I have an array of information about links I've found on a webpage in a PHP script.
Each link needs to be inserted into a MySQL myisam table.
Right now, I loop through the array and run an insert query for each link.
Is there a more appropriate way to do this so that I'm using MySQL more efficiently?
You can insert several records with a single statement:
<?php
// Our MySQL query
$sql = "INSERT INTO beautiful (name, age)
VALUES
('Helen', 24),
('Katrina', 21),
('Samia', 22),
('Hui Ling', 25),
('Yumie', 29)";
mysql_query( $sql, $conn );
?>
Source: http://www.desilva.biz/mysql/insert.html
You can insert multiple values in a single statement using the following syntax:
INSERT INTO tbl_name (a,b,c) VALUES(1,2,3),(4,5,6),(7,8,9);
see Section 12.2.5 of the MySQL manual
This is especially advisable if the MySQL server is on a different host than the PHP server: in the example above, you need only a single network roundtrip rather than three.
If network latency is not an issue (if the MySQL server runs on the same server as PHP), use prepared statements like this:
$dbh = new PDO("mysql:host=127.0.0.1;port=3306;dbname=test", "root", "");
$sth = $dbh->prepare("INSERT INTO links(title, href) VALUES(:title, :href);");
while ($link = getNextLink()) {
$sth->execute( array( "title" => $link->title, "href" => $link->href ) );
}
Prepared statements are slightly faster when executed repeatedly, because the MySQL server has to parse the SQL and run the query planner/optimizer only once.
If the table has indices, you can disable them before inserting and enable them again after inserting, this makes inserting rows faster because the indices don't have to be updated after every insert (only possible for MyISAM, see section 12.1.7 of the Mysql manual):
ALTER TABLE links DISABLE KEYS
-- insert rows
ALTER TABLE links ENABLE KEYS
A while or a for each loop is sufficient enough I would think for this, seeing as the information is going to be large and I imagine dynamic.
You can use one query but if you have hundreds or thousands of pieces of information, or if you are going to be constantly updating the database with new data, then an array with a for each or while loop is best for this. If its just a one off with only a few pieces of information then just write out the QUERY yourself as follows
mysql_query("INSERT INTO table (column1, column2)
VALUES
('VALUE','VALUE'),('VALUE','VALUE')");
Related
In the old question asked below the top answer describes how to speed up the MySQL insert process. Since this an old question I'm curious on how to do this with prepared statements. I use MySQL with innoDB. I'll paste in an example from the answer here for people who don't want to check the link.
Here I'll describe 3 methods for inserting data, ranging from slow to
fast:
The following is extremely slow if you have many rows to insert:
INSERT INTO mytable (id,name) VALUES (1,'Wouter');
INSERT INTO mytable (id,name) VALUES (2,'Wouter');
INSERT INTO mytable (id,name) VALUES (3,'Wouter');
This is already a lot faster:
INSERT INTO mytable (id, name) VALUES
(1, 'Wouter'),
(2, 'Wouter'),
(3, 'Wouter');
And this is usually the fastest:
Have CSV file that looks like this:
1,Wouter
2,Wouter
3,Wouter
And then run something like
LOAD DATA FROM INFILE 'c:/temp.csv' INTO TABLE mytable
old question
This is obvious an old answer. I want to know how to do this with prepared statements in a way that will insert as fast as possible, but let's go one step at a time. First I want to know how to do this with a prepared statements. Any examples that can be given will be much appreciated. I will reply or edit this question with any extra information that you may need.
I'm using mysqli_ *Edited for Rick James's question.
I'm going to do my best and make an educated guess on how this can be done. Please correct me if I'm wrong.
I think I can convert
INSERT INTO mytable (id, name) VALUES
(1, 'Wouter'),
(2, 'Wouter'),
(3, 'Wouter');
into
$bindParamsToBuild = '($myArray[key], ?,?),'
for (i = 0; i < count($myArray); i++)
{
if (i === count($myArray))
{
$bindParamsToBuild += '($myArray[key], ?,?);';
}
else
{
$bindParamsToBuild += '($myArray[key], ?,?),';
}
}
"INSERT INTO mytable (id, name) VALUES".$bindParamsToBuild;
Are you using PDO or mysqli?
If using mysqli, use real_escape_string() separately on each item in the list. It is a bit tedious but can be made easier by gradually building the insert string. I suggest not putting more than 100 items into a single INSERT.
https://stackoverflow.com/a/780046/1766831 is a pretty good discussion of the details. (But be sure to use mysqli_*, not mysql_*.)
Plan A: Construct the query as discussed in some of those links. Use real_escape_string and PHP string operations instead of "prepare".
Plan B: Build a string with lots of question mark. Simultaneously, build an array with the values to put into those question marks. Then do a single "prepare" to finish the multi-row INSERT statement.
