I have an tomcat application page that stores data from a form to a mysql
datasource running on the server. Many of the form fields are simple text
fields where the user can leave the field blank when filling out the form.
The parameter values from the form are passed to the preceding jsp page that
executes the <sql:update dataSource="${my_db_data}"> using the Java Standard
Tag Library. I'll past below a snippet from the code:
<sql:update dataSource="${my_db_data}">
INSERT INTO my_database_table
(firstname, middlename, lastname, suffix, email_address.... and on it goes
listing fields from the database)
VALUES (?, ?, ?, ?....... and on it goes listing ? marks equal tothe
number of values above)
<sql:param value="${param.firstName}" />
<sql:param value="${param.middleName}" />
<sql:param value="${param.lastName}" />
<sql:param value="${param.suffix}" />
<sql:param value="${param.emailAddress}" />
The problem I have is: if the user left a field blank on the form, say the
email_address, the value that gets passed to the database is a blank ('')
field value. However, I want the email_address field to have a UNIQUE Index
within the database and that is not possible if there are multiple records
with blank ('') field values for the email_address because MySQL counts such
values as tangible capable of enforcing the index on... unlike how it would
ignore email address that had the value of NULL.
I need the emailAddress field to store as NULL instead of a blank ('') field
in order to have the UNIQUE Index in the MySQL db. With the implementation
as it is above, the field doesn't save as NULL. How do I get it to?
just ferindo
