSmsType < 4))
            order by
                `acd_3cx_leads`.`lastModified` desc
        ");

        return $query->result_array();
    }

PHP 的 mysqli 扩展

    public function getRedialLeads3(): array
    {
        // Obviously omitted sensitive details
        $mysqli = mysqli_connect('hostname', 'username', 'password', 'database');
        $query  = "
            select
                `acd_3cx_leads`.`id`,
                `acd_3cx_leads`.`dialCount`,
                @hoursSinceLastUpdate := timestampdiff(hour, `acd_3cx_leadstatus`.`createdOn`, NOW()) hoursSinceLastUpdate,
                max(acd_3cx_leadstatus.createdOn) leadCountLastUpdated,
                max(acd_3cx_lead_schedule_call_back_sms_log.smsType) lastSmsType
            from
                `acd_3cx_leads`
                left join `acd_3cx_leadstatus` on `acd_3cx_leadstatus`.`leadId` = `acd_3cx_leads`.`id`
                and `acd_3cx_leadstatus`.`dialCount` = `acd_3cx_leads`.`dialCount`
                left join `acd_3cx_lead_schedule_call_back_sms_log` on `acd_3cx_lead_schedule_call_back_sms_log`.`leadId` = `acd_3cx_leads`.`id`
            where
                `acd_3cx_leads`.`doNotContact` = 0
                and `acd_3cx_leads`.`active` = 1
                and `acd_3cx_leads`.`closeTypeId` is null
                and `acd_3cx_leads`.`lastModified` >= '2022-01-01'
            group by
                `acd_3cx_leads`.`id`
            having (acd_3cx_leads.dialCount = 1
                and @hoursSinceLastUpdate >= 5
                and lastSmsType is null)
                OR(acd_3cx_leads.dialCount = 1
                    and @hoursSinceLastUpdate >= 24
                    and(lastSmsType is null
                        or lastSmsType < 2))
                OR(acd_3cx_leads.dialCount = 1
                    and @hoursSinceLastUpdate >= 48
                    and(lastSmsType is null
                        or lastSmsType < 3))
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 4
                    and lastSmsType is null)
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 24
                    and(lastSmsType is null
                        or lastSmsType < 2))
                OR(acd_3cx_leads.dialCount = 2
                    and @hoursSinceLastUpdate >= 48
                    and(lastSmsType is null
                        or lastSmsType < 3))
                OR(acd_3cx_leads.dialCount = 3
                    and @hoursSinceLastUpdate >= 6
                    and(lastSmsType is null
                        or lastSmsType < 4))
            order by
                `acd_3cx_leads`.`lastModified` desc
        ";
        $result = mysqli_query($mysqli, $query, MYSQLI_USE_RESULT);

        return mysqli_fetch_all($result, MYSQLI_ASSOC);
    }

Answer 1

根据@mickmackusa 的建议，我从 SELECT 和 HAVING 子句中删除了 SQL 变量 hoursSinceLastUpdate。这解决了我的问题。所以 SELECT 行

@hoursSinceLastUpdate := timestampdiff(hour, `acd_3cx_leadstatus`.`createdOn`, NOW()) hoursSinceLastUpdate,

现在

timestampdiff(hour, `acd_3cx_leadstatus`.`createdOn`, NOW()) hoursSinceLastUpdate,

在 HAVING 中，所有出现的

and @hoursSinceLastUpdate >= x

现在

and hoursSinceLastUpdate >= x

因此 SQL 和 PHP 的记录 return 之间现在存在奇偶校验。

与 SQL 客户端中的运行相同查询相比，PHP 查询返回的结果正好少 1 个

PHP query returning exactly 1 less result compared to running the same query in a SQL client

php

mysql

codeigniter

与 SQL 客户端中的 运行 相同查询相比，PHP 查询返回的结果正好少 1 个

PHP query returning exactly 1 less result compared to running the same query in a SQL client

php

mysql

codeigniter

与 SQL 客户端中的运行相同查询相比，PHP 查询返回的结果正好少 1 个