I want the solution like each item id all messages between sender and receiver and need all rows belongs to user i.e. if sender id = 3 and receiver id = 25 then it will list out all message of…
I want to select only those identifiers from a table which are contained in another subquery result and only top-2 rows must be used. For example you can run the query on PG: select a.rid from( values (41), (42), (43),…
I am using the sample Northwind DB and would like to INSERT a new product for every discontinued product and renaming the new product with an appended '_v2'. Problem is I would like to specify a new ProductID (for a…
I have a simple subquery in MySQL which produces a set of codes, something like 'LPR','LFR','LFL' (more codes can be returned). Using this in my main query slows it right down, like it can take a minute or 2 to…
I handle articles on a multi-language site, with the possibility for the users to update the content. I use a MySQL database. Table articles: id Table article_contents: id article_id (FK) content lang version If the new content is still a…
I am practising SQL on leetcode (Using MySQL) and came across the following problem - where I am confused on why my solution does not work. The following is an employee table where it shows which department(s) an employee is…
I have these SQL queries: EXPLAIN ANALYZE SELECT * , ( SELECT COUNT(*) FROM orders WHERE orders.customer_id = customers.id ) as orders_count FROM customers LIMIT 10 The execution plan for this query: EXPLAIN ANALYZE SELECT * , ( SELECT COUNT(*)…
I have attendance table like this: Employee Date_Time Status std001 2024-02-01 22:01:00 IN std001 2024-02-02 06:00:05 OUT std001 2024-02-03 07:59:00 IN std001 2024-02-03 17:00:00 OUT std001 2024-02-04 06:00:00 IN std001 2024-02-04 14:00:00 OUT I want to select the table above…
I have questions about sub query. I have table: Emp_ID Date_Entry Clock_In Clock_Out E-0001 2024-02-01 2024-02-01 22:01:00 NUll E-0001 2024-02-02 NULL 2024-02-02 06:01:05 E-0001 2024-02-03 2024-02-03 06:01:00 2024-02-03 14:00:20 E-0001 2024-02-04 2024-02-04 08:00:00 2024-02-04 17:01:05 how to query with mysql…
We have this query that is running: SELECT concat_ws(' ', z.ticker, CASE WHEN a.date_approved IS NOT NULL THEN TO_CHAR(a.date_approved,'YYMMDD') WHEN z.date_recommended IS NULL THEN '000000' ELSE TO_CHAR(z.date_recommended,'YYMMDD') END, CASE WHEN s.ticker IS NOT NULL THEN 6 WHEN a.approved_recommendation IS NOT…