使用VARCHAR列的一部分作为where子句中的日期

Question

I have a table where the varchar column CREATED_BY has the data in the format
USER - dd/MM/yyyy hh:mm .

I'm trying to do data migration and need to get records where the created date is greater than a certain date, but the format of the column makes this difficult, so

SELECT * FROM TABLE_NAME WHERE -- last part of CREATED_BY > SOMEDATE

Answer 1

Well, since the dd/MM/yyyy hh:mm format has a fixed length, you can use the RIGHT function to extract the data part from your string:

SELECT * 
FROM TABLE_NAME 
WHERE CONVERT(datetime, RIGHT(CREATED_BY, 16), 103) > somedate 

Answer 2

您需要从字符串中提取日期：

WHERE cast(reverse ( substring ( reverse ( @string  ) , 1 , 16 ) )  as datetime) > somedate