1. Date Time function
Time Conversion second function: Time_to_sec
Mysql> Select Time_to_sec (' 01:01:01 ');+-------------------------+| Time_to_sec (' 01:01:01 ') |+-------------------------+| 3661 |+-------------------------+1 row in Set (0.00
CentOS6.7 using a non-root user (normal user) compile and install the MySQL database and implement the MySQL database service random auto-start using the Shell Script timed task mode1. About MySQL?MySQL is a relational database management system
1. download MySql
1. download MySql
Open http://www.mysql.com/downloads/mysql/#downloads download in browser
My downloaded version is Red Hat 5 version of http://www.mysql.com/downloads/mirror.php? Id = 407552
Upload the file to the server, or
Mysql inserts a random number into a field (inserts a random number to the MySQL database) and a random number to mysql
Common Code
UPDATE 'table name 'set' field name' = ceiling (rand () * 500000 + 500000) WHERE (condition );
Update 'table name'
Many of you know that you can use the rand () function to query data at random in mysql, but the rand () function can use hundreds of thousands of data records directly, if tens of thousands of data entries occur, let me introduce you to rand ()
MySQL functions and Usage examples
String functions
ASCII (str)Returns the ASCII value of the first character of the string 'str' (0 is returned when 'str' is an empty string)Mysql> select ASCII ('2 ');-> 50Mysql> select ASCII (2 );-> 50Mysql>
MySQL stored procedure SP explanation
1. Introduction to stored procedures
The commonly used Operating Database Language SQL statements must be compiled and then executed before execution. the Stored Procedure (Stored Procedure) is a set of SQL
Efficiency issues and solutions for random query of RAND () in mysql
Efficiency has always been a problem during our development, especially for a lot of large data operations. Today we have a random query of data, at the beginning, we may think of
String functionsASCII (str)Returns the ASCII value of the first character of the string str (str is empty when the string returns 0)Mysql> Select ASCII (' 2 ');50Mysql> Select ASCII (2);50Mysql> Select ASCII (' dete ');100ORD (str)If the string str
1. Introduction to stored procedures
The commonly used operating database language SQL statements must be compiled and then executed before execution. The Stored Procedure (Stored Procedure) is a set of SQL statements for specific functions, after
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