I have 2 tables that I join using LEFT JOIN, i.e. I take Name from table A and match it to Name from table B. There are some records that do not match and return null values due to it…
I will try my best to explain this. Let's say I have a table like this Name Year Present_category Present_count Mother Mary 2023 sweets 3 Linda Mary 2022 sweets 2 Linda Linda 2022 sweets 4 Linda 2021 sweets 1 Linda…
sample code SELECT b.title, i.barcode FROM biblio b JOIN items i ON b.biblionumber= i.biblionumber Join biblioitems bi ON i.biblionumber=bi.biblionumber where i.barcode IN (4088,6183,6191) above SQL given results as below, how do I get results in IN (4088,6183,6191) as entered order
Table 1 +--------+------------+-------+ | URI | Date | Name | +--------+------------+-------+ | Fred4 | 2023-04-05 | Fred | | Fred3 | 2023-04-01 | Fred | | Fred2 | 2023-03-15 | Fred | | Fred1 | 2023-03-06 | Fred | |…
I have the following database relationship and query for PostgreSQL below: create table gender( gender_id int primary key, gender char(10)) create table student( student_id int primary key, first_name char(50) not null, last_name char(50) not null, gender_id int not null, constraint…
I have the following movie database relationship diagram and used the queries below to create the tables and its keys as shown below: The following are the codes that I used to create these 4 tables and inserted the data:…
I have the following query: delete from customers_cards where id not in ( select min(id) from customers_cards group by number_card ) and belongs_to = "ezpay" It throws: #1093 - You can't specify target table 'customers_cards' for update in FROM clause…
I am trying to select with a join of a table, then use where to exclude some results, like this: SELECT * FROM table1 LEFT JOIN table2 ON table1.var = table2.var WHERE table1.var IN (select var from table3 WHERE var…
In a trading platform, users have three different actions: LOGIN, SEARCH, ORDER. Abandoned SEARCH action is defined as: customers LOGIN then do some SEARCH and do not ORDER before next LOGIN. Now I have a table: action_table, recording customer_id, action,…
Consider the following tables: create table `t1` ( `date` date, `value` int ); create table `t2` ( `date` date, `value` int ); insert into `t1` (`date`, `value`) values ("2022-01-01", 1), ("2022-03-01", 3), ("2022-04-01", 4); insert into `t2` (`date`, `value`) values…