Oracle obtains data for the current month of the current year.

In Oracle, we used whereto_char (t. t_created_tm,

Use where to_char (t. t_created_tm,

Oracle to get today's data, previously used to where to_char (t. t_created_tm, 'yyyy-MM-DD ') = to_char (SYSDATE, 'yyyy-MM-DD ');

This method is inefficient, and even if t. t_created_tm is indexed, the index cannot be used during query because it is compared after function encapsulation.

Here we will introduce how to use TRUNC (SYSDATE) = today to compare and filter data to get the results of today's data.

Select trunc (SYSDATE) from dual;
-- TRUNC (SYSDATE)

The following method is better.

SELECT * FROM TBL_STEP t where T.T _ CREATE_TM> = TRUNC (SYSDATE );

If the current year's data is retrieved

SELECT * FROM TBL_STEP t where T.T _ CREATE_TM> = TRUNC (SYSDATE, 'yyyy ');

Data for the current month

SELECT * FROM TBL_STEP t where T.T _ CREATE_TM> = TRUNC (SYSDATE, 'mm') AND T.T _ CREATE_TM <= LAST_DAY (SYSDATE)