outer-join

问题 I'm trying to get a list of products order by the amount sold and by date. I also want to display the products that haven't been sold in the list so I tried doing a subquery first but MYSQL is giving me this message: Operand should contain 1 column(s) SELECT product.product_id, product.product_brand_id, product.product_model_id, product.product_subcategory_id, product.product_retail_price, product.product_wholesale_price FROM product WHERE product.product_subcategory_id = $subcategory_id AND

问题 Say I have something like this: <div class="entry"> <a class="click" href="http://domain.com">Some link</a> </div> <div class="entry"> <a class="unclick" href="http://domain.com">Some link</a> </div> How would I target the entire contents of a .entry surrounding an a.click, without affecting the .entry surrounding of an a.unclick I want to hide the outer div if the link has a class of "click". EDIT: I need to do this without resorting to javascript, only CSS and HTML. 来源： https:/

问题 Let's say I have two Arrays in Ruby, containing user IDs. These are the old users: == old == 1 2 3 4 And these are the new: == new == 2 3 4 5 6 I want to find out the IDs of new users , so in that case, 5 and 6. I guess what I want is a left outer join of NEW and OLD, but I don't know how to do that with simple arrays. I'm relatively new to Ruby, so there might be a simple and effective solution for this, rather than iterating over everything. 回答1: old = [1, 2, 3, 4] new = [2, 3, 4, 5, 6] p

问题 I have two tables that are something like this: Main table: id (int), title (varchar), etc. Sub-table: main_table_id (foreign key into main table), tag (varchar), etc. There can be zero or more subtable rows for a given row in the main table. I want to do a query that will return every row of the main table, with the columns of the main table, and a the columns from only a single row (doesn't matter which) of the sub-table, if there are any, otherwise NULL in those columns. Of course if I

问题 I have a question about the using of (+)= in the where clause in Oracle database; a. id= b.id(+) Does that mean a left join that a left join on b where a.id=b.id, right? a.Job_Type(+) = 'Manager' I don't understand why he uses (+)= here, but not a.Job_Type = 'Manager', are they the same? 回答1: The (+) identifies the table that is being outer joined to. The way I was taught, the (+) indicated the table that would have missing rows for which new NULL rows had to be added. If you look at the

问题 I have multiple tables and the column fields and all match data type and column number wise, and all have a time field that also matches in the format of YYYY-MM-DD HH:MM:SS across all. Data Issue I may have tables where there is a date and time stamp with a matching value in that table's value column, but in the other table it'll not have that same date and time stamp since each table only logs a time when a value fromt he other field is generated. My Dilemma I need to join all these tables

问题 This is an extension of a question posted by me earlier which can be found here : Previous Question Now i have 2 more tables that are also connected to ProfileFan tracking the Activities of the Fan(ProfileFan). Table Fan ----------------------- | FanId | Name | Info | ----------------------- | 17111 | Fan1 | Info1| ----------------------- | 17112 | Fan2 | Info2| ----------------------- Table ProfileFan m:1 Fan FanId(FK) ----------------------------------- | Id | LinkedInProfileId | FanId | --

问题 Hi everyone I am currently working on an SQL sample project, trying to learn the basics of SQL and inner outer joins in general. This is my current Database diagram: http://imgur.com/z0Ger I am currently stuck on 2 different queries that I am having trouble writing. 1. Given a puppy name show all the tricks it knows. Include: Dog id & name Trick id & name Date learned & skill level 2. Given a kennel show all the puppies that have been there to learn a trick. Include: Kennel id & name Date

问题 I know the algorithm for a hash left outer join is to build a hashtable on the right table and then loop through the left table and search in the hashtable for if there is a match, but how does a full outer join work? After you scan through the values in the left table you would still need a way to get the tuples in the right table that didn't have matches in the left. 回答1: While looping through the probe records you record which right tuples have found a match in the build table. You just

问题 I am trying to migrate some legacy procedural code. I am having trouble figuring out the ANSI standard syntax to produce the same results. Below is one of the many combinations I have tried. What is the inner table for the second join, is it the output from the first join or is it the source table. Please help I have a lot of code to change. Original SQL Statement select * from JT1 a, JT2 b, JT3 c where a.ID *= b.ID and c.JOB *= b.JOB My Conversion select * from JT1 a left outer join JT2 b on