SQL查询返回的每个值都为NULL

Question

I have an SQL query that is simply returning a value of NULL in every field. It returns the correct number of rows for the amount of data inputted within the database but every column value shows as NULL rather than the value of the field in MySQL.

Can anyone offer any suggestions for me please?

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

I have tried the following now also and I still get NULL in place of every field value

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

Answer 1

Two things: You don't have to quote the field_id column name and you probably don't want to use LIKE on a numeric value.

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

Answer 2

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

Thanks to the advice everyone - this has resolved it for me perfectly.