MySQL database 8 - detailed explanation of the application of functions in the database

select current_date();//Get the current date, year, month, and dayselect current_time();//Get the current time, hours, minutes, and secondsselect current_timestamp();//Get the current year, month, day, hours, minutes, and secondsselect date('2017-10-28');//Get the parameter dateselect date_add('2017-10-28', interval 10 day);//Add the specified year/month/day to the parameter dateselect date_sub('2017-10-28', interval 10 day);//Subtract the specified year/month/day from the parameter dateselect datediff('2017-10-10', '2016-9-1');//Calculate the number of days between two dates

 //user() queries the current userselect user();
 
 //md5(str) performs md5 digest on a string and obtains a 32-bit string after digest select md5('admin')
 
 //database() displays the database currently in use select database();

 //password() function, MySQL database uses this function to encrypt users select password('root');
 
 //ifnull（val1， val2） If val1 is null, return val2, otherwise return the value of val1 select ifnull('abc', '123'); // abc is not null, so return abc