Oracle retrieves data for a certain period of time

Oracle retrieves data for a certain period of time:

Sysdate + 1 is plus a day, sysdate +/-(1/48) is plus/minus half an hour

Select count (*) from table_name where table_name.date between to_char (sysdate-1/48, 'yyyymmdd HH: Mi') and sysdate

Date indicates the field name to be counted.

Table_name indicates the table name.

To_char is a date function to_char (sysdate, 'yyyymmdd HH: mi ') to intercept to minutes, and the corresponding to_char (sysdate, 'yyyymmdd hh') to intercept to hours. To_char (sysdate, 'yyyymm') is the month to which the object is intercepted,