I have a DB table which has approximately 40 columns and the main motive is to insert the records in the database as quickly as possible. I am using PHP for this.
The problems is, to create the insert statement, I have to loop through a for each. I am not sure if I doning this correctly. Please suggest me the best atlernative.. here is the example..
/// to loop through the available data ///
$sqc = "";
for ($i=1; $i<=100; $i++){
if ($sqc == ""){
$sqc = "('".$array_value["col1"]."'.. till .. '".$array_value["col40"]."',)";
} else {
$sqc .= ",('".$array_value["col1"]."'.. till .. '".$array_value["col40"]."',)";
}
}
/// finally the sql query ///
$sql_quyery = "INSERT INTO table_name (`col1`,.. till.. ,`col40`) values ".$sqc;
This concatenation of $sqc is taking a lot of time. and also the insertion in the DB, is there an alternate way of doing this.. i need to find a way to speed this up like 100X.. :(
Thank you
As suggested on MySQL Optimizing INSERT Statements page, there are some ways for this-
If you are inserting many rows from the same client at the same time, use INSERT statements with multiple VALUES lists to insert several rows at a time. This is considerably faster (many times faster in some cases) than using separate single-row INSERT statements. If you are adding data to a nonempty table, you can tune the bulk_insert_buffer_size variable to make data insertion even faster.
When loading a table from a text file, use LOAD DATA INFILE. This is usually 20 times faster than using INSERT statements.
Find the link below-
[MySQL Guide]
[1] https://dev.mysql.com/doc/refman/5.7/en/insert-optimization.html
Is just a small contribute but you can avoid the concat using a binding
$stmt = mysqli_prepare($yuor_conn,
"INSERT INTO table_name (`col1`,.. till.. ,`col40`) VALUES (?, ... till.. ?)");
mysqli_stmt_bind_param($stmt, 'ss.......s',
$array_value["col1"], $array_value["col2"], .. till..,
$array_value["col40"]);
How do I join these two queries and execute them as a single query to insert values in two tables:
$sql = mysql_real_escape_string('INSERT INTO admin_export(datetime, product_name, item_code,quantity,subject,export_no) VALUES').implode(',', $row_data);
$sql2 = "insert into `itflower_exportno` (admin_exportno) values('$exportno1')";
You need to separate your two INSERT statements with a semicolon into the single variable.
This(mysql_*) extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should be used. Switching to PreparedStatements is even more better to ward off SQL Injection attacks !
You can however use transactions as following example.
BEGIN;
INSERT INTO users (username, password)
VALUES('test', 'test');
INSERT INTO profiles (userid, bio, homepage)
VALUES(LAST_INSERT_ID(),'Hello world!', 'http://www.stackoverflow.com');
COMMIT;
What you have in the code are two different inserts.
MySQL doesn't allow for multiple inserts to be run in the same query so you will have to do one first and then the other.
However you can insert multiple rows in the same table in just one query, basically you are restricted to do all the insert you want in one table at a time.
You can't do this.
If you want to do it because you are afraid of the integrity of the data, use transaction .
Second, use suitable transaction isolation level, to ensure that data are reading correctly.
I have only just begun learning about joining tables in MySQL. Now, I have a small project where I simply want to let the visitor insert data through a form. The data is then displayed in a HTML table with four rows, joining together two tables in my database. The "problem" is that the data should be submitted into those two different tables in my database.
I tried
$query = "INSERT INTO table1, table2 (col1, col2, col3, col4) VALUES ('value1', 'value2', 'value3', 'value4')";
but that doesn't seem to do it. What is the correct syntax for submitting form data to several database tables? Oh, and I read some similar threads mentioning using transactions. Is this necessary? My tables are run with MyISAM. Thanks!
You can read more about it from the MySQL Manual. In short, you cannot insert into multiple tables at once. This leaves you with three options:
Multiple INSERT statements
Triggers
Stored Procedures
The answer to this question: MySQL Insert into multiple tables? (Database normalization?) suggests using transactions, which will not work with MyISAM, but is a good FYI if you ever switch to InnoDB.
I really recommend you read up on Triggers. They can make your life a lot easier. But if you don't want to use them, look into PHP's mysqli_multi_query, which will allow you to execute two different queries at the same time, for example:
$query = "INSERT INTO table1 (col1,col2) VALUES ('$value1','$value2');";
$query = "INSERT INTO table2 (col3,col4) VALUES ('$value3','$value4');";
$result = mysqli_multi_query($dbcon, $query);
You can perform this by using MySQL Transactions By:
Try:
BEGIN
INSERT INTO table1 (col1, col2...ETC)
VALUES('value1', 'value2'...ETC)
INSERT INTO table2 (col1, col2...ETC)
VALUES('value1', 'value2'...ETC);
COMMIT;
With MyISM you will need to execute the query for each table you want to insert into, I do not believe that in a single query you can add to multiple tables.
