your id MYSQL setting is numeric, but you are querying character types. At this point, MYSQL does an implicit conversion and does not use indexes. Where characters are converted to numbers:
sql statement
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do a check-in function `create_time` decimal(20,3) NOT NULL, `create_date_ymd` varchar(15) NOT NULL COMMENT , `create_date_ym` varchar(15) NOT NULL, `create_date_y` int(4) NOT NULL, `create_date_m` int(2) NOT NULL, `create_date_d` int(2) ...
like this SELECT * FROM material WHERE {key:value} limit 1 ...
I want to do a circular sequence to output pictures. Don t know how to write this code? Table structure for example, now the field ID of key=1 is 1, 2, 5, 7, 10, 11, 6 fields I want to output one at a time in order. output id 1 field for t...
firewall, the integrated environment of system Centos7, lnmp.org, does not have the permission to run mysql. Iptables has been restarted. Refresh authorization error: Mysql user:Iptables: New processing: 1. Modify mysql configuration file vi ...
if you currently need to generate a table each month to store the current month s data, the following table will be generated: tablename_201709 tablename_201710 tablename_201711 tablename_201712 tablename_201801 tablename_201802 tablename_201803 table...
scenario is that there are a series of post (news category) in the database. Now you want to sort according to the post_date in the post table (time), view (browsing), or the likeCount of the post_like table, and read the data in batches. The limit is 2...
the api I am talking to now is a request from others. is to use curl to catch the opposite party http. I give it to the opposite party json , and then the opposite party gives back to me json, and then I show it (using mongodb, nodejs) ). it s just t...
my mysql database has two pieces of data when I print_r, it looks like this: [{"errno":"1","errstr":"2","errfile":"3","errline":"4"},{"errno":"12",...
Field id is of type int select * from table where id= 1 ; select * from table where id=1; Is there any difference in execution efficiency between the two statements? Is the first line id calculated? I seem to be the same through explain, but why...
I want to create a table to store the configuration information of the website, but I don t need to add the whole ID into one column. What do you care about this kind of information? ...
such as now I want to design an online seat selection system but when users sign up, they can dynamically edit unreserved seats in the background how should I design it from the generation of seats to the final registration, seat selection and editing...
the effect to be obtained is [{ "name ": "aaa ", "id ": "1 ", "sex ", "man "}, { "name ": "bbb ", "id ": "2 ", "sex ", "woman "}, {}.] now the display is { "name ": "aaa ", "id ": "1 ", "sex ", "man "} { "name ": "bbb ", "id ": "2 ...
there is a requirement: A notice is sent to specify who can read it. the simplest solution to take advantage of mysql: message Information Table id Information ID name content < hr > message_user user View Information Table id message_id Inf...
In the high concurrency environment, I want to record the number of clicks per click. The database self-increasing field is id , but there is already a lot of data in it. You can t use id to identify the clicks. If there is any way of thinking, there w...
when I query a piece of data, I cannot query the data after using parameter binding: the following is the sql to be queried $sql = SELECT `id` FROM `ct_collection` where `issue`=:issue LIMIT 1 ; Parameter binding is: 050 SQL: [90] SELECT `id`...
Hello as shown in the following picture, the inventory table of the clothing industry like this, how to design the database, the color and size of each order may be different. ...
I wrote a query in thinkphp, but I couldn t find it out, and then I printed it out . shows that it is successful. I don t know what s going on. I ask for help from all the great gods . ...
one of my websites is php+mysql,. Now there is a problem. there are two data tables: an and B. Table A has 240000 items of data, and Table B now has 24000 items of data. extract 50 pieces of data from datasheet A, and then generate a html page. It t...
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ask, our company has only one space, there are English website and Chinese website. Now the code and database of Chinese website have been imported, and the English code has also been imported. Can the database of English website be imported? Many of the...
