Table rows into columns in mysql - mysql

Question

Say I have a database similar to the following:
Table events_degree:
event_id degree_id
1 1
1 31
... ...
Table events_area:
event_id area_id
1 1
1 31
... ...
Table events_schedule:
event_id schedule
1 Time 1
1 Time 2
... ...
Table events:
id name
1 prom
2 homecoming
... ...
Table degree:
id name shortened
1 computer science cs
2 something else se
... ... ...
Table area:
id name
1 hall 1
2 gym
... ...
Table building:
id name
1 main building
2 second building
... ...
What i want to do it's merge the columns since i have this query
SELECT `e`.*, `eh`.`start_date`, `eh`.`end_date`, `c`.`name` AS `degree_name`, `c`.`shortened` AS `shortened_degree`, `ai`.`name` AS `area_name`, `ed`.`name` AS `building_name`
FROM `events` `e`
LEFT JOIN `event_schedule` `eh` ON `e`.`id` = `eh`.`event_id`
LEFT JOIN `event_degree` `ec` ON `e`.`id` = `ec`.`event_id`
LEFT JOIN `degree` `c` ON `c`.`id` = `ec`.`degree_id`
LEFT JOIN `event_area` `ea` ON `e`.`id` = `ea`.`event_id`
LEFT JOIN `area` `ai` ON `ai`.`id` = `ea`.`area_id`
LEFT JOIN `building` `ed` ON `ed`.`id` = `ai`.`building_id`
WHERE `e`.`active` = '1'
AND `eh`.`start_date` >= '2016-03-08'
AND `eh`.`end_date` < '2016-07-01'
ORDER BY `eh`.`fecha_inicio` ASC;
and as a result i get all the rows "duplicated" as you can see in the picture
how can i avoid this, thanks for your help
** note **
it's the same event so it should be displaying only 1 row for every event the problem is that i has 3 many to many relationships
so the things that change are only dates, degrees and areas

Answer 1

You can use GROUP BY
SELECT DISTINCT `e`.*, `eh`.`start_date`, `eh`.`end_date`, `c`.`name` AS `degree_name`, `c`.`shortened` AS `shortened_degree`, `ai`.`name` AS `area_name`, `ed`.`name` AS `building_name`
FROM `events` `e`
LEFT JOIN `event_schedule` `eh` ON `e`.`id` = `eh`.`event_id`
LEFT JOIN `event_degree` `ec` ON `e`.`id` = `ec`.`event_id`
LEFT JOIN `degree` `c` ON `c`.`id` = `ec`.`degree_id`
LEFT JOIN `event_area` `ea` ON `e`.`id` = `ea`.`event_id`
LEFT JOIN `area` `ai` ON `ai`.`id` = `ea`.`area_id`
LEFT JOIN `building` `ed` ON `ed`.`id` = `ai`.`building_id`
WHERE `e`.`active` = '1'
AND `eh`.`start_date` >= '2016-03-08'
AND `eh`.`end_date` < '2016-07-01'
GROUP BY `your_id`;

Answer 2

Use DISTINCT while selecting
SELECT DISTINCT `e`.*, `eh`.`start_date`, `eh`.`end_date`, `c`.`name` AS `degree_name`, `c`.`shortened` AS `shortened_degree`, `ai`.`name` AS `area_name`, `ed`.`name` AS `building_name`
FROM `events` `e`
LEFT JOIN `event_schedule` `eh` ON `e`.`id` = `eh`.`event_id`
LEFT JOIN `event_degree` `ec` ON `e`.`id` = `ec`.`event_id`
LEFT JOIN `degree` `c` ON `c`.`id` = `ec`.`degree_id`
LEFT JOIN `event_area` `ea` ON `e`.`id` = `ea`.`event_id`
LEFT JOIN `area` `ai` ON `ai`.`id` = `ea`.`area_id`
LEFT JOIN `building` `ed` ON `ed`.`id` = `ai`.`building_id`
WHERE `e`.`active` = '1'
AND `eh`.`start_date` >= '2016-03-08'
AND `eh`.`end_date` < '2016-07-01'
ORDER BY `eh`.`fecha_inicio` ASC;