In your case you can not use Transactions because they are not supported by your engine.
Your only solution is to use several separate queries, preferably within a transaction. Transactions are necessary if you want to make sure that the data from each query is inserted, in which case you COMMIT the transaction; should one of the queries fail, you can ROLLBACK.
P.S. Use InnoDB. It's better in pretty much any environment where INSERT queries make up at least 5% of all queries (sadly I cannot give the source as I had read it several months ago and no longer remember where).
I may be wrong, but you don't insert into multiple tables at the same time. You split it into two or more commands, each handling the specific insertion, whats the big deal, that one extra line of code (which makes everything clearer) too much of a hassle to type?
Look at it this way, if you write a large script, for instance a routine to process some data, the more you segment the code, the easier it is to debug, and, if necessary, inoculate instructions that are problematic, it will end up saving you time in the long run.
I have this problem before You can use multiple query function
$query = "INSERT INTO table1 (col1,col2) VALUES ('$value1','$value2')";
$query = "INSERT INTO table2 (col3,col4) VALUES ('$value3','$value4')";
$result = mysqli_multi_query($dbcon, $query);
I have to insert 50,000 to 16.000.000 rows in MySQL Table from php. It is taking at least 15-20 min to store in database.
To complete my project i have to do it more faster insertion. do anyone having any flexible opinion.
i am using this code
for($i=$d;$i<=$fd;$i++)
{ $j = $i-$d+1;
$sql1 = "INSERT INTO information(id, redirection, username, pc, date, time,
method,text, http, code, data, request, software) VALUES ('".$i."','"
.$_SESSION["redirection"][$j]."','".$_SESSION["username"]$j]."','"
.$_SESSION["pc"][$j]."','".$_SESSION["date"][$j]."','".
$_SESSION["time"][$j]."','".$_SESSION["method"][$j]."','"
.$_SESSION["text"][$j]."','".$_SESSION["http"][$j]."','"
.$_SESSION["code"][$j]."','".$_SESSION["data"][$j]."','"
.$_SESSION["request"][$j]."','".$_SESSION["software"][$j]."')";
mysql_query($sql1);
}
I agree with Cal. Try this:
$sql1 = "INSERT INTO information(id, redirection, username, pc, date, time,
method,text, http, code, data, request, software) VALUES ";
<?php
for($i=$d;$i<=$fd;$i++)
{
$j = $i-$d+1;
$sql1 .= "('".$i."','"
.$_SESSION["redirection"][$j]."','".$_SESSION["username"]$j]."','"
.$_SESSION["pc"][$j]."','".$_SESSION["date"][$j]."','"
.$_SESSION["time"][$j]."','".$_SESSION["method"][$j]."','"
.$_SESSION["text"][$j]."','".$_SESSION["http"][$j]."','"
.$_SESSION["code"][$j]."','".$_SESSION["data"][$j]."','"
.$_SESSION["request"][$j]."','".$_SESSION["software"][$j]."')";
if($i<=$fd){
$sql1 .= ", ";
}
}
mysql_query($sql1);
?>
In this case you will perform only one insertion instead multiple. Also, as variant, you can store your data into text file (.csv, for example) and then import it into your database. But this is exotic method.
Use extended insert syntax to insert multiple rows per statement:
INSERT INTO tbl_name (a,b,c) VALUES(1,2,3),(4,5,6),(7,8,9);
http://dev.mysql.com/doc/refman/5.5/en/insert.html
Another trick is to disable/delete indexes and enable/add them after all data has been inserted.
DISABLE KEYS;
INSERT ......
ENABLE KEYS;
If the table supports transactions (InnoDB), you can speed up bulk inserts by doing everything inside a single transaction. Query BEGIN TRANSACTION before all the inserts, and COMMIT after you're done.
Obviously, this is irrelevant if your table doesn't support transactions (MyISAM).
Prepared statements are another way to speed up bulk inserts (with added security benefits), but it's difficult to do that in a project that uses mysql_query() everywhere, so I'll leave that out.
You're not really clear what your limits are, and especially WHY. Other answers assume you are on some sort of time-schedule, and need the insert completed before a certain moment
But when we assume you want to have control over your program back as quickly as possible, but not neccesairily need the insert to be finished, you could use delayed inserts?
http://dev.mysql.com/doc/refman/5.5/en/insert-delayed.html
The DELAYED option for the INSERT statement is a MySQL extension to
standard SQL that is very useful if you have clients that cannot or
need not wait for the INSERT to complete. This is a common situation
when you use MySQL for logging and you also periodically run SELECT
and UPDATE statements that take a long time to complete.
When a client uses INSERT DELAYED, it gets an okay from the server at
once, and the row is queued to be inserted when the table is not in
use by any other thread.