1 , the current date, time now () to get the current date and time // 2019 - 11 - 12 18 : 18 : 57 CURDATE () the current date, /// 2019 - 11 - 12 curtime () the current time // 18 : 18 : 57 is CURRENT_TIME (); // with curtime (), CURRENT_TIME CURRENT_DATE (); // with CURDATE (), CURRENT_DATE CURRENT_TIMESTAMP () // with now () 2 , the time taken: DATE (expr) //If the resolution fails to return Null, return date type DATE Time (expr) // return time type Time year (expr) // Returns the month The (expr) // Returns [ 1 - 12 ] Day (expr) // Returns [ . 1 - 31 is ] hour (expr) // returns the number [ 0 - 23 is ] minute (expr) // returns the number [ 0 - 59 ] LAST_DAY (date) // return the last day, the date type return // 2018 - 04 - 30 to_days (expr)// return 0 to January 1 of the year the total number of days in the DATE_FORMAT (expr, pattern) // time interception returns the string expr: time string, date string or date time type. For the interception of the year, month, day, hour, minute, second string is returned correspondence, because the date and time type mysql itself provides only DATE, Time, datetime , timestamp , year five types 3 , by date and time Save ADDDATE (date, iNTERVAL expr unit) returns the date format date time date to be operated, the date may be the date string type iNTERVAL: MySQL keyword, meaning the interval, gap means operating unit, year, month, day , hours, minutes, seconds corresponds YEAR, MONTH , DAY , HOUR, MINUTE, sECOND, expr want to increase or decrease the time unit. expr > 0 , increases, expr < 0 reduction SUBDATE (date, INTERVAL expr unit) similar ADDDATE () . 4 the difference between the two dates DATEDIFF(date1, DATE2) // difference between the two dates 5 , the date string is converted to the DATE_FORMAT (DATE, ' % Y-M-% D%% H:% I:% S ' ) // Switch characters string TIME_FORMAT (dATE, pattern) // only conversion time, conversion date not FROM_UNIXTIME ( timestamp , pattern) // time stamp to a string 6 , the string transfer time STR_TO_DATE (dateStr, pattern) dateStr: string date expression pattern: pattern matching 7 , the time stamp conversion UNIX_TIMESTAMP ( [ dATE ] ) into the date stamp, the default parameters can not write now () dATE datetime type may be time string may be ' 2018 - 2 - 12 is ' FROM_UNIXTIME ( timestamp , ' % Y-M-% D%% H:% I:% S ' ) formatted according to the format timestamp timestamp : timestamp i.e. UNIX_TIMESTAMP () mode pattern of the target string. Results returned when using the format parameter *** string *** . Typical times more formatting parameters as placeholders refer to, % the Y years, four digits % Y years, the last two digits % m month, numbers [ 1-12 ] % D day, day of the month in the , two numbers [ 1-31 ] % H hours, 24 ary [ 0-23 ] % H hours, 12 ary [ 0-11 ] % I min [ 0-59 ] % S| % S second 0 - 59