Update a row if exists, if not create a new one MySQL - php

I am inserting a name, number, and company into a DB.
My table is simply:
id(primary key)
name
slideView
company
I need to update this information if a name passed to it exists, if not create a new row with this data. I have looked at REPLACE INTO but I dont think that will work for me... as I dont touch the ID at all.
My code is:
insertData($name,$count,$company);
function insertData($name, $count, $company) {
#Try/Catch statement to connect to DB, and insert data
try {
#DB username/password
$usernameDB = '****';
$passwordDB = '****';
#Create new PHP Database Object with the address, username, and password as parameters
$pdo = new PDO('mysql:host=localhost;dbname=*****', $usernameDB, $passwordDB);
#Set pdo attributes to handle errors
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
#assign the sth variable (sth means statement handle) to insert the data
$sth = $pdo->prepare("REPLACE INTO ***** SET name = ?, slideView = ?, company = ?");
#Execute the insert
$sth->execute(array($name,$count,$company));
#Error if can't connect or insert
} catch(PDOException $e) {
echo 'Error: ' . $e->getMessage();
}#/try
}
I'm new to SQL and havnt found a good way to do this yet.

You might be better of using the insert ... on duplicate update syntax for this, although it will mean passing a few extra params but it can quash certain problems in the replace into syntax that seem to keep cropping up.
REPLACE INTO ***** SET name = ?, slideView = ?, company = ?
Could be written as:
insert into yourTableName (name, slideView, company)
values (:name, :slideView, :company)
on duplicate key update set
slideView=:$slideView2, company=:company2
and then the execute is done like this:
$sth->execute(array(':name' => $name, ':slideView' => $count,
':company' => $company, ':slideView2' => $count, ':company2' => $company));
The format above uses named paramaters (they are ever so much easier to read/debug) and will insert a new row into the database - or if the unique/primary key column name already has the value, then update the row with the remainder of the information.
You do have to use paramaters twice here (even though slideView and company will contain the same information) as no parameter can be used twice in a query.

REPLACE INTO should work just fine - it also checks for columns with UNIQUE constraints. So you would just need to mark your name column as unique so that REPLACE INTO will identify it as duplicate.
I haven't tried this particular use case, but the documentation seems to allow it.

Related

Insert Multiple Value into table MySQL if not exists

I have a table with 3 columns (ID, username, full name), I want the ID to be AUTOINCREMENT. I want to insert into the table only if it does not already exist in the table.
This is my Code:
$fullName = $_POST['fullname'];
$username = $_POST['username'];
$dbhost = "localhost";
$dbname = "databasename";
$dbusername = "root";
$dbpassword = "";
$link = new PDO("mysql:host=$dbhost;dbname=$dbname","$dbusername","");
$statement = $link->prepare('INSERT INTO accounts (username, fullname)
VALUES (:username, :fname)');
$statement->execute([
'fname' => $fullName,
'username' => $usernameget,
]);
If your id is already autoncrement then you no need to mention in query.
You can simply write below query
insert into accounts (username,fullname) values( $username , $fullname )
you can do this with if else condition in PHP
$fullname = $_POST['fullname'];
$username = $_POST['username'];
$chk = mysqli_query("select * FROM `accounts` where fullname='$fullname' and username='$username'");
$rs = mysqli_fetch_array($chk);
if($rs == "")
{
$ins = mysqli_query("INSERT INTO `accounts`(fullname,username) VALUES ('$fullname','$username'))";
}
else{
echo "Duplicate entry";
}
or you can do this by SQL Query also.
INSERT INTO accounts(username,fullname)
SELECT * from (SELECT '$username', '$fullname') AS tmp
WHERE NOT EXISTS
(SELECT username FROM accounts WHERE username='$username')
There's several things to fix here.
Don't specify column values if you don't need to, or don't care about the value. Only specify if necessary or relevant. In this case id should be omitted.
Always use placeholder values for your user data. Never put $_GET or $_POST data directly in a query.
To avoid duplication add a UNIQUE constraint on the table.
To fix that you do adjust your code:
// Enable exceptions, avoiding the need for manual error checking
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
// Try and keep the order of things like this consistent through your code
$username = $_POST['username'];
$fullname = $_POST['fullname'];
// Here using a short, common name for the database handle $db
$db = new mysqli("localhost","root","","database");
// Prepare your insert first as a query with no data, only placeholders
$db->prepare("insert into accounts (username,fullname) values(?,?)");
// Bind the data to the placeholders, here two string ("s") values.
$db->bind_param('ss', $username, $fullname);
// Execute the query
$db->execute();
To add the UNIQUE constraints use CREATE INDEX:
CREATE INDEX idx_accounts_username (username);
CREATE INDEX idx_accounts_full_name (full_name);
That has to be run in your MySQL shell, not PHP.
When a UNIQUE constraint is in place MySQL will not allow duplicate data. Note that NULL values don't count, and can be "duplicated". Set NOT NULL on your columns to force them to be completely unique.
As your id is autoincrement primary key, so you can create or update it with:
insert into accounts (username,fullname) values( $username , $fullname ) on duplicate key update username = '$username',fullname = '$fullname'
To get correct answers, a question must be asked with as much explanation as possible. you should atleast tell what have you done and then what are you getting.
As far as i have understood, to achieve your goal, the table structure must be changed and inserting query also.
Remember to accept the answer and click the upvote button if the answer satisfies you,else give more information in the question, so that members here, can give right answers.
If you understand table creating queries go to bottom of this answer or else do as follows:
if you use gui to create table,
1. click on create new table.
2. in the right pane give table name and column names as shown. (dont give space in 'full name' instead give 'full_name' or 'fullname')
3. scroll the winow to the right till you see A_I column as shown.
4. tick the first line (which we have used as id), 'add index' box will appear.
just click here go (at the bottom).
you will be redirected to table list as shown.
6. open (click) your table again.
7. click on structure.
now suppose you don't want duplicates in 'username' column, click this column and click on 'unique' as shown
if you don't want duplicate when both the columns' value together, click both the columns and then click 'unique' as shown
if you understand create table commands:here is the sql for above:
CREATE TABLE accounts (
id int(11) NOT NULL AUTO_INCREMENT,
username varchar(25) NOT NULL,
fullname varchar(55) NOT NULL,
PRIMARY KEY (id),
UNIQUE KEY username (username)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
with above table structure records will be autoincremented and duplicate names will not be added. (remember to handle duplicate entries error in you inserting querie withINSERT IGNORE INTOwith this your query will be:
$statement = $link->prepare('INSERT IGNORE INTO accounts (username, fullname)
VALUES (:username, :fname)');
or you can also useON DUPLICATE KEY)
First set your primary key (eg. id) if not set as auto increment
Second use multiple insertion value
INSERT IGNORE INTO accounts (username,fullname) VALUES ("p","k"),("c","s");
IGNORE keyword is use to duplicate
IF you want to see with PDO

