在mysql中字段列表中的字段“ field”是不明确的

Question

INSERT INTO  users (phone, no_of_coupon) 
SELECT couponentries.phone, 1
FROM couponentries LEFT JOIN users ON couponentries.phone = 
users.phone
WHERE users.phone IS NULL
ON DUPLICATE KEY UPDATE users.no_of_coupon = users.no_of_coupon + 1;

I am trying to input date in the couponentries table and then it will automatically insert only the phone numbers into users table. If there is a duplicate phone number, no_of_coupon will increment by 1. But when I executed this code in the phpmyadmin trigger trigger , it has an error below. Could someone help me please? Thanks

Could not able to execute Column 'users.no_of_coupon' in field list is ambiguous

Answer 1

You need to provide an alias to users table used in join clause

INSERT INTO  users (phone, no_of_coupon) 
SELECT c.phone, 1
FROM couponentries c 
LEFT JOIN users u ON c.phone = u.phone
WHERE u.phone IS NULL
ON DUPLICATE KEY UPDATE users.no_of_coupon = users.no_of_coupon + 1;

I guess you don't need the join part you can just use

INSERT INTO users (phone) 
SELECT c.phone
FROM couponentries c 
ON DUPLICATE KEY UPDATE no_of_coupon = no_of_coupon + 1;

Demo