on duplicate entry add name if empty php mysql - php

Question

Clarification of what I'm trying to accomplish:
Update "user name", if there is a record with the same e-mail but no name. if user already has a name, then don't make any changes
I have a website where all users can be "subscribers, entrepreneurs or investors". If a subscriber (of whom I have previously only asked for email) chooses to upload a business idea then that person will probably use the same e-mail address as before only this time adding a name. So I'd like to INSERT INTO, and if e-mail already exists - add the name, but only if there is not a name there already (so that a person cannot simply over write somebody else's details).
I've gotten this far:
mysql_query("
INSERT INTO users
(email, name)
VALUES
('" .$epost. "', '" .$namn. "')
ON DUPLICATE KEY UPDATE
name=VALUES(name) -->[if name == '', else do nothing...]
");
Now it replaces the current name with a new one if different.
I searched "on duplicate update if field empty"
and found:
http://forums.aspfree.com/sql-development-6/on-duplicate-key-update-but-only-if-value-isn-t-482012.html (merging?)
conditional on duplicate key update (closer, but I don't want to update it if it differs, only if the field is empty.)
http://bytes.com/topic/php/answers/914328-duplicate-key-update-only-null-values (if the input is blank.. well it's not)
http://boardreader.com/thread/Insert_on_duplicate_key_update_only_if_c_can8Xachr.html (the layout of this page got me lost)
http://www.digimantra.com/tutorials/insert-update-single-mysql-query-duplicate-key/ (it simply updates)
I believe this might be kind of what I'm after (?) http://thewebfellas.com/blog/2010/1/18/conditional-duplicate-key-updates-with-mysql but I haven't managed to make it work
This code:
mysql_query("UPDATE users SET name='".$namn."'
WHERE email='".$epost."' AND name =''");
updates the name, only if it's previously null, and that's what I'm after however it does not insert a new record if email doesn't already exist.
My table
So I tried this:
mysql_query("
INSERT INTO users
SELECT email, 'victoria' FROM users
WHERE email='victoria#hejsan.se' ON DUPLICATE KEY UPDATE name = 'victoria'
");
and I tried this:
mysql_query("
INSERT INTO users
SELECT email, 'yay' from users
WHERE email='victoria#hejsan.se'
ON DUPLICATE KEY
UPDATE name = values(name)
");
from #Fluffeh 's answer
but nothing happens. Did i misinterpret the answer?
It just hit me that if someone already has an account then they should also have a password already, and so I'll just ask them to verify their password, and make sure I do an AJAX call while they insert their e-mail to see if the e-mail is already registered :) And so then this is no longer an issue, and I think that is the solution I'll go with. !)

Answer 1

The only way that you could use the insert .... on duplicate key... syntax to solve your issue would be if name and email made a composite key - and I think you would be better off using an auto_increment as a primary key.
You might have to put a little logic into the PHP to do a check first, then insert or update - or write a function to do that same test for you - but neither will be a simply query that you can just fire off.
Edit: Not sure if this is what you want to do, but I think that the best solution for your requirements is to actually use two tables in a one to many relationship.
Table-Users
id | email | name
create table users(
id int(10) not null auto_increment,
email varchar(100),
name varchar(100),
primary key(email, name)
);
Table-Ideas
id | userID | idea
create table users(
id int(10) not null auto_increment primary key,
userID int(10) not null,
idea text
);
With the primary key on the table, you can safetly do an insert... duplicate... without worrying about over-writing folks. The second table will however allow you to have the ideas stored safetly locked to the user, and let you have a number of ideas per user. As the relationship is the users.id to ideas.userID you won't lose who owns it even if their details are updated.
Edit: (aka, ZOMG facepalm)
$query="
update users
set name='".$userName."'
where
email='".$userEmail."'
and name is null";
Edit 2: (aka, wipes brow)
insert into users
select email, '".$namn."' from users where email='".$epost."'
on duplicate key
update name = values (name);
and here it is working:
mysql> create table test1 (myName varchar(10) unique, myEmail varchar(10));
Query OK, 0 rows affected (0.02 sec)
mysql> insert into test1 values ('Tom','something');
Query OK, 1 row affected (0.01 sec)
mysql> insert into test1 values('Nick',null);
Query OK, 1 row affected (0.00 sec)
mysql> select * from test1;
+--------+-----------+
| myName | myEmail |
+--------+-----------+
| Tom | something |
| Nick | NULL |
+--------+-----------+
2 rows in set (0.00 sec)
mysql> insert into test1 select myName, myEmail from test1
where myName='Tom' on duplicate key update myEmail = values (myEmail);
Query OK, 0 rows affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+--------+-----------+
| myName | myEmail |
+--------+-----------+
| Tom | something |
| Nick | NULL |
+--------+-----------+
2 rows in set (0.00 sec)
mysql> insert into test1 select 'Tom', myEmail from test1
where myName='Tom' on duplicate key update myEmail = values (myEmail);
Query OK, 0 rows affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+--------+-----------+
| myName | myEmail |
+--------+-----------+
| Tom | something |
| Nick | NULL |
+--------+-----------+
2 rows in set (0.00 sec)
mysql> insert into test1 select myName, 'Something Else' from test1
where myName='Tom' on duplicate key update myEmail = values (myEmail);
Query OK, 2 rows affected, 1 warning (0.01 sec)
Records: 1 Duplicates: 1 Warnings: 1
mysql> select * from test1;
+--------+------------+
| myName | myEmail |
+--------+------------+
| Tom | Something |
| Nick | NULL |
+--------+------------+
2 rows in set (0.00 sec)
mysql> insert into test1 select myName, null from test1
where myName='Nick' on duplicate key update myEmail = values (myEmail);
Query OK, 0 rows affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+--------+------------+
| myName | myEmail |
+--------+------------+
| Tom | Something |
| Nick | NULL |
+--------+------------+
2 rows in set (0.00 sec)
mysql> insert into test1 select myName, 'yay' from test1
where myName='Nick' on duplicate key update myEmail = values (myEmail);
Query OK, 2 rows affected (0.01 sec)
Records: 1 Duplicates: 1 Warnings: 0
mysql> select * from test1;
+--------+------------+
| myName | myEmail |
+--------+------------+
| Tom | Something |
| Nick | yay |
+--------+------------+
2 rows in set (0.00 sec)
Edit 3: Try this for your $query
insert into table1 select coalesce(email,'".$epost."') as email, coalesce(name,'".$namn."') as name from table1
where email='".$epost."' on duplicate key update name = values (name);

Answer 2

If you want to update a field that is already exist, you can do this as;
-- MySQL Reference
INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6)
ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);
-- so your code
INSERT INTO users
(email, name)
VALUES
('" .$epost. "', '" .$namn. "')
ON DUPLICATE KEY UPDATE email=VALUES(email), name=VALUES(name)
http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html
UPDATE
At this point, you need "MySQL conditional insert". Let's try it;
CREATE TABLE IF NOT EXISTS `users` (
`name` varchar(50) NOT NULL,
`email` varchar(255) NOT NULL,
UNIQUE KEY `email` (`email`)
)
INSERT INTO users (name, email) VALUES('kerem', 'qeremy[atta]gmail[dotta]com');
INSERT INTO users (name, email) VALUES('test', 'test#example.com');
>> 2 rows inserted. ( Query took 0.0005 sec )
-- this is your part (regarding email field is UNIQUE, so WHERE email='search email')
INSERT INTO users (name, email)
SELECT 'test', 'test#example.com' FROM DUAL WHERE NOT EXISTS (
SELECT * FROM users WHERE email = 'test#example.com' LIMIT 1
);
>> 0 rows inserted. ( Query took 0.0003 sec )
https://www.google.com/search?q=conditional+insert+mysql
http://allurcode.com/2011/04/15/mysql-conditional-insert/ (which is useful search result)
UPDATE 2
If this does not work for you, then you can do your work like (just an input);
mysql_query("INSERT IGNORE INTO users (name, email) VALUES('$name', '$email')");
if (!mysql_insert_id()) {
mysql_query("UPDATE users SET name='$name' WHERE name='' AND email='$email'");
}
Or;
mysql_query("UPDATE users SET name='$name' WHERE name='' AND email='$email'");
if (mysql_affected_rows() < 1) {
mysql_query("INSERT INTO users (name, email) VALUES('$name', '$email')");
}

Answer 3

I'd like to suggest this solution using the control function IFNULL(exp1,exp2), defined as "if exp1 is not null, returns exp1; if exp1 is null, returns exp2".
http://dev.mysql.com/doc/refman/5.7/en/control-flow-functions.html
INSERT INTO users (name, email) VALUES ('$name','$email')
ON DUPLICATE KEY UPDATE name = IFNULL(name, VALUES(name))
Of course you must be beyond this somehow, but it helped me.