Find and Post in table using php

I'm trying to upload data to a existing User database I have stored online. I need to post the user phone number string in the user specified row. Using android and php, is there any way to post extra info in an existing row?
I think I'm not choosing WHERE to put that extra info.
<?php
require "indioPhP.php";
$username = $_POST["username"];
$phoneNumber = $_POST["phoneNumber"];
$statement = mysqli_prepare($con, "SELECT * FROM User WHERE username = ?");
mysqli_stmt_bind_param($statement, "s", $username);
mysqli_stmt_execute($statement);
$sql ="insert into User values('$phoneNumber')";
if(mysqli_query($con,$sql)){
echo "Gracias por registrarte!";
} else{
echo "error in insertion".mysqli_error($con);
}
?>
Ok now i see your Problem:
Update User set phonenumber=? where username=?
You Need something like this ? it's only one query where you search the user and Change it. Try to read more about SQL. Your code Looks a bit confused, with prepared Statements and normal statments in the same block.
Edit:
The statement insert adds a new line in the table wheras update modifies an existing one. Assuming your table User has 4 columns: username, firstname, lastname, phonenumber, for insert, the syntax is either
insert into user values("jdoe", "John", "Doe", "555 7565")
or
insert into user(username, phonenumber) values ("jdoe", "555 7565")
In the first case, as columns are not specified, you must give all of them.
In the second case, you insert a new line specifying only some columns. The other ones will take their default values. If a missing column doesn't have a default value, you will have an error.

SQL INSERT INTO table results in duplicates

I have a script that I have setup a CRON for that is getting values from a 3rd party server via JSON (cURL)
Right now every time the cron runs it will INSERT a completely new record. Causing duplicates, and resulting me in manually removing the dups.
How would I go about preventing duplicates, and only update the information that is either missing, or different from the NEW $VAR values?
What I want to do can be expressed like this: IF old value is NOT new value use new value else use old value;
if ($stmt->num_rows !== 1) {
if ($insert_stmt = $mysqli->prepare("
INSERT INTO members (
start_date
)
VALUES (?)"))
{
$insert_stmt->bind_param('s',
$StartDate,
);
if (! $insert_stmt->execute()) { echo ''; }
}
}
}
You should try using INSERT ... ON DUPLICATE KEY UPDATE. Documentation
This does mean that you will have to define some unique (could be primary) key to the table that is always constant so MySQL knows what to update.
A quick example of how you would do it:
INSERT INTO table (f1,f2,f3) VALUES ('something_unique',2,5)
ON DUPLICATE KEY UPDATE f2=2,f3=5
The following statement will be silently ignored if one of the fields with the flags UNIQUE or PRIMARY KEY already exist in the database. If you're searching for INSERT IF NOT EXISTS this is probably what you're looking for:
INSERT IGNORE INTO `members` SET name='Steve',start_date='2015-11-20';
You can also overwrite a record that already exists using REPLACE. If it doesn't yet exist, it will be created:
REPLACE INTO `members` SET name='Steve',start_date='2015-11-20';
Another thing to consider would be INSERT ... ON DUPLICATE KEY UPDATE syntax:
INSERT INTO table (a,b,c) VALUES (1,2,3)
ON DUPLICATE KEY UPDATE c=c+1;
UPDATE table SET c=c+1 WHERE a=1;
I ended up writing another if statement to check if a unique value existed from incoming and the existing db value existed and leaving it blank to prevent it from importing duplicates. I also wrote a separate file to update where values differentiate between what I am receiving as (new) and what is in the database (old) which actually worked out great for my application.
Here is my answer for anyone else that runs into this issue :)
$prep_stmt = "SELECT * FROM table WHERE column_keys=?";
$stmt = $mysqli->prepare($prep_stmt);
if ($stmt) {
$stmt->bind_param('s',$varvalues);
$stmt->execute();
$stmt->store_result();
if ($stmt->num_rows == 1) {
if ($insert_stmt = $mysqli->prepare("")) {
$insert_stmt->bind_param('');
if (! $insert_stmt->execute()) {
echo 'shits broke'; }
}
}
else { if ($insert_stmt = $mysqli->prepare("
INSERT INTO table (column_keys)
VALUES (?)")) // you will need a ? per column seperate by a , (?,?,?...?)
{ $insert_stmt->bind_param('s',
$varvalues
); // you will also need to bind a 's' (string) 'i' for num, etc per $var value.
if (! $insert_stmt->execute()) { echo 'shits broke';} //lol
}
}
}
Also a simple error reporting trick I stumbled upon that helped me clean up a few things I overlooked. Just place it at the top of the file, or above you want to debug ;)
error_reporting(E_ALL);

