尝试将存储为日期时间的nvarchar转换为int

Question

I have a SQL date field that is stored as nvarchar(max) .

Example: 4/7/2016 12:50:03 AM

I need to convert this to int .

I have this: cast(convert(char(8), DateField,112) as int)

but I'm getting an error message

Conversion failed when converting the varchar value '5/22/201' to data type int

Obviously, / isn't an int character. Any suggestions??

Answer 1

我相信如果将varchar强制转换为某个日期，它将可以正常工作（convert（char（8），cast（DateField as datetime），112）为int）

Answer 2

您可以replace斜杠replace为空格：

CAST(REPLACE(CONVERT(char(8),DateField,112),'/','') as int)

Answer 3

First, you should convert it to DATETIME , then convert that to INT . And don't count on the date portion being any particular length -- depending on the month and day of month, it can be from 8 to 10 chars long.

DECLARE @T TABLE (datefield VARCHAR(MAX))
INSERT @T VALUES ('4/7/2016 12:50:03 AM')
SELECT CAST(CONVERT(DATETIME, DateField) AS INT) FROM @T

Answer 4

I think you need a chain of conversions: string --> datetime --> string --> int

cast(convert(char(8), convert(datetime, DateField, 101), 112) as int)

You might be able to rely on implicit conversions along the chain, but I prefer being explicit.