left-join

why this left join query failed to load all the data in left table ?

users table +-----+-----------+ | id | username | +-----+-----------+ | 1 | tom | | 2 | jelly | | 3 | foo | | 4 | bar | +-----+-----------+ groups table +----+---------+-----------------------------+ | id | user_id | title | +----+---------+-----------------------------+ | 2 | ...

Remove Duplicates from LEFT OUTER JOIN

Hey folk my question is quite similar to http://stackoverflow.com/questions/757957/restricting-a-left-join I have a variation in that request though and the comment didn't allow too many characters hence posting as a new question. I hope this doesn't go against the posting rules/etiquette. Assuming i have a table SHOP and another tabl...

How sql server evaluates the multiple different joins?

Hi, i have a general question about how sql server evaluates the joins.The query is SELECT * FROM TableA INNER JOIN TableB ON TableB.id = TableA.id LEFT JOIN TABLEC ON TABLEC.id = TABLEB.id Q1: What tables is the left join based on? I know it will based on the TABLEC but what is the other one? Is it the result of the first inner jo...

INNER or LEFT Joining Multiple Table Records Into A Single Row

Phone Table +----------------+-------------+ | Field | Type | +----------------+-------------+ | f_id | int(15) | | f_client_id | int(11) | | f_phone_type | varchar(50) | | f_phone_number | varchar(13) | +----------------+-------------+ Clients Table +-----------------------------+------------...

SQL Oracle LEFT JOIN and SUBQUERY error: ORA-00905: missing keyword

Hello everyone. Asking for your help on this Oracle query. It's giving me the error 2 "ORA-00905: missing keyword". It was working fine before I added the LEFT JOIN statement. Obviously it won't deliver the information as we need it without the LEFT JOIN statement. Please provide any help to know which keyword is missing in this query ...

Broken count(*) after adding LEFT JOIN

Since adding the LEFT JOIN to the query below, the count(*) has been returning some strange values, it seems to have added the total rows returned in the query to the 'level': SELECT `n`.*, exp_channel_titles.*, round((`n`.`rgt` - `n`.`lft` - 1) / 2, 0) AS childs, count(*) - 1 + (`n`.`lft` > 1) + 1 AS level, ((min(`p`.`rgt`) - `n`.`...

MySql left join on several regs

Hi there! I have this table1 idproduct(PK) | date_to_go 1 2010-01-18 2 2010-02-01 3 2010-02-21 4 2010-02-03 and this other table2 that controls date_to_go updates id | idproduct(FK) | prev_date_to_go | date_to_go | update_date 1 1 2010-01-01 2010-01-05 ...

MySQL LEFT JOIN issue with three WHERE statements

I am building a note taking app for myself with tag filtering functions, but am having an issue when trying to grab notes with the tags. The tag filter needs to use AND not IN, because it will help better narrow down what I am looking for. My tables are configured like this: + notes note_id | note_title | note_uid + tags...

Need a rough estimate on how long LEFT JOIN on two 6 million row tables would take.

Hello, well the title says it all. Does anyone have an idea? Would need to lock the table for that long on production site, so it is kinda important. Also, do you have any suggestion how such query could be optimized? Thanks! ...

SQL: Gather right hand values from a join

Let's say a question has many tags, via a join table called taggings. I do a join thus: SELECT DISTINCT `questions`.id FROM `questions` LEFT OUTER JOIN `taggings` ON `taggings`.taggable_id = `questions`.id LEFT OUTER JOIN `tags` ON `tags`.id = `taggings`.tag_id I want to order the results according to a particular tag nam...

convert sql to linq sample

Hello, I've got a sql statement, but I can't get it working in linq. Can someone show me how I can write the following sql statement as linq? SELECT * FROM mobileApplication LEFT JOIN videoMobile ON mobileApplication.id = videoMobile.mobileApplicationId AND videoMobile.videoId = 257 It's a left join with a where statement on th...

Hibernate: Perform criteria query with Sub-Select AND Left-Outer join?

Can I perform a Criteria query with Sub-Select AND Left-Outer join? For example, I have A 1-many B 1-many C. With Criteria.createAlias ("b", "b", Criteria.LEFT_JOIN) I can perform Left Outer join. With Criteria.setFetchMode ("b", org.hibernate.FetchMode.DEFAULT) I can perform Join with the default fetching strategy. I assume that hav...

mysql filtering result using left outer join

my query: SELECT content.*, activity_log.content_id FROM content LEFT JOIN activity_log ON content.id = activity_log.content_id AND sess_id = '$sess_id' WHERE activity_log.content_id IS NULL AND visibility = $visibility AND content.reported < ".REPORTED_LIMIT." AND conte...

SQL left join automatic aliasing?

I just realized that I'm going to have to start aliasing my database calls due to repeating column names in my join tables. Is there a way to automatically tell SQL to alias all my column names so that they are returned with a prefix of the table name? Otherwise it appears to be quite confusing when only some of them are aliased. Just ...

How to optimise MySQL query containing a subquery?

I have two tables, House and Person. For any row in House, there can be 0, 1 or many corresponding rows in Person. But, of those people, a maximum of one will have a status of "ACTIVE", the others will all have a status of "CANCELLED". e.g. SELECT * FROM House LEFT JOIN Person ON House.ID = Person.HouseID House.ID | Person.ID | Person...

What are some good examples where SQL's OUTER JOIN is used?

I often get asked the questions in an interview that "what is an outer join in SQL"? While it can be answered, I wonder what might be some classic and good real life examples where a (LEFT) OUTER JOIN is used? ...

Left Join not returning all rows

I have this query in MySQL: SELECT pr.*, pr7.value AS `room_price_high` FROM `jos_hp_properties` pr LEFT OUTER JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id WHERE pr7.field=23 The jos_hp_properties table has 27 rows but the query only returns one. Based on this question I think it may be because of the WHERE clause. The jos_hp_p...

Display a ranking grid for game : optimization of left outer join and find a player

Hello, I want to do a ranking grid. I have a table with different values indexed by a key: Table SimpleValue : key varchar, value int, playerId int I have a player which have several SimpleValue. Table Player: id int, nickname varchar Now imagine these records: SimpleValue: Key value playerId for 1 1 int ...

How to join 1 table twice in the same query and keep results separate

Hi, we're building a scheduler system and have a couple of situations where we're trying to get some notes from a table to display. We've looked at other answers and none seem to quite match this problem. The bookings table holds a numeric reference to both a client note (if present) and a stylist note (if present). The notes table ho...

Help with MySQL Query?

I have two tables rooms and users. I want to get only rooms.room_id, users.user_name with user_id = 1. I can get the result of all users with following sql... select rooms.room_id, rooms.user_id, users.user_name from rooms LEFT JOIN users ON rooms.user_id = users.user_id When I do like this to filter the result with...