as shown in the figure, a simple add and query operation takes up to 1 second [environment: windows + python3 + django2]. (the amount of data in PS: is not much, and todo_list has only 2 rows of data, which is still so slow.) def get(request): -...

Table T_USER T_ROLE : the following is the table creation and data script drop table if exists T_USER; CREATE TABLE T_USER( USER_ID INT, USER_NAME VARCHAR(25) ); INSERT INTO T_USER VALUES(1, USER_A ); INSERT INTO T_USER VALUES(2, USER_B )...

for example, go connection mysql, https: github.com jmoiron sqlx is a client that implements official database sql, and an additional driver: https: github.com go-sql-dri. is required to use it. but this is not the case when I connect to mongodb. ...

after reading this article (introducing schema in the database) https: www.biaodianfu.com da., it is mentioned that the schema in MySQL is the same as the library. Is this correct? Thank you ....

what do you mean by sub-database and sub-table partitioning of the database? ...

take MySQL as an example, what is the difference (principle and efficiency) between in and exists and between not in and not exists? What about using indexes? Say that not in and < > will not use indexes, won t you? ...

recently, I have been learning distributed architecture. I have basically figured it out. What about the database? the mysql, I ve been using take mysql as an example for example, I now have two databases of server B. According to the load balancer,...

1. How to decompose (A, B)-> E, (C, D)-> E, A-> C, C-> An into BCNF,? 2, U = (Agraine Brecinct C pyrrhene E) F = {B-> Greco ce-> Breco C-> Areco B-> Dle le C-> D}. Decompose into BCNF? 3. The BCNF decomposition that I understand at present is to fin...

for example: < table > < thead > < tr > < th > id < th > < th > num < th > < tr > < thead > < tbody > < tr > < td > 1 < td > < td > 1 < td > < tr > < tr > < td > 2 < td > < td > 20 < td > < tr > < tr > < td > 3 < td > < td > 30 < ...

in development, there are some scenarios where we need to store information for a time period in the database. For example, an event has a start time and an end time, and we can store it in the database with two fields such as startDate and endDate. But...

CREATE OR REPLACE PROCEDURE QD_MYDTJ (BEGINDATE VARCHAR2, ENDDATE VARCHAR2, xz_name VARCHAR2, xz_number VARCHAR2, --BEGININTEVAL VARCHAR2, --ENDINTEVAL VARCHAR2, start1 IN NUMBER, limit1 IN NUMBER, AN_O_RET_CODE ...

is there a book to improve abstraction in designing database tables according to requirements? ...

Please see here expression of successful query if ($conn->query($sql) === TRUE) { echo ""; } else { echo "Error: " . $sql . "<br>" . $conn->error; } Please see my code: <form action=""...

or answer my question directly: when a sql of select has a primary key and an index, what is the order of its execution? is there a big god to find it first from the primary key or from the index? ...

topic description at present, there is a product that the user places an order to reduce inventory, the order is cancelled to increase inventory, and the backend modifies the inventory quantity. There are three different ways to do this. How about S...

question: select * from table where created_at > where is the problem? How to solve? answer: time writes dead, closes, time opens, there must be closing time. The question is, why should it be a closed interval when querying this time field? It ...

there is data in every table, but it is 112KB and there is no .frm file. What is this all about? ...

how to deal with fields with unique indexes in the case of sub-tables? there is no guarantee of constraints when adding new ones ...