如何从C＃比较SQL Server日期时间

Question

I've got to make a query from C# and compare with a datetime . Datetime is stored in my database like this:

2014-11-09 00:00:01

and I'm using this query:

SELECT * 
FROM Table 
WHERE DATETIMEVAR = '19/11/2014 0:00:01' AND OTHERVAR = 1

But it's not in the same format. Is there a way to convert from System.DateTime in C# to dates in SQL Server, or a way to cast from SQL Server the datetime in that format?? Should I check with like instead of = in Where clause.

Thanks.

Answer 1

The best way would be to have a parametrized query in C#, and then set your date time parameter as a datetime (instead of relying on converting dates back and forth to and from strings).

So you should have something like:

SELECT * 
FROM Table 
WHERE DATETIMEVAR = @DateTimeValue AND OTHERVAR = 1

and then define that @DateTimeValue parameter as datetime and set it as datetime

That approach:

• prevents any SQL injection vulnerability
• avoid any string/formatting issues - it compares a DATETIME to a System.DateTime in their native format

Answer 2

如果要从DateTime对象生成查询，只需执行date.ToString("yyyy-MM-dd HH:mm:ss")即可在查询中将其转换为该格式。