validation on email / postcode fields in sql/oracle

问题

Would be gratefull for some advice on the following - Is it possible to validate email and postcode fields through some kind of check constraint in the sql in oracle ? or this kind of thing as i suspect pl/sql with regular expressions ?

Thanks

回答1:

If you're only concerned with the US, there are several sources of zip codes that you can obtain in flat-file format and import into a table, and then apply a foreign key constraint in your addresses to that table.

Email addresses can be matched against a regular expression (needs 10g or higher) to validate the format, but checking to see if they are actual addresses is a much more difficult task.

回答2:

Here's the regexp syntax for an email address, including quotes

'[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]{2,4}'

So you can use regexp_like() in a where clause or regexp_substr() to check whether your field contains a valid email address. Here's an example-you'll see that the regexp_substr() returns NULL on the address missing the .domain, which fails the substring validation. From there you can build a check constraint around it, or enforce it using a trigger(yuck), etc.

SQL> desc email
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 EMAIL_ID                                           NUMBER
 EMAIL_ADDRESS                                      VARCHAR2(128)


SQL> select * from email;

  EMAIL_ID EMAIL_ADDRESS
---------- ----------------------------------------
         1 NEIL@GMAIL.COM
         2 JOE@UTAH.GOV
         3 lower_name@lower.org
         4 bad_address@missing_domaindotorg


SQL> @qry2
SQL> column email_address format a40
SQL> column substr_result format a30
SQL> SELECT  email_address
  2       ,  regexp_substr(email_address,'[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]{2,4}') substr_result
  3    FROM  email
  4  /

EMAIL_ADDRESS                            SUBSTR_RESULT
---------------------------------------- ------------------------------
NEIL@GMAIL.COM                           NEIL@GMAIL.COM
JOE@UTAH.GOV                             JOE@UTAH.GOV
lower_name@lower.org                     lower_name@lower.org
bad_address@missing_domaindotorg

Using the same data, here is a query which limits only valid email addresses, using REGEXP_LIKE

SQL> column email_address format a40
SQL> column substr_result format a30
SQL> SELECT  email_address
  2    FROM  email
  3   WHERE  REGEXP_LIKE (email_address, '[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]{2,4}');

EMAIL_ADDRESS
----------------------------------------
NEIL@GMAIL.COM
JOE@UTAH.GOV
lower_name@lower.org

Search the contents page of the SQL Reference for regexp to see the regular expression support.

回答3:

an even better regular expression is:

^[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]{2,4}$

(same expression given but anchored to start (^) and end ($) of line)

without the anchors, expressions like 'test1@hotmail.com some other text' would be validated and, if you are trying to validate one email, the above string should not validate

Note: the email should be previously trimmed so that leading or trailing spaces won't screw up validation.

Hope it helps,

回答4:

Be careful at the '.' character: this is a joker (like * or % in SQL syntax). You must excape it with '\'.

Here is the regexp I use to match RFC2822 (maybe not all cases :)):

'^[a-zA-Z0-9!#$%''\*\+-/=\?^_`\{|\}~]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]{2,4}$'

回答5:

declare

-- where customer is the table in my case

email_input customer.email%type;

begin

    email_input:=:EMAIL; 
    IF email_input is not null
    AND email_input not like '%@%.COM' then
        message('Please enter a valid email address!');
        message('   ');
        clear_message;
        :EMAIL:=null;
        raise form_trigger_failure;
    end if;
end;

来源：https://stackoverflow.com/questions/787167/validation-on-email-postcode-fields-in-sql-oracle

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