MySQL Left outer join with where clause - mysql

Question

I am trying to use the following MySQL query:
SELECT *
FROM top_lines t
LEFT OUTER JOIN last_24_topline AS l ON l.`member_no` = t.`member_no`
AND l.`mfg` = t.`line_no`
WHERE l.account_no = 32049 OR l.account_no IS NULL
However this is returning no rows, as there are no account_no rows in last_24_topline that match. From all that I understand and have read this query should still return all the rows from top_lines, even though no rows match in last_24_topline since I am checking for a value or null, but it is not. Are there any options or settings in MySQL (5.7.2) that would cause this behavior?
Just for information, this query works as expected:
SELECT *
FROM top_lines t
LEFT OUTER JOIN last_24_topline l ON l.`member_no` = t.`member_no`
AND l.`mfg` = t.`line_no`
AND l.`account_no` = 32049
I'm unable to use this construct however since I am using entity framework and you can only pass columns in and not values to the joins
CREATE TABLE `last_24_topline` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`member_no` varchar(30) NOT NULL,
`branch_no` int(11) DEFAULT NULL,
`employee_no` varchar(25) DEFAULT NULL,
`account_no` varchar(25) DEFAULT NULL,
`salesperson_name` varchar(255) DEFAULT NULL,
`customer_name` varchar(255) DEFAULT NULL,
`mfg` varchar(5) DEFAULT NULL,
`mfg_description` varchar(255) DEFAULT NULL,
`last_three` decimal(10,2) DEFAULT '0.00',
`last_twelve` decimal(10,2) DEFAULT '0.00',
`ly_last_three` decimal(10,2) DEFAULT '0.00',
`ly_last_twelve` decimal(10,2) DEFAULT '0.00',
PRIMARY KEY (`id`),
KEY `ix_branch_no` (`branch_no`),
KEY `ix_employee_no` (`employee_no`),
KEY `ix_member_line_account` (`member_no`,`mfg`,`account_no`),
KEY `ix_member_line` (`member_no`,`mfg`),
KEY `ix_account_no` (`account_no`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
CREATE TABLE `top_lines` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`member_no` varchar(30) NOT NULL,
`line_no` varchar(5) NOT NULL,
`line_description` varchar(255) NOT NULL,
PRIMARY KEY (`id`),
KEY `ix_line_no` (`member_no`,`line_no`)
) ENGINE=InnoDB AUTO_INCREMENT=41 DEFAULT CHARSET=latin1
insert into `top_lines`(`id`,`member_no`,`line_no`,`line_description`) values (1,'520','772','FED ROTOR/DRUM');
insert into `top_lines`(`id`,`member_no`,`line_no`,`line_description`) values (2,'520','952','FED SST CERAMIC');
insert into `top_lines`(`id`,`member_no`,`line_no`,`line_description`) values (3,'520','954','FED SST FRICTION');
insert into `top_lines`(`id`,`member_no`,`line_no`,`line_description`) values (4,'520','162','EVS FRICTION');
INSERT INTO `last_24_topline` (`id`, `member_no`, `branch_no`, `employee_no`, `account_no`, `salesperson_name`, `customer_name`, `mfg`, `mfg_description`, `last_three`, `last_twelve`, `ly_last_three`, `ly_last_twelve`) VALUES('1','520','0','10856','463854','FORD, JAMES,','JIFFY LUBE','459','FEDERATED AIR FILTER','0.00','15.21','0.00','0.00');
INSERT INTO `last_24_topline` (`id`, `member_no`, `branch_no`, `employee_no`, `account_no`, `salesperson_name`, `customer_name`, `mfg`, `mfg_description`, `last_three`, `last_twelve`, `ly_last_three`, `ly_last_twelve`) VALUES('2','520','0','10856','463854','FORD, JAMES,','JIFFY LUBE','460','FILTERS','0.00','0.00','0.00','16.48');
INSERT INTO `last_24_topline` (`id`, `member_no`, `branch_no`, `employee_no`, `account_no`, `salesperson_name`, `customer_name`, `mfg`, `mfg_description`, `last_three`, `last_twelve`, `ly_last_three`, `ly_last_twelve`) VALUES('3','520','0','10856','463854','FORD, JAMES,','JIFFY LUBE','863','SMP T SERIES','0.00','0.00','0.00','50.67');
I would expect, even with no data in last_24_topline that matches, for the first query to produce a result set containing all the rows in top_lines with null values for the columns from last_24_topline.
Expected results:
So, creating the same schema into another database and inserting only the example data I provided above, I get the results I expect. I am testing further with copying the full rows to the second database to see if it still gives the expected results.
update
Copying all data into the new tables causes the problem to resurface. I'm trying to pare down to the minimum necessary to replicate the issue.

Answer 1

Try detecting for empty string too, maybe the fields are not NULL, but empty strings.
SELECT *
FROM
top_lines t
LEFT JOIN
last_24_topline AS l ON l.member_no = t.member_no AND l.mfg = t.line_no
WHERE
(l.account_no = '' OR l.account_no = '32049' OR l.account_no IS NULL)
If you want more help, i will need a sample data for "table last_24_topline" and the expected output after the join.
As a second try, you can use this one:
SELECT *
FROM
top_lines t
LEFT JOIN
last_24_topline AS l ON l.member_no = t.member_no AND l.mfg = t.line_no
WHERE
l.id IS NULL
OR
(l.id IS NOT NULL AND l.account_no = '32049')

Answer 2

Use a column involved in the join instead of l.account_no this way rows from top_lines will be returned if there is no matching row in the left table.
SELECT *
FROM top_lines t
LEFT OUTER JOIN last_24_topline AS l ON l.`member_no` = t.`member_no`
AND l.`mfg` = t.`line_no`
WHERE l.account_no = 32049 OR l.`member_no` IS NULL
Alternatively place the account number filter directly in to the join
SELECT *
FROM top_lines t
LEFT OUTER JOIN last_24_topline AS l ON l.`member_no` = t.`member_no`
AND l.`mfg` = t.`line_no`
AND l.account_no = 32049

Answer 3

On the query without the account number in the join, the join does match row in the last_24_toplines table, but it does not match the account number in the where clause, so it is filtered out and not seen as a row from top_lines without a matching row from last_24_topline.
So, for example this row from the top_line table
Will match this row from the last_24_toplines
but both will then be filtered out, because the account_no didn't match what was in the where clause: WHERE l.account_no = 32049 OR l.account_no IS NULL
The query with the check for account_no within the join will still match the row from top_line, but will not have a matching row from last_24_topline, so you will get a row with top_lines data with null last_24_topline.