Not sure why this is happening, but I have this query: And the item table has 100 elements. I’m looking for the resulting rows to be grouped by user_id and have each array be 100 items long. That is, if the value is not present in the vote table, to just instead sub in a 0 in its place. Unfortunately
Tag: left-join
Try to define a left join only with where condition
I try to find a particular SQL statement to replace an old SQL query. To summarize, I try to make a left join only with where conditions. Here is my test environment: I fill the tables with some data: The usual way for a left join is this: This query returns 1266 rows. But in the old application, which I
SQL: join on foreign key between two tables and return only count of items; not actual items
I know there’s lots of questions similar to this out there. I’m writing my first SQL query; and I’ve been looking through SO but I can’t find out specifically what I’m doing wrong, because to me, they …
Select unmatched records from two tables with a filter on second table
I have 2 mysql tables a and b. I need to show all records in a that are not in b using a common column ‘ID’. Normally this is pretty straight forward but my problem here is this: I need to put a where clause on table b because I’m not interested in all unmatched records just the ones that
Left Join return not all row
I have two tables: baseresulttables and historyviewdemands. I want to get the first n entries from baseresulttables, and if there are values for them in historyviewdemands. But the query works like an inner join. What am I doing wrong? baseresulttables historyviewdemands Query: reuslt Answer Using LIMIT witho…
How to get average value using LEFT JOIN in LINQ and Lambda
I want to display each book average rating with its publisher using LINQ and Lambda. Here’s my book list private List Books = new List(){ new Book { Id: 1, Name: Book A, …
Query to Id referencing to an ‘Id’ to the same table
I have a table AMZ_EMPLOYEE_DETAILS with Employee Id, Employee Name and Supervisor1 and Supervisor 2. The Supervisors are employee itself but represented by their name. My task was to replace the Supervisor names with their Ids. I have used the following query to obtain the solution but it uses sub-queries an…
SQL Server: hidden “Sort” inserted in execution plan in left join query
SQL 2017 Standard i have a database in a star schema model (data warehouse) to fill in a fact table, i have a stored procedure with a temporary table having around 470,0000 rows. to fill in the …
SQL Group rows in left join into one
i try create query with left join when i combine multiple rows into one. I try with GROUP_CONTENT function but when i try use it my db server is going down. I use MariaDB 10.3.17. I have tables like: …
Efficient way to map new values to a sql query (i.e 4 columns each with same credentials)
First I am new to Postgres so I may be describing this problem incorrectly so please point me to an answer if it has already been answered. I have a database with 10 columns. Lets say 4 columns all use the same codes for values (i.e the letter a, b, d, e) I want to rename all of these in