是否使用SQL将datetime列可移植地转换为字符串？

Question

I have a column defined as a datetime in sybase and have converted it to a string using

ISNULL(CAST(CAST(most_recent_trades.asof_date AS DATE) AS VARCHAR(20))

It turns out that the representation of this as a string in sybase differs from my unit test db which is H2.

In sybase
Sep  1 2016

In H2
2016-09-01

The column is defined as datetime in H2 as well.

Is there a way to convert the datetime column to a string that is the same string representation in both Sybase and H2 (I don't need the time portion of this if that helps any)?

EDIT : I don't think there is any way to do this in a portable way with one function, so what I decided to do was use the YEAR, MONTH and DAY functions (they are all available in Sybase and H2), extract the parts and concatenate them to make a date that will look the same when represented as a string in both Sybase and H2. This works for me at this point.

Answer 1

我将使用CONVERT（）函数的格式121 ，然后获取它的日期部分，如下所示：

substring(convert(varchar(30), most_recent_trades.asof_date, 121), 1, 10)