插入之前，Microsoft SQL Server转换中的存储过程

Question

I am trying to create a stored procedure that does manipulation of parameter passed in before inserting it into my table. One of the columns in my table is called DATE_CHANGED and basically what I gg to do here is to change a passed date parameter like December 1st 2017 to 20171201. This is an int value.

I wrote a stored procedure like this:

CREATE PROCEDURE date_generate
     @startDate DATE
AS
BEGIN
    DECLARE @DATE_KEY INT

    @DATE_KEY = CONVERT(INT, FORMAT(@startDate, 'YYYYMMDD')

    INSERT INTO table date_key = @DATE_KEY
END

However I get an error

Incorrect syntax near '@DATE_KEY

Are local variable declared only used for SQL query statement like

select * 
from table 
where date_key = @DATE_Key?

Answer 1

There is more than one error.

• Use SET to assign values to a variable.
• Have a look at INSERT statement too.

CREATE PROCEDURE date_generate
    @startDate date
    AS
    BEGIN
        DECLARE @DATE_KEY int;
        SET @DATE_KEY = CONVERT(int, format(@startDate, 'YYYYMMDD'));
        INSERT INTO DATE_CHANGED (date_key) 
        VALUES (@DATE_KEY);
    END

Answer 2

This seems really strange. You don't even need a local variable. Based on your code, you could write:

create procedure date_generate (
    @startDate date
) as
begin
    insert into table (date_key)
        values ( convert(int, format(@startDate, 'YYYYMMDD')) );
end;  -- date_generate

Or, I might write:

create procedure date_generate (
    @startDate date
) as
begin
    insert into table (date_key)
        values ( year(@startDate) * 10000 + month(@startDate) * 100 + day(@startDate) );
end;

Why you would have a table with a single date on each row doesn't really make sense to me. Why you would be storing that "date" as an integer also doesn't make sense.

Answer 3

As far as I've understood, your stored procedure accepts a DATE as a parameter, but you need to do an INSERT with an INT.

You can easily convert a DATE to a VARCHAR and then to a INT, this way:

DECLARE @DateASInt INT = CAST(CONVERT(VARCHAR(8), @startDate, 112) AS INT);

So, your stored procedure will be like this:

CREATE PROCEDURE date_generate
    @startDate date
    AS
    BEGIN
        INSERT INTO date_key
            VALUES (CAST(CONVERT(VARCHAR(8), @startDate, 112) AS INT));
    END