Related
How to get the next id in mysql to insert it in the table
INSERT INTO payments (date, item, method, payment_code)
VALUES (NOW(), '1 Month', 'paypal', CONCAT("sahf4d2fdd45", id))
You can use
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'table_name'
AND table_schema = DATABASE( ) ;
or if you do not wish to use information_schema you can use this
SHOW TABLE STATUS LIKE 'table_name'
You can get the next auto-increment value by doing:
SHOW TABLE STATUS FROM tablename LIKE Auto_increment
/*or*/
SELECT `auto_increment` FROM INFORMATION_SCHEMA.TABLES
WHERE table_name = 'tablename'
Note that you should not use this to alter the table, use an auto_increment column to do that automatically instead.
The problem is that last_insert_id() is retrospective and can thus be guaranteed within the current connection.
This baby is prospective and is therefore not unique per connection and cannot be relied upon.
Only in a single connection database would it work, but single connection databases today have a habit of becoming multiple connection databases tomorrow.
See: SHOW TABLE STATUS
This will return auto increment value for the MySQL database and I didn't check with other databases. Please note that if you are using any other database, the query syntax may be different.
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'your_table_name'
and table_schema = 'your_database_name';
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'your_table_name'
and table_schema = database();
The top answer uses PHP MySQL_ for a solution, thought I would share an updated PHP MySQLi_ solution for achieving this. There is no error output in this exmaple!
$db = new mysqli('localhost', 'user', 'pass', 'database');
$sql = "SHOW TABLE STATUS LIKE 'table'";
$result=$db->query($sql);
$row = $result->fetch_assoc();
echo $row['Auto_increment'];
Kicks out the next Auto increment coming up in a table.
In PHP you can try this:
$query = mysql_query("SELECT MAX(id) FROM `your_table_name`");
$results = mysql_fetch_array($query);
$cur_auto_id = $results['MAX(id)'] + 1;
OR
$result = mysql_query("SHOW TABLE STATUS WHERE `Name` = 'your_table_name'");
$data = mysql_fetch_assoc($result);
$next_increment = $data['Auto_increment'];
Use LAST_INSERT_ID() from your SQL query.
Or
You can also use mysql_insert_id() to get it using PHP.
Solution:
CREATE TRIGGER `IdTrigger` BEFORE INSERT ON `payments`
FOR EACH ROW
BEGIN
SELECT AUTO_INCREMENT Into #xId
FROM information_schema.tables
WHERE
Table_SCHEMA ="DataBaseName" AND
table_name = "payments";
SET NEW.`payment_code` = CONCAT("sahf4d2fdd45",#xId);
END;
"DataBaseName" is the name of our Data Base
Simple query would do
SHOW TABLE STATUS LIKE 'table_name'
For MySQL 8 use SHOW CREATE TABLE to retrieve the next autoincrement insert id:
SHOW CREATE TABLE mysql.time_zone
Result:
CREATE TABLE `time_zone` (
`Time_zone_id` int unsigned NOT NULL AUTO_INCREMENT,
`Use_leap_seconds` enum('Y','N') CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT 'N',
PRIMARY