Geek asks and answers

Why did 2 left connections causing an error remain in one request?

Note . If you are looking for a solution to your problem, and you are attracted here, this probably will not help you. If you are not analyzing a single SQL query for an error, since in fact the error may exist in the next query, without your knowledge, this question may not help you. I am just warning you now because none of the data presented in this question actually leads to an answer.


To expand the database table regular_ruleswithout changing the table itself, I created an additional table ( extended_rules), whose PK is also FK before regular_rules. Then I can place any new columns in extended_rules, and then at any time when I load a record from it, I just need to join it with regular_rules, in order to treat it as if it were a complete object. Thus, as you can see, these two tables have a one-to-one relationship.

However, it regular_rulesalso has a one-to-many relationship with another table ( rule_coupons), which should also be combined.

So I have the following query:

SELECT `main_table`.*, `primary_coupon`.`code`, `regular_rules`.*
FROM `extended_rules` AS `main_table`
LEFT JOIN `rule_coupons` AS `primary_coupon`
    ON main_table.rule_id = primary_coupon.rule_id AND primary_coupon.is_primary = 1
LEFT JOIN `regular_rules`
    ON `main_table`.`rule_id` = `regular_rules`.`rule_id`

It looks great to me. However, I get the following error message:

SQLSTATE [42S22]: : 1054 "main_table.rule_id" "on"

, , , main_table.rule_id . , , , , , , -, .

, ( rule_coupons) ( regular_rules) .

: ... phpMyAdmin , . PHP script mysqli, . , (Magento). Magento, , ... , , .

+3
2

, .

, SQL , . , . , , - , .

, . , , "" , , ... , !

, , , , . , .

+1

: ON:

SELECT `extended_rules`.*, `rule_coupons`.`code`, `regular_rules`.*
FROM `extended_rules`
LEFT JOIN `rule_coupons`
    ON (extended_rules.rule_id = rule_coupons.rule_id AND rule_coupons.is_primary = 1)
LEFT JOIN `regular_rules`
    ON (`extended_rules`.`rule_id` = `regular_rules`.`rule_id`)

, , : MySQL, , , , . ; -)

+2

More articles:


All Articles