SQL查询返回每个值为NULL

我有一个SQL查询，它只是在每个字段中返回一个NULL值。它为数据库中输入的数据量返回正确的行数，但每个列值显示为NULL而不是MySQL中字段的值。SQL查询返回每个值为NULL

任何人都可以为我提供任何建议吗？

SELECT items.form_id as 'Form ID', 
MAX(IF('field_id' LIKE 88,meta_value,NULL)) AS 'User ID', 
MAX(IF('field_id' LIKE 96,meta_value,NULL)) AS 'Display Name', 
MAX(IF('field_id' LIKE 95,meta_value,NULL)) AS 'User Role', 
MAX(IF('field_id' LIKE 301,meta_value,NULL)) AS 'Your District', 
MAX(IF('field_id' LIKE 97,meta_value,NULL)) AS 'Time Duty Logged', 
MAX(IF('field_id' LIKE 84,meta_value,NULL)) AS 'Date of Duty', 
MAX(IF('field_id' LIKE 85,meta_value,NULL)) AS 'Duty Start Time', 
MAX(IF('field_id' LIKE 86,meta_value,NULL)) AS 'Duty End Time', 
MAX(IF('field_id' LIKE 139,meta_value,NULL)) AS 'Duty Status', 
MAX(IF('field_id' LIKE 142,meta_value,NULL)) AS 'Duty Type', 
MAX(IF('field_id' LIKE 174,meta_value,NULL)) AS 'Which Event?', 
MAX(IF('field_id' LIKE 103,meta_value,NULL)) AS 'Total Hours', 
MAX(IF('field_id' LIKE 135,meta_value,NULL)) AS 'Duty Details', 
MAX(IF('field_id' LIKE 136,meta_value,NULL)) AS 'End Section', 
MAX(IF('field_id' LIKE 227,meta_value,NULL)) AS 'User Details', 
MAX(IF('field_id' LIKE 228,meta_value,NULL)) AS 'End Section' 
FROM wp_frm_item_metas as meta 
JOIN wp_frm_items as items ON (items.id = meta.item_id) 
WHERE items.form_id LIKE 6 
GROUP BY meta.item_id

我已经试过了，现在也跟随我仍然得到NULL到位每个字段的值

SELECT items.form_id as 'Form ID', 
MAX(IF('field_id' = 88,meta_value,NULL)) AS 'User_ID', 
MAX(IF('field_id' = 96,meta_value,NULL)) AS 'Display_Name', 
MAX(IF('field_id' = 95,meta_value,NULL)) AS 'User_Role', 
MAX(IF('field_id' = 301,meta_value,NULL)) AS 'Your_District', 
MAX(IF('field_id' = 97,meta_value,NULL)) AS 'Time_Duty_Logged', 
MAX(IF('field_id' = 84,meta_value,NULL)) AS 'Date_of_Duty', 
MAX(IF('field_id' = 85,meta_value,NULL)) AS 'Duty_Start_Time', 
MAX(IF('field_id' = 86,meta_value,NULL)) AS 'Duty_End_Time', 
MAX(IF('field_id' = 139,meta_value,NULL)) AS 'Duty_Status', 
MAX(IF('field_id' = 142,meta_value,NULL)) AS 'Duty_Type', 
MAX(IF('field_id' = 174,meta_value,NULL)) AS 'Which_Event?', 
MAX(IF('field_id' = 103,meta_value,NULL)) AS 'Total_Hours', 
MAX(IF('field_id' = 135,meta_value,NULL)) AS 'Duty_Details', 
MAX(IF('field_id' = 136,meta_value,NULL)) AS 'End_Section', 
MAX(IF('field_id' = 227,meta_value,NULL)) AS 'User_Details', 
MAX(IF('field_id' = 228,meta_value,NULL)) AS 'End_Section' 
FROM wp_frm_item_metas as meta 
JOIN wp_frm_items as items ON (items.id = meta.item_id) 
WHERE items.form_id = 6 
GROUP BY meta.item_id

