What is the difference between a natural join and an inner join? Answer One significant difference between INNER JOIN and NATURAL JOIN is the number of columns returned. Consider: The INNER JOIN of TableA and TableB on Column1 will return The NATURAL JOIN of TableA and TableB on Column1 will return: The repeated column is avoided. (AFAICT from the standard
Tag: join
how to avoid duplicate on Joining two tables
This result is 2 times A even after using disticnt . My expected result will have only one A. if i remove row_number() over() as rownum its working fine. Why this is happening ? how to resolve. AM using DB2!! Answer There are two rows in marks Table with id = 1 and mark = 50.. So you will get
Count number of occurrences in SQL
I have a table with the following structure: (table_name, column_name) and for each row in this table I need to query the column_name in the table_name and do a COUNT(column_name) GROUP BY …
Complex JOIN with ActiveRecord and Rails 3
I have the following models: I have to find all posts that belong to groups where user is a member. I have made it with this method: but it produces unefficient SQL: I want to make a query like this: How can I do this without using raw SQL? Answer something like this should work for you, although it requires
SQL statement to get all customers with no orders
I have a typical Persons table and an Orders table defined in such a way that I can do JOIN query as the following to return Orders for all Persons. The question is, how do I write a statement that would return all Persons with NO Orders? I’m using mysql. Thank all in advance. Answer You may want to use
Left Outer join and an additional where clause
I have a join on two tables defined as a left outer join so that all records are returned from the left hand table even if they don’t have a record in the right hand table. However I also need to include a where clause on a field from the right-hand table, but…. I still want a row from the
Oracle join query
There are three tables in my db: ITEM_MASTER, PRICE_MASTER and COMP_MASTER. ITEM_MASTER STORE_CODE ITEM_CODE ITEM_DESC 011 914004 desccc PRICE_MASTER STORE_CODE ITEM_CODE COMP_CODE …
Join one row to multiple rows in another table
I have a table to entities (lets call them people) and properties (one person can have an arbitrary number of properties). Ex: People Properties I would like to write an efficient select that would select people based on age and return all or some of their properties. It’s also acceptable to return one of the properties and total property count.
SQL Inner Join On Null Values
I have a Join Isnull in a Join like this makes it slow. It’s like having a conditional Join. Is there any work around to something like this? I have a lot of records where QID is Null Anyone have a work around that doesn’t entail modifying the data Answer You have two options or easier
Inner Join two tables when one column is a text and the other is number
I have a program in access that is using some linked ODBC tables. I had originally had a query that contained the following INNER JOIN: This worked just fine until the column Neptune_prem.premice_id got changed from a number to a text data type. So now I need a way to use an INNER JOIN on two columns when one is