I have two tables name users , user_friends. user has over 10 million records and user_friends has more then 600 million records. The problem is that it does not have a constraint . i.e when a user is deleted their…
Let's say I have a student table like this: ID Name Major Gender 1 Alice Math F 2 Bob Biology M 3 Candice Econ F And I have a list of data like this: names=["Alice,"Bob","Candice"] majors=["Math","Biology","Econ"] genders="["F","M","F"] I want to…
CREATE TABLE t (STUDENT int, SCORE int, DATE date) ; INSERT INTO t (STUDENT, SCORE, DATE) VALUES (1, 6, '2022-02-01 00:00:00'), (1, 2, '2022-03-12 00:00:00'), (1, 5, '2022-04-30 00:00:00'), (2, 2, '2022-04-12 00:00:00'), (2, 0, '2022-04-17 00:00:00'), (2, 7, '2022-05-08…
I have a query like this: SELECT DISTINCTROW customers.id, customers.customer_name FROM customers INNER JOIN rentals ON customers.id = rentals.id_customer INNER JOIN rentals_billing ON rentals.id = rentals_billing.id_rental INNER JOIN vehicles ON vehicles.id = rentals.id_vehicle WHERE (rentals_billing.customer_id_facsimile IS NULL AND rentals_billing.rental_payable =…
I have a table with some columns : Id Active timestamp 1 TRUE 23-09-10 2 NULL 23-09-11 3 FALSE 23-09-12 4 TRUE 23-09-15 5 NULL 23-09-16 I want to order my results according to this priority order If boolean is…
I am new to programming and still learning. I have a project which is developed using PHP and MySQL. I'm facing an issue in SQL where I wanted to drop the primary key for the table I created. It would…
i need to create 2 additional columns from data in another column in the same table. i have a columns called Role, specifying different roles, e.g. Supervisor, Administrator, etc. Now i want to create a column for Supervisor and a…
We have just started with springboot. I did all of the steps my professor has shown, but it does not seem to be creating a database. **Application** spring.datasource.url = jdbc:mysql://localhost:3306/dbLastNameDemo spring.datasource.username = root spring.datasource.password = password spring.jpa.database-platform = org.hibernate.dialect.MySQL5InnoDBDialect spring.jpa.hibernate.ddl-auto…
I'm trying to save all the information inserted by user into database, all the info are able to save except the pdf file. My code: usermanual.php <div id="usermanualModal" class="modal fade"> <div class="modal-dialog"> <form method="post" enctype="multipart/form-data" id="usermanualForm"> <div class="modal-content"> <div class="modal-header">…
I need someone expert advice here. For my chat application, I'm using MYSQL. As I have structured messages so I chose mysql. Now My concern is about the scalibility and throughput. I spent time analizing DynamoDB in terms of scalibility…