Oracle is a very popular relational database management system that supports a variety of date and time formats to meet various needs. Date format conversion is a very common operation when performing data processing, statistics and analysis. This article will introduce the relevant knowledge of Oracle date format conversion.
In Oracle, date data types include DATE and TIMESTAMP. The DATE type stores date and time information, accurate to the second level; the TIMESTAMP type can store more precise time information, with an accuracy as high as nanosecond level.
In Oracle, the date format consists of a series of format templates, using some predefined characters to represent different date and time elements. The following are some commonly used date format templates:
In Oracle, there are some date formatting functions that can Converts a date type to a string type, or converts a string type to a date type. The following are some commonly used date formatting functions:
The following are some examples:
In Oracle, there are also some date calculation functions that can add, subtract, compare and other operations on dates. The following are some commonly used date calculation functions:
Here are some examples:
The following are some examples of Oracle date format conversion:
SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH24:MI:SS') FROM DUAL;
The output result is: "2022-01-01 15:23:45"
SELECT TO_DATE('2022-01-01','YYYY-MM-DD ') FROM DUAL;
The output result is: "01-JAN-22"
SELECT (SYSDATE - TO_DATE('2022-01-01','YYYY-MM-DD'))*24 FROM DUAL;
The output result is: "340.544444444444444444444444444"
SELECT TRUNC(SYSDATE,'DD') FROM DUAL;
The output result is: "01-JAN-22"
SELECT ADD_MONTHS(SYSDATE,1) FROM DUAL;
The output result is: "01-FEB-22 "
This article introduces the knowledge related to Oracle date format conversion, including date data type, date format, date formatting function, date calculation function and related examples . Mastering this knowledge can make date-related data processing in Oracle database easier and more convenient.
The above is the detailed content of Detailed introduction to Oracle date format conversion. For more information, please follow other related articles on the PHP Chinese website!