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Tag: left-join

Postgres LEFT JOIN not returning nulls?

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

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

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 without ORDER BY is fairly meaningless, because you aren’t telling MySQL which order to

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 and the query does look optimized. For this I have

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