How can I check in MYSQL PHP if two columns are unique then not insert again, else if just one column is unique then insert, is that even possible to do in php?
EDIT:
Lets say I have a table like this,
userId | codeId
And I I send a query like this,
$query = $pdo->prepare('insert into table (userId, codeId) values (?,?)');
So now I want to check if userId and codeId are added already once do not insert again, and if just one is added, then do insert the entire query,
I hope its more understanding.
Set up a unique key for those columns, then the mysql query will FAIL when you try to insert.
Use REPLACE INTO instead of INSERT INTO ... ?
Do something like the code below (where TEXT_ID and TEXT_CATEGORY, are keys of table):
INSERT INTO
table_texts
SET
text_id = 174,
text_category = "pam_texto"
ON DUPLICATE KEY UPDATE
text_id = 174,
text_category = "pam_texto";
The above code tries to insert, but if the keys are duplicated performs an update on the line.
Related
I've been doing some research and haven't found anything that I've been able to make work, unfortunately, and I think that stems from not understanding the MySQL construct in the examples I've been looking at.
What I'm trying to do is run an insert query, and do a check on values in 3 specific columns to ensure they don't exist, then insert, else do nothing.
My Table is pretty basic: id(int11), user(varchar(45)), label(varchar(255)), agent(varchar(255)), empid(varchar(10)).
My id is my Primary, with Auto increment, and here is my code I currently have that works on inserting, but doesn't have the handling in place for duplicates:
$i = 0;
foreach ($agents as $ag){
$sql = mysql_query("INSERT INTO `pms_users`
(`id`,`user`,`label`,`agent`,`empid`)
VALUES
(NULL, '$user','$group','$labels[$i]','$ag')");
$i ++;
}
The three columns I need to check against are the $user, $group, and $ag.
Add a unique index for (user, label, empid). Then the database won't allow you to create duplicates.
ALTER TABLE pms_users
ADD UNIQUE INDEX (user, label, empid);
If you can only have one row per combination of user, label and agent, you should define them as a unique constraint:
ALTER TABLE pms_users ADD CONSTRAINT pms_users_unq UNIQUE (`user`, `label`, `agent`);
And then let the database do the heavy lifting with an insert-ignore statement:
INSERT IGNORE INTO `pms_users`
(`user`, `label`, `agent`, `empid`)
VALUES ('some_user', 'some_label', 'some_agent', 123)
You can try insert on duplicate key update query.. It checks duplicate keys. If they exist MySQL do update query if not exist MySQL doing insert query.
Sure in your database you should declare unique keys.
Here is MySQL documentation for this case
https://dev.mysql.com/doc/refman/8.0/en/insert-on-duplicate.html
I have two columns into mysql table map 1. First column have name json, second have name user_id
Now, I need to insert data to new row if user_id does not exist into mysql table, but if excist I need just to update json column where user_id = user_id ...
I try:
try {
$STH = $db->prepare("INSERT INTO map (user_id, json)
VALUES (:2,:1)
on duplicate key update json=values(json)");
$STH->bindParam(':1', $_POST['mapData']);
$STH->bindParam(':2', $user_id);
Some ideas? I use php pdo.
How to solve this problem?
Thanks!
You miss : in on duplicate key update json=values(:json)");, so try like this:
try {
$STH = $db->prepare("INSERT INTO map (user_id, json)
VALUES (:user_id,:json)
on duplicate key update json=values(:json)");
$STH->bindParam(':json', $_POST['mapData']);
$STH->bindParam(':user_id', $user_id);
Besides, your question is related to:
Here
Just have a look at MySQLs REPLACE command.
Cite from MySQL manual:
REPLACE works exactly like INSERT, except that if an old row in the
table has the same value as a new row for a PRIMARY KEY or a UNIQUE
index, the old row is deleted before the new row is inserted.
That could be the solution to your problem. Otherwise, make a select, if the id exists, make an update, otherwise an insert.
Is my code/syntax wrong? I'm not sure what is wrong and am new to this. I have created a table in PHPMyAdmin. It has two columns. One is "id" and is the primary key/auto-increment. The other column is "steamname".
This code is supposed to take a person's online name and enter it into the database. If there is already a record, it should update it anyways with the same/latest name.
The name of the table in phpmyAdmin is names
<?php
// Capture person's name from XML file
$profile = simplexml_load_file('UrlGoesHere.Com/?xml=1', 'SimpleXMLElement', LIBXML_NOCDATA);
echo (string)$profile->steamID;
//Enter name into databse and overwrite it if same/duplicate
$con=mysqli_connect("localhost","username","password","databaseName");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// Perform queries
mysqli_query($con,"INSERT INTO names (steamname) VALUES ('$profile') ON DUPLICATE KEY UPDATE steamname = VALUES('$profile')");
mysqli_close($con);
?>
I tested this by manually changing the value of a row in "steamname" within PHPMyAdmin to "woogy" and then running this script to see if it would update that database value... nothing is happening. It should update "woogy" to the proper name.
