问题
i have an assignment that i have to do in SQL Server Manager.
I have a database, and a table named User. Under user there are a column named e-mail.
The assignment is to create a new constraint to that table that affect the column e-mail.
There has to be only one '@' and minimum one '.'
It is not allowed to be any special characters such as ( !, ", #, ¤, %, etc.) <- this do not include the '@' and '.'
I've tried some different things but cant seem to make it work. Also it should be noticed that I am a beginner.
Thanks for your help
回答1:
Alternatively you can create your table with constraint, like this which will check if all the given conditions satisfies. Please change table data with your's
If table not Exist
CREATE TABLE Persons (
ID int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Email varchar(255),
CHECK (len(Email) - len(replace(Email,'@',''))=1 AND len(Email) -
len(replace(Email,'.',''))=1 AND CHARINDEX('!',Email)!>0 AND
CHARINDEX('#',Email)!>0 AND CHARINDEX('%',Email)!>0 AND
CHARINDEX('¤',Email)!>0 AND CHARINDEX('"',Email)!>0)
);
Some Rejected Inputs
some@some.!%#¤com
some@some.!%#com
some@some.%#com
some@some.#com
some@some@com
!some@some@com
etc...
Some Excepted Inputs
some@some.com
some222@some.com
harry_porter@some.com
332@some.com
etc....
If you have already a table then
GO
ALTER TABLE [dbo].[Yourtablename] WITH CHECK ADD Constraint EmailConstraint CHECK (((len([Email])-
len(replace([Email],'@','')))=(1) AND (len([Email])-
len(replace([Email],'.','')))=(1) AND charindex('!',[Email])<=(0) AND
charindex('#',[Email])<=(0) AND charindex('%',[Email])<=(0) AND
charindex('¤',[Email])<=(0) AND charindex('"',[Email])<=(0)))
GO
来源：https://stackoverflow.com/questions/46825083/sql-constraint-e-mail