来源

2016-01-18 Wayne

使用'User_ID'而不是'User ID'等等（没有空格！） – Tewdyn

field_ID需要反标记而不是撇号以及别名。因为它将'Field_ID'的比较字符串值设置为'88'，这永远不会相等。 like运算符也需要％来比较动态值。如果field_ID是数字，我会建议直接向上=''比较 – xQbert

您使用单引号而不是反引号。我投票将这些类型的问题视为简单的印刷错误。 –

两件事情：您不必引用field_id列名，你可能不要对数字值不想使用LIKE。

SELECT items.form_id as 'Form ID', 
MAX(IF(field_id = 88,meta_value,NULL)) AS 'User_ID', 
MAX(IF(field_id = 96,meta_value,NULL)) AS 'Display_Name', 
MAX(IF(field_id = 95,meta_value,NULL)) AS 'User_Role', 
MAX(IF(field_id = 301,meta_value,NULL)) AS 'Your_District', 
MAX(IF(field_id = 97,meta_value,NULL)) AS 'Time_Duty_Logged', 
MAX(IF(field_id = 84,meta_value,NULL)) AS 'Date_of_Duty', 
MAX(IF(field_id = 85,meta_value,NULL)) AS 'Duty_Start_Time', 
MAX(IF(field_id = 86,meta_value,NULL)) AS 'Duty_End_Time', 
MAX(IF(field_id = 139,meta_value,NULL)) AS 'Duty_Status', 
MAX(IF(field_id = 142,meta_value,NULL)) AS 'Duty_Type', 
MAX(IF(field_id = 174,meta_value,NULL)) AS 'Which_Event?', 
MAX(IF(field_id = 103,meta_value,NULL)) AS 'Total_Hours', 
MAX(IF(field_id = 135,meta_value,NULL)) AS 'Duty_Details', 
MAX(IF(field_id = 136,meta_value,NULL)) AS 'End_Section', 
MAX(IF(field_id = 227,meta_value,NULL)) AS 'User_Details', 
MAX(IF(field_id = 228,meta_value,NULL)) AS 'End_Section' 
FROM wp_frm_item_metas as meta 
JOIN wp_frm_items as items ON (items.id = meta.item_id) 
WHERE items.form_id = 6 
GROUP BY meta.item_id

来源

2016-01-18 18:27:40

SELECT items.form_id as `Form ID`, 
MAX(IF(`field_id` = 88,meta_value,NULL)) AS `User ID`, 
MAX(IF(`field_id` = 96,meta_value,NULL)) AS `Display Name`, 
MAX(IF(`field_id` = 95,meta_value,NULL)) AS `User Role`, 
MAX(IF(`field_id` = 301,meta_value,NULL)) AS `Your District`, 
MAX(IF(`field_id` = 97,meta_value,NULL)) AS `Time Duty Logged`, 
MAX(IF(`field_id` = 84,meta_value,NULL)) AS `Date of Duty`, 
MAX(IF(`field_id` = 85,meta_value,NULL)) AS `Duty Start Time`, 
MAX(IF(`field_id` = 86,meta_value,NULL)) AS `Duty End Time`, 
MAX(IF(`field_id` = 139,meta_value,NULL)) AS `Duty Status`, 
MAX(IF(`field_id` = 142,meta_value,NULL)) AS `Duty Type`, 
MAX(IF(`field_id` = 174,meta_value,NULL)) AS `Which Event?`, 
MAX(IF(`field_id` = 103,meta_value,NULL)) AS `Total Hours`, 
MAX(IF(`field_id` = 135,meta_value,NULL)) AS `Duty Details`, 
MAX(IF(`field_id` = 136,meta_value,NULL)) AS `End Section`, 
MAX(IF(`field_id` = 227,meta_value,NULL)) AS `User Details`, 
MAX(IF(`field_id` = 228,meta_value,NULL)) AS `End Section` 
FROM wp_frm_item_metas as meta 
JOIN wp_frm_items as items ON (items.id = meta.item_id) 
WHERE items.form_id = 6 
GROUP BY meta.item_id

多亏了大家的意见 - 这已经完美解决了对我来说。

来源

2016-01-18 18:29:34 Wayne

SQL查询返回每个值为NULL

回答

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