MySQL-如果不存在，返回0

现在我有一个非常大的查询，看起来像：

    $sql = "SELECT c.vin, c.case_id, c.claimnumber, c.platenumber, c.axrmrs_id, c.insurer_memberid, c.country, c.date_created, c.totalloss, c.lastcalc_manufacturer_code, c.lastcalc_model_code, c.lastcalc_submodel_code, c.audavin_triggered, c.accident_date, c.registration_date, c.manufacturing_year,
              cl.spareparts, cl.totalcosts, cl.laborhours, cl.laborcosts, cl.calculationdate, cl.paintlabor, cl.paintmaterial, cl.currency, car.manufacturer, car.model, car.submodel, org.name
              GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'L%',po.text,NULL) ORDER BY 1) AS textL,
              GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'E',po.text,NULL) ORDER BY 1) AS textE
            FROM axnmrs_cases AS c
              LEFT JOIN axnmrs_calculations as cl on c.case_id = cl.case_id AND c.country = cl.country
              LEFT JOIN axnmrs_positions as po on c.case_id = po.case_id
              LEFT JOIN car_type as car on car.manufacturer_code = c.lastcalc_manufacturer_code AND car.main_type = c.lastcalc_model_code AND car.subtype_code = c.lastcalc_submodel_code
              LEFT JOIN organization_list as org on org.memberId = c.insurer_memberid
            WHERE c.vin= :vin
              GROUP BY c.vin, c.case_id, c.axrmrs_id";

我有一个小问题，我的最后一个

左连接

查询并不总是返回

org.name

（这是短列表，所以不是所有ID都在那里）。 但是，如果

org.name

不存在，我想返回类似

0

的内容

有人能帮助我如何在不破坏

左连接

逻辑的情况下执行此操作吗？

非常感谢。
问候

---

Andurit

在选择中使用

IFNULL（org.name，0）

。

在选择中使用

IFNULL（org.name，0）

。

使用

合并功能：

SELECT c.vin, c.case_id, c.claimnumber, c.platenumber, c.axrmrs_id, c.insurer_memberid, c.country, c.date_created, c.totalloss, c.lastcalc_manufacturer_code, c.lastcalc_model_code, c.lastcalc_submodel_code, c.audavin_triggered, c.accident_date, c.registration_date, c.manufacturing_year,
                  cl.spareparts, cl.totalcosts, cl.laborhours, cl.laborcosts, cl.calculationdate, cl.paintlabor, cl.paintmaterial, cl.currency, car.manufacturer, car.model, car.submodel, 

                  COALESCE(org.name, 0) as name -- <--- Check this !!!

                  GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'L%',po.text,NULL) ORDER BY 1) AS textL,
                  GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'E',po.text,NULL) ORDER BY 1) AS textE
                FROM axnmrs_cases AS c
                  LEFT JOIN axnmrs_calculations as cl on c.case_id = cl.case_id AND c.country = cl.country
                  LEFT JOIN axnmrs_positions as po on c.case_id = po.case_id
                  LEFT JOIN car_type as car on car.manufacturer_code = c.lastcalc_manufacturer_code AND car.main_type = c.lastcalc_model_code AND car.subtype_code = c.lastcalc_submodel_code
                  LEFT JOIN organization_list as org on org.memberId = c.insurer_memberid
                WHERE c.vin= :vin
                  GROUP BY c.vin, c.case_id, c.axrmrs_id

选择c.vin、c.case\u id、c.claimnumber、c.platenumber、c.axrmrs\u id、c.Insurance\u memberid、c.country、c.date\u created、c.Totaloss、c.lastcalc\u Manufactor\u code、c.lastcalc\u model\u code、c.lastcalc\u submodel\u code、c.audavin\u triggered、c.Confect\u日期、c.Factory\u日期、c.manufacturing\u年份，
cl.备件、cl.总成本、cl.工时、cl.人工成本、cl.计算日期、cl.油漆人工、cl.油漆材料、cl.货币、汽车制造商、汽车模型、汽车子模型、，
合并（org.name，0）作为名称--使用
COALESCE
函数：

SELECT c.vin, c.case_id, c.claimnumber, c.platenumber, c.axrmrs_id, c.insurer_memberid, c.country, c.date_created, c.totalloss, c.lastcalc_manufacturer_code, c.lastcalc_model_code, c.lastcalc_submodel_code, c.audavin_triggered, c.accident_date, c.registration_date, c.manufacturing_year,
                  cl.spareparts, cl.totalcosts, cl.laborhours, cl.laborcosts, cl.calculationdate, cl.paintlabor, cl.paintmaterial, cl.currency, car.manufacturer, car.model, car.submodel, 

                  COALESCE(org.name, 0) as name -- <--- Check this !!!

                  GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'L%',po.text,NULL) ORDER BY 1) AS textL,
                  GROUP_CONCAT(DISTINCT IF(po.repairmethod LIKE 'E',po.text,NULL) ORDER BY 1) AS textE
                FROM axnmrs_cases AS c
                  LEFT JOIN axnmrs_calculations as cl on c.case_id = cl.case_id AND c.country = cl.country
                  LEFT JOIN axnmrs_positions as po on c.case_id = po.case_id
                  LEFT JOIN car_type as car on car.manufacturer_code = c.lastcalc_manufacturer_code AND car.main_type = c.lastcalc_model_code AND car.subtype_code = c.lastcalc_submodel_code
                  LEFT JOIN organization_list as org on org.memberId = c.insurer_memberid
                WHERE c.vin= :vin
                  GROUP BY c.vin, c.case_id, c.axrmrs_id

选择c.vin、c.case\u id、c.claimnumber、c.platenumber、c.axrmrs\u id、c.Insurance\u memberid、c.country、c.date\u created、c.Totaloss、c.lastcalc\u Manufactor\u code、c.lastcalc\u model\u code、c.lastcalc\u submodel\u code、c.audavin\u triggered、c.Confect\u日期、c.Factory\u日期、c.manufacturing\u年份，
cl.备件、cl.总成本、cl.工时、cl.人工成本、cl.计算日期、cl.油漆人工、cl.油漆材料、cl.货币、汽车制造商、汽车模型、汽车子模型、，
COALESCE（org.name，0）作为名称--hey@mikeb谢谢你的回答，它很完美，所以你必须竖起大拇指，但是Roberto是第一个保持公平的人，所以我认为他的答案是正确的。hey@mikeb感谢你的回答，它很完美，所以你必须竖起大拇指，但是Roberto是第一个保持公平的人，所以我认为他的答案是正确的。