SQL 服务器将 Varchar 转换为 Datetime 并找到最大值

Question

I try to find max date from a DATE column, the column format is YYYY-MM and its of type varchar .

DATE
--------
2020-07     (I try to find this value)
2020-06 
2020-05
2020-04

I tried with the following SQL code:

SELECT 
    CONVERT(datetime, 'DATE') AS Date 
FROM
    DateTable

Answer 1

You can try the below way -

select max(cast(concat(columnName,'-01') as date))
from yourtable

Answer 2

Try

select Top 1 Column_Name from table_Name order by Column_Name desc
*//here replace Column_Name by column that contains dates*

Answer 3

What about

select left(convert(varchar,max(concat([date],'-01'))),7) maxDate
from DateTable