-----------Updates---------------
Hi all. Thank you for the input. I now have my code as follows. Sorry if it's still wrong. I'm learning.
<?php
$profile = simplexml_load_file('http://steamcommunity.com/profiles/76561198006938281/?xml=1', 'SimpleXMLElement', LIBXML_NOCDATA);
echo (string)$profile->steamID;
$con=mysqli_connect("localhost","userHere","passwordHERE","DBName");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// Perform queries
mysqli_query($con,"INSERT INTO names (steamname) VALUES ('$profile') ON DUPLICATE KEY UPDATE ID = LAST_INSERT_ID(ID), steamname = VALUES(steamname)");
mysqli_close($con);
?>
This is how the database looks before running the script: (woogy should change to Chatyak)
Click image here
Now, when I run the PHP page, this is what happens to my database.
How database looks after running script
Not sure why it didn't update - and also why there is such a huge space?
Right syntax of INSERT ... ON DUPLICATE KEY would be like below, you need to mention the column name in VALUES like VALUES(column_name) instead of VALUES('$profile'). Also, you are missing the PK column ID in case of UPDATE. Cause you want to update the steamname for particular ID value.
INSERT INTO names (steamname)
VALUES ('$profile')
ON DUPLICATE KEY UPDATE ID = LAST_INSERT_ID(ID), steamname = VALUES(steamname)
(OR)
INSERT INTO names (steamname)
VALUES ('$profile')
ON DUPLICATE KEY UPDATE steamname = VALUES(steamname)
Quoted from MySQL documentation
If a table contains an AUTO_INCREMENT column and INSERT ... UPDATE
inserts a row, the LAST_INSERT_ID() function returns the
AUTO_INCREMENT value. If the statement updates a row instead,
LAST_INSERT_ID() is not meaningful. However, you can work around this
by using LAST_INSERT_ID(expr).
You can't use INSERT ON DUPLICATE KEY UPDATE (IODKU) to update instead of inserting a new row unless you try to insert a value that conflicts with an existing primary or unique key column.
Since you're not specifying any value for ID in this INSERT, it will always increment the auto-increment primary key and insert a new row.
If you want the INSERT to replace the steamname for an existing row, you must specify the ID value in your INSERT.
Re your first comment:
I looked at your samples. It's not surprising that it created a new row. It generated a new auto-increment ID value because you didn't specify an ID in your INSERT. So it naturally created a new row. It has no way of telling which row you are trying to replace.
Here's a demo:
mysql> create table names (id serial primary key, steamname text);
mysql> insert into names (steamname) values ('Woogy')
on duplicate key update ID = LAST_INSERT_ID(ID), steamname = VALUES(steamname);
Ignore the ID = LAST_INSERT_ID(ID) part, this has no effect. It's a no-op. #Rahul suggested it, but unfortunately he or she is mistaken. I'm going to take out that term in subsequent tests.
So what happens in this INSERT? You specify a value for steamname, but no value for ID. So MySQL generates a new value for ID. That becomes the primary key value for a new row, and that row is inserted with the steamname 'Woogy'.
mysql> select * from names;
+----+-----------+
| id | steamname |
+----+-----------+
| 1 | Woogy |
+----+-----------+
Next we try to change the name to 'Chatyak':
mysql> insert into names (steamname) values ('Chatyak')
on duplicate key update steamname = VALUES(steamname);
Which row does this apply the change to? The INSERT does not specify an ID value, so MySQL auto-increments another new ID value. That value is the primary key for a new row, and that's the row that gets the steamname 'Chatyak'.
mysql> select * from names;
+----+-----------+
| id | steamname |
+----+-----------+
| 1 | Woogy |
| 2 | Chatyak |
+----+-----------+
What this means is that you can never trigger the ON DUPLICATE KEY part if you let the auto-increment generate a new ID value every time you INSERT. Every INSERT will result in a new row.
As I said above, ON DUPLICATE KEY does nothing unless you try to insert a value that conflicts with a primary or unique key for a row that already exists in the table. But in this case you aren't conflicting, you're always generating a new ID value. So it inserts a new row.
If you had a UNIQUE KEY constraint on steamname, then that would be another opportunity for triggering ON DUPLICATE KEY. But it still won't do what you want.
mysql> alter table names add unique key (steamname(20));
Then if you try to insert the same steamname as one that already exists, it will not insert a new row. It'll update the existing row.
mysql> insert into names (steamname) values ('Chatyak')
on duplicate key update ID = LAST_INSERT_ID(ID), steamname = VALUES(steamname);
Query OK, 0 rows affected (0.02 sec)
Note it says "0 rows" were inserted by that statement.
