mysql find

MySQL find out how to tell if a field contains a string there is such a requirement in MySQL DatabaseIn a String field (permission), the user has several different mailboxes, separated by ', ', and now wants to take out all the member lists of a

Find the highest grades in each sectionCREATE TABLE Grademax (ID int primary KEY auto_increment,Name varchar (20),Subject varchar (20),Grade int);Insert into Grademax (name, subject, Grade) values(' dots ', ' language ', 100),(' Little black ', '

A, conditional judgment whereSELECT * FROM table where ID > 1 and name! = ' Alex ' and num = 12;select * FROM table where ID between 5 and 16;select * FROM table where ID in (11,22,33) select * FROM table where ID not in (11,22,33) select * FROM

Viewed as an example: the original data is as follows:Thinking Analysis: The data has, statistics on a day's views, all views, or a fixed period of browsing volume here we will not say more, we will, then how we are the last seven days of data

CREATE FUNCTION getchildlist (Rootid INT)RETURNS varchar (1000)BEGINDECLARE schildlist VARCHAR (1000);DECLARE schildtemp VARCHAR (1000);SET schildtemp =cast (Rootid as CHAR);While schildtemp are NOT NULL doesIF (Schildlist is isn't null) thenSET

Recently, someone in the group asked how to find an ID that does not exist in the MySQL table (id is self-increment, or can be continuous)The first method:Select Bewin_id,a from(Select bewin_id,1 as a from (select bewin_id from C_userinfo_his ORDER

There is such a table, the table data and the results are as follows: school_id School_name Total_student Test_takers 1239 Abraham Lincoln High School 55 50 1240 Abraham Lincoln High

1. Server-level lock waitsthe thread ID of the wait lock can be seen through show processlist, but there is no way to know exactly which thread holds the lockcan be mysqladmin by debug The associated thread waiting for the lock and who holds the

Mysqlhttps://dev.mysql.com/downloads/mysql/1. Connect MySQLFormat: mysql-h host address-u user name-P user Password1. Connect to MySQL on this machine.First open the DOS window, then enter the directory Mysql\bin, and then type the command Mysql-u

http://blog.csdn.net/k_scott/article/details/88043841. First check whether the profiling function is turned on[SQL]View PlainCopy SHOW VARIABLES like '%pro% '; Or[SQL]View PlainCopy SELECT @ @profiling; 2. Open

For example, a table contains three fields: product, price, and date: a10.2, 20151008a9. 2, 20151009a7. 2, 20151010b11. 2, 20151008b10. 2. how do I write mysql statements when I search for the percentage of the total number of times that the price

Similar to the comment function, Table 1 contains the floor, time, and text fields. It is best to have php code similar to the comment function to implement floor auto-increment and lock during insertion (to prevent high concurrency and same floor ).

My id is auto-incrementing and has a delete record. Now I want to find out the discontinuous IDs. My id is auto-incrementing and has a delete record. Now I want to find out the discontinuous IDs. Reply content: My id is auto-incrementing and has

Dear God, now I have a difficult problem that needs your help. There are two of the following tablesPost table: Article table.Record table: A table of records used to record the user's reading order. The record table records the primary key ID of

Please ask the hypothesis that I want to find a string of linked fields bits in MySQL Which function should I use? Like saying "Owogkwoeag Wegaweogkawoeg" "Owogkwwegawegoeag Wegaweogkawoeg" "Owogkwesseseryeag" Wegaweogkawoeg "I'm looking for 190. As

My id is self-increment, has deleted the record, now I want to find out the discontinuous ID. Reply content: My id is self-increment, has deleted the record, now I want to find out the discontinuous ID. Delete, it is best to add a field to

1. Server-level lock waitsThe thread ID of the wait lock can be seen through show processlist, but there is no way to know exactly which thread holds the lockCan be mysqladmin by debugThe associated thread waiting for the lock and who holds the lock

How to use locate and position functions in MySQL Find_in_set (Str,strlist)If the string str is in a string list strlist consisting of N substrings, the return value ranges from 1 to N. A list of strings is a string of self-chains that are

1. First check whether the profiling function is turned on like ' %pro% 'OrSELECT @ @profiling2. Open ProfilingSET Profiling=13. Execute SQL statementsFor example:SELECTTable_schema as 'Db Name', ROUND(SUM(Data_length+Index_length)/ 1024x768 / 102

Method One (stored procedure implementation):BeginDECLARE cnt INT DEFAULT 0;Select COUNT (*) into CNT from user;Set cnt = Round (cnt*0.9)-1;SELECT * from user limit CNT, 1;EndMethod two (direct query, only when the query permissions can be