Can While Loop be used for Error Catching?

I am using try catch algorithm when inserting a record to a MySQL table. My scripting language is PHP.
try {
/*
UDID generation algo goes here.
*/
$sql = "INSERT INTO tablex (udid, name)
VALUES ('$udid', 'Doe')";
$conn->exec($sql);
echo "New record created";
}
catch(PDOException $e)
{
echo "Error"
}
$conn = null;
How do I re-write the above so that instead of try catch, I use a loop. If there is an error, try again. Break out of the loop if there is no error.
There is "While True" but I don't know if the "Try Catch" should be part of the While True loop..
The purpose of this is to save a UDID - the unique value is set in MYSQL. If I generate the same value, I may get the error. Hence, why the loop.
I feel like you're going about this the wrong way. Instead of trying to insert a value that might not be unique, I would try to see if that value exists first. You could perform a query such as
do {
//$udid = create uuid
$query = "SELECT COUNT(*) FROM tablex WHERE udid = :udid";
$statement = $pdo->prepare($query);
$statement->bindValue("udid", $udid);
$result = $statement->fetchAll();
} while ($result["count"] === 1);
//insert row into table
This is just off the top of my head and it can be refactored even better. You could also leverage your database to generate the UDID for you if you prefer. You could run a query to get all of the udid's from your table and just run in_array to check to see if the value is there, then you're only hitting your database twice. Anyway, you really don't want to try to abuse a try catch like that.
mysql has a function for something like this you would add an "ON DUPLICATE KEY UPDATE" to your insert statement
Example:
INSERT INTO table(x, y, z) values (?, ?, ?) ON DUPLICATE KEY UPDATE x=?;
Also see this link for more info:
http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html

PDO insert new record to database based on lastInsertId()

Ive just started learning PDO and I'm struggling by simply inserting a new record based from
$lastid = $db->lastInsertId();
The ID gets created in the database table from another function.
But nothing happens when i try to insert a new record based on that ID.
function add_name($last_id, $name) {
$db = some_db();
$query = "INSERT INTO team (name) VALUES (:name) WHERE id = '".$last_id."'";
$stmt = $db->prepare($query);
$stmt ->bindParam(':name', $name, PDO::PARAM_STR);
$stmt->execute();
}
INSERT ... WHERE is not valid SQL. If you are inserting a new record, an autoincremnt ID will be generated at that time (if you have such defined for the table).
If you are trying to INSERT a new row into a related table with the last id from another table, then you would set that value as one of your column inputs. So the workflow would look like this:
INSERT [column data for table_a] INTO table_a
[GET autoincrement from last insert]
INSERT (table_a_foreign_key_column, [other table_b columns]) VALUES (table_a_id, [other table_b values) INTO table_b
UPDATE:
Since UPDATE is what you want, you can make update like this:
UPDATE team
SET name = :name
WHERE id = :id
You should use parameters for both name and id values. It is still not clear to me why you would need to make an insert and then an update within the same script execution. It's not like you received any more input from the user that you did not already have. I would guess you could just insert this name values when first creating the record and save yourself the extra trouble of multiple queries.
i think your sql query is wrong, try this:
function add_name($last_id, $name) {
$db = some_db();
$query = 'INSERT INTO team (id, name) VALUES (:id, :name)';
$stmt = $db->prepare($query);
$stmt ->bindParam(':name', $name, PDO::PARAM_STR);
$stmt ->bindParam(':id', $last_id, PDO::PARAM_INT);
$stmt->execute();
}
MySQL Insert Where query

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