DATE_FORMAT - Realtime Compute for Apache Flink - Alibaba Cloud Documentation Center

This topic describes how to use the DATE_FORMAT function. This function converts a date value of the STRING type from a format into a specific format.

Limits

This function is supported only in Realtime Compute for Apache Flink that uses Ververica Runtime (VVR) 3.0.0 or later.

Syntax

VARCHAR DATE_FORMAT(TIMESTAMP time, VARCHAR to_format)
VARCHAR DATE_FORMAT(VARCHAR date, VARCHAR to_format)
VARCHAR DATE_FORMAT(VARCHAR date, VARCHAR from_format, VARCHAR to_format)

Input parameters


Parameter	Data type	Description
time	TIMESTAMP	The source string.
date	VARCHAR	The source string. The default format is yyyy-MM-dd HH:mm:ss.
from_format	VARCHAR	The original format. This parameter is optional. The default format is yyyy-MM-dd hh:mm:ss.
to_format	VARCHAR	The format of the output date.

Note If an input parameter is NULL or a parsing error occurs, NULL is returned.

Example

Test data


date1(VARCHAR)	datetime1(VARCHAR)	nullstr(VARCHAR)
0915-2017	2017-09-15 00:00:00	NULL

Test statement

SELECT DATE_FORMAT(datetime1, 'yyMMdd') as var1,
 DATE_FORMAT(nullstr, 'yyMMdd') as var2,
 DATE_FORMAT(datetime1, nullstr) as var3,
 DATE_FORMAT(date1, 'MMdd-yyyy', nullstr) as var4,
 DATE_FORMAT(date1, 'MMdd-yyyy', 'yyyyMMdd') as var5,
 DATE_FORMAT(TIMESTAMP '2017-09-15 23:00:00', 'yyMMdd') as var6
FROM T1;

Test result


var1(VARCHAR)	var2(VARCHAR)	var3(VARCHAR)	var4(VARCHAR)	var5(VARCHAR)	var6(VARCHAR)
170915	null	null	null	20170915	170915