禁止在列上设置空值，并在getdate()列上设置默认值

/*Deal with any existing NULLs*/
UPDATE YourTable SET created_date=GETDATE() /*Or some sentinel value 
                                                '19000101' maybe?*/
WHERE created_date IS NULL


/*Disallow NULLs*/
ALTER TABLE YourTable ALTER COLUMN created_date DATE NOT NULL

/*Add default constraint*/
ALTER TABLE YourTable ADD CONSTRAINT
    DF_YourTable_created_date DEFAULT GETDATE() FOR created_date

修改现有表中的现有列:

ALTER TABLE YourTable ADD CONSTRAINT DF_YourTable DEFAULT GETDATE() FOR YourColumn

创建新表时的语法是:

CREATE TABLE MyTable
(
    MYTableID INT IDENTITY(1,1),

    CreateDate DATETIME NOT NULL CONSTRAINT DF_MyTable_CreateDate_GETDATE DEFAULT GETDATE()
)

在SQLPlus中，当创建一个表时，它就像as

SQL>创建表Test

 ( Test_ID number not null,
   Test_Date date default sysdate not null );

SQL> insert into Test(id) values (1);

 Test_ID Test_Date
       1 08-MAR-19

这对我很有用……

ALTER TABLE [accounts] 
 ADD [user_registered] DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ;

这也是可行的:

CREATE TABLE Example(
...
created datetime default GETDATE()
);

Or:

ALTER TABLE EXAMPLE ADD created datetime default GETDATE();