For SQL, when did it start to be desirable to always use the words "Inner Join" instead of implicitly joining by: select * from t1, t2 where t1.ID = t2.ID; ? Is it just for style or to distinguish between outer join or are there other reasons for it? ...
If an Inner Join can be thought of as a cross join and then getting the records that satisfy the condition, then a LEFT OUTER JOIN can be thought of as that, plus ONE record on the left table that doesn't satisfy the condition. In other words, it is not a cross join that "goes easy" on the left records (even when the condition is not sa...
I have a DB which has a table called config. This table could possibly have a config_cstm table that is related by the id to the config table. I was wondering - is there a way to dynamically check for the existence of this table in one simple select statement? In other words, something like: select * from config (IF EXISTS config_...
I would like to try using Outer Join to find out duplicates in a table: If a table has Primary Index ID, then the following outer join can find out the duplicate names: mysql> select * from gifts; +--------+------------+-----------------+---------------------+ | giftID | name | filename | effectiveTime | +--------+--...
I have three tables Prospect -- holds prospect information id name projectID Sample data for Prospect id | name | projectID 1 | p1 | 1 2 | p2 | 1 3 | p3 | 1 4 | p4 | 2 5 | p5 | 2 6 | p6 | 2 Conjoint -- holds conjoint information id title projectID Sample data id | title | projectID 1 | color | 1 2...
What is the difference between between Left Join and Left Outer Join? ...
I have two tables that were built for two disparate systems. I have records in one table (called "leads") that represent customers, and records in another table (called "manager") that are the exact same customers but "manager" uses different fields (For example, "leads" contains an email address, and "manager" contains two fields fo...
I need make OUTER JOIN of two entities in JPA (saying master, detail), but the problem that at the entity level there are no relations (and i don't want add it). @Entity class Master { @Column(name="altKey") Integer altKey; } @Entity class Detail { @Column(name="altKeyRef") @Basic (optional = true) Integer altKeyRef...
I'm looking up access logs for specific courses. I need to show all the courses even if they don't exist in the logs table. Hence the outer join.... but after trying (presumably) all of the variations of LEFT OUTER, RIGHT OUTER, INNER and placement of the tables within the SQL code, I couldn't get my result. Here's what I am running: ...
I am new to LINQ and am trying to convert a SQL query to LINQ: SQL: left outer join PRODUCT_BEST_USE pbu on pbu.PRODUCT_GUID = @uProductId and pbu.BEST_USE_GUID = bu.BEST_USE_GUID LINQ: from PBU in PRODUCT_BEST_USE.Where(PBU=>PBU.PRODUCT_GUID == p.PRODUCT_GUID).DefaultIfEmpty() When I add and PBU.BEST_USE_GUID equals BU.BEST_U...
There are two models Post and Comment. I should get all posts, which have no comments with specific tag. How can I do this using new Rails 3 features such relational algebra (arel). SQL-solution should be something like this: SELECT `posts`.* FROM `posts` LEFT OUTER JOIN `comments` ON `posts`.`id` = `comments`.`post_id` WHERE...
hi, i'm using nHibernate 2.1.2 and relized that nhibernate will generate left outer join on nested many-to-one entities. it seems start generate left-outer-join on 3rd nested note onwards which start from entity Organization. i have set following in the mapping file to force use inner-join, has anything i missed out in the mapping file?...
Works: AND UPPER(a.name) = b.lname(+) does not work AND UPPER(a.name) = UPPER(b.lname) (+) Moving to ANSI joins is an option but a painstaking one. This code should be changed in lot of places and there are lot of joins. I would like to get this syntax correct and be on my way. Is it possible? ...
Hi, I have an issue in understanding a very simple yet interesting query concerning 2 right outer joins with 'non-sequential' on-expressions. Here is the query: select * from C right outer join A on A.F1 = C.F1 right outer join B on B.F1 = C.F1; Here are the tables: create table A ( F1 varchar(200)); create table B ( F1 varchar(...
I may have have the wrong end of the stick here, but I thought that an outer join was supposed to give me all the records that were in either the (say) left table, along with the matching results from the right table, and nulls where there was no match. I have 3 tables I need to query. Person and Detail have a direct 1:1 relationship. ...
As per http://stackoverflow.com/questions/3264227/relations-with-multiple-keys-in-doctrine-1-2, I have two tables which (as I can't get it to work in Doctrine) I'm trying to join as a MySQL view: part: part_id product_id part_type_id part_short_code ... part_translation: part_type_id part_short_code language_id internationalised_n...
According to Google search: since MySQL does not support full outer join, it could be simulated via union and/or union all. But both of these either remove genuine duplicates or show spurious duplicates. What would be correct and efficient way? This question seems relevant but couldn't get the answer of it. ...
Hi, I have two tables like this. Table1 Column | Type | ---------+------------------+ cod | text | value99 | double precision | Table2 Column | Type | ---------+------------------+ cod | text | value06 | double precision | and i'd like to join them so i'd have somethi...
Outer joins seem to me a little bit confusing. Is there anyone can get me a clear picture of outer joins (right, left and full)? ...
I'm not sure how to describe my table structure, so hope this makes sense... I have 3 tables in hierarchical relationship such that A has a one to many relationship to B which in turn has a one to many relationship with C. The trick is that the foreign key in B and C are allowed to be null (i.e. no parent defined). I also have D and E...