But this still doesn't allow you to change an existing steamname. If you specify a new name, it'll just insert a new row. If you specify the name that's already in use, it's a duplicate so it won't insert a new row, but it won't change the name either.
How do you expect the INSERT statement to apply to an existing row if you let it auto-increment a new ID value? Which existing row do you think it should conflict with?
Re your second comment:
You don't need a secondary unique key, I'm just trying to show you how IODKU works.
Before thinking about the SQL syntax, you have to think about the logic of the problem. In other words, if you specify a new name, which existing row do you want it to replace?
For example:
mysql> insert into names (id, steamname) values (123, 'Chatyak')
on duplicate key update steamname = VALUES(steamname);
This would work, because if a row exists with ID 123, this INSERT will cause a duplicate key conflict and therefore the ON DUPLICATE KEY clause will be triggered. But where did we get the value 123 in this example? Presumably in your application, you know what id you think you're updating. Is there a variable for that? Does it correspond to the user's session data?
**************************Edit:*************************
In response to the answer provided by #Rahul. This statement:
INSERT INTO names (steamname)
VALUES ('$profile')
ON DUPLICATE KEY UPDATE ID = LAST_INSERT_ID(ID), steamname = VALUES(steamname)
is technically valid but will always affect exactly 0 rows no matter what. Actually there are so many things wrong with it, that it is difficult to enumerate them all (which is the reason for this edit).
The usage of ON DUPLICATE KEY UPDATE id = LAST_INSERT_ID(id) given in MySQL docs at the bottom of this page is an example of how to capture the id value of a row that has been updated i.e not inserted, since otherwise LAST_INSERT_ID() (with no argument) would return the last inserted id, which in the case of an update would not be meaningful in terms of the row in question.
So the above statement, if it ever worked — though it can't — would be effectively no different from this statement:
INSERT INTO names (steamname)
VALUES ('$profile')
ON DUPLICATE KEY UPDATE steamname = VALUES(steamname)
Except that you would also be updating that row's id value to the value it already was.
Aside from that, the reason the statement can never work is because the ON DUPLICATE KEY UPDATE clause will never be evaluated unless there is a duplicate key. And the same error that would occur without the ON DUPLICATE KEY UPDATE clause, will occur when we try to update steamname to equal the value of steamname i.e. the same value that tripped the ON DUPLICATE KEY UPDATE clause in the first place.
*****************************END OF EDIT***********************************
First: $profile is still an instance of SimpleXMLElement object when you try to use it in your query. So the SimpleXMLElement::__toString method is called, but SimpleXMLElement::__toString method only returns text content from directly inside the first element, and not text from any descendants. So if you have some element <steamname> and some element <steamID> nested within the parent element returned by your call to simplexml_load_file, their values will not be returned. See manual.
Second: when using the VALUES function with an UPDATE clause, the correct syntax is to refer to a column name/s like so DUPLICATE KEY UPDATE colname = VALUES(some_col_name). If you want to use an explicit value the syntax is DUPLICATE KEY UPDATE colname = 'value'. See manual.
Third: since you have id set to AUTO_INCREMENT, any rows inserted into the names table without explicitly inserting an id value or using a WHERE clause to specify an id value will create a new row with a new auto incremented id value, regardless of whether you use DUPLICATE KEY UPDATE or not because AUTO_INCREMENT will ensure that you never generate a duplicate key.
I think you may be able to make use of mysql's REPLACE statement instead. It's the simplest query that works for your described needs.
REPLACE INTO `names` (`id`,`steamname`)
VALUES ($id, $steamname)
where $id is $profile->steamID, and $steamname is the new(or not new) value for that row's steamname column.
The REPLACE statement will simply DELETE and then INSERT where an id value already exists. But since you're inserting the same id the effect is of updating the value of steamname in the row that contains a matching id value. Just be aware that if you have other columns besides id and steamname in the same table and you don't include their values in the REPLACE statement's VALUES then those values will be lost.
Fourth: for debuging these kinds of things its important to a) know what values you're actually passing into your query string. b) know that the basic query syntax you're using is correct, apart from any specific values you are(or aren't) using with it.
And finally: make things easy on yourself; since you're already using object notation with SimpleXMLElement to access element values, why not use it with mysqli also? Try this. It is UNTESTED, but it think it will work for you.
