日期类型的列，并在其中插入值

Question

Hi I created a table in which one column is of date type and also works as PK . I tried to insert value 2009-01-07 into this column and had this error. Isn't Date default format yyyy-mm-dd ? I don't understand this.

Msg 241, Level 16, State 1, Line 3
Conversion failed when converting date and/or time from character string.

This is my query:

INSERT INTO Table_Name
Values ('2009-01-07', other column values)

Answer 1

Your value '2009-01-07' should be converted.

Date literals are always a deep source of troubles... Best was, to use either

• Unseparated: 20090107
• ODBC : {d'2009-01-07'}
• ISO8601 : 2009-01-07T00:00:00

But your format is short ISO 8601 and should work...

Some possible reasons:

• Other values in your VALUES list
• a trigger
• a constraint
• As a_horse_with_no_name stated in comment: Without a column list after INSERT INTO Table(col1, col2, ...) There is a great risk to state your values in a different order thus pairing values with the wrong columns...
• Invalid (but good looking ) dates such as 2016-06-31

Or a - well known - issue with SQL-Server. Sometimes the order of execution is absolutely not the way one expected it. There are several issues with conversion errors...

What you can try

• Use ODBC format (which is treated as DATETIME immediately)
• DECLARE a variable with this value and put it in place

Answer 2

Thank you all for the prompt replies. I read and tried all of them and found out why.

1. '2009-01-07' can be inserted into a Column with "Date" as data type if no CONSTRAINT has issue with that;
2. my problem was caused by a CHECK constraint on that column. Originally I set CONSTRAINT as Column_Name = 'Wednesday' After I modified it to DATEName(dw,[Column_Name]) = 'Wednesday' the inserting began to work.

Thanks again.