<?php
// Capture person's name and id from XML file
$profile = simplexml_load_file('UrlGoesHere.Com/?xml=1', 'SimpleXMLElement', LIBXML_NOCDATA);
$profile_id = (string)$profile->steamID;
$profile_name = (string)$profile->steamName;
//connect to database
$mysqli = new mysqli("localhost","username","password","databaseName");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
//build query
//IMPROTANT: this will delete other fields(if any)
//> in the row, unless they are also refilled by this statement
$q = ("
REPLACE INTO `names` (`id`,`steamname`)
VALUES (?, ?)
");
//uncomment to debug query
//echo "<pre>$q</pre>";
//uncomment to debug values
//echo "<pre>profile_name: \n $profile_name</pre>";
//echo "<pre>profile_id: \n $profile_id</pre>";
//prepare statement using above query
$stmt = $mysqli->prepare($q);
//fill in '?'s with actual values
//first argument is the data types
//'i' [integer] 's' [string]
//follownig aruments fill in '?'s in order
$stmt->bind_param('is', $profle_id, $profile_name);
// execute statement
$stmt->execute();
//close statement
$stmt->close();
//close connection
$mysqli->close();
?>
I am running a insert statement to insert data, but I want to check for any duplicate entries based on date and then do an entry.
All I want is if today a user enters product_name='x', 'x' is unique so that no one can enter product name x again today. But of course the next day they can.
I do not want to run a select before the insert to do the checking. Is there an alternative?
You can either use
1. Insert into... on duplicate update
2. insert.. ignore
This post will answer your question
"INSERT IGNORE" vs "INSERT ... ON DUPLICATE KEY UPDATE"
You can use the mysql insert into... on duplicate update syntax which will basically enter in a new row if one isn't there, or if the new row would have caused a key constraint to kick in, then it can be used to update instead.
Lets say you have the following table:
MyTable
ID | Name
1 | Fluffeh
2 | Bobby
3 | Tables
And ID is set as the primary key in the database (meaning it CANNOT have two rows with the same value in it) you would normally try to insert like this:
insert into myTable
values (1, 'Fluffster');
But this would generate an error as there is already a row with ID of 1 in it.
By using the insert on duplicate update the query now looks like this:
insert into myTable
values (1, 'Fluffster')
on duplicate key update Name='Fluffster';
Now, rather than returning an error, it updates the row with the new name instead.
Edit: You can add a unique index across two columns with the following syntax:
ALTER TABLE myTable
ADD UNIQUE INDEX (ID, `name`);
This will now let you use the syntax above to insert rows while having the same ID as other rows, but only if the name is different - or in your case, add the constraint on the varchar and date fields.
Lastly, please do add this sort of information into your question to start with, would have saved everyone a bit of time :)
I believe the question have emerged as my irritation of doing twice as much work as I could imagine is necessary.
I accept the idea that I could be lacking experience with both MySQL and PHP to think of a simpler solution.
My issue is that I have several tables (and I'd might be adding more) and of these is a parent table, only containing two fields - an id (int) and a name identifying it.
At this moment, I have seven tables with at least 15 fields in each one. Every table has a field, containing the id which I can link to the parent table.
All of these data isn't required to be filled - you will just have to create that one entry in the parent table. For the other tables, I have separate forms.
Now, these forms are made for updating the data in the fields, which means I have to pull out the data from the table if any data is available.
What I would like to do is when I receive the data from my form, I could just use an UPDATE query in my model. But if the table I want to update doesn't have an entry for that specific id, I need to do an insert.
So, my current pseudo code is like this:
$sql = "SELECT id FROM table_x WHERE parent_id = ".$parent_id;
$res = $mysql_query($sql);
if( mysql_num_rows($res) == 1 )
{
$sql = "UPDATE table_x SET ... WHERE parent_id = ".$parent_id;
}
else
{
$sql = "INSERT INTO table_x VALUES ( ... )";
}
mysql_query($sql);
I have two do this for every table I have - can I do something different or smarter or is this just the way it has to be done? Cause this seems very inefficient to me.
Use
INSERT ... ON DUPLICATE KEY UPDATE Syntax
It will insert if record not found,
otherwise, it will update existing record,
and you can skip the check before insert - details
This assuming relation for each 7 table to the parent table is 1:1
Or use REPLACE instead of INSERT - it's an insert, but will do an DELETE and then INSERT when a unique key (such as the primary key) is violated.
in mysql you can do this:
INSERT INTO table
(
col1,
col2
) VALUES(
'val1',
'val2'
) ON DUPLICATE KEY UPDATE table SET
col2 = 'val2'
take a look at the documentation for more information
mysql_query("UPDATE table table_x ..... WHERE parent_id=".$parent_id);
if (mysql_affected_rows()==0) {
mysql_query("INSERT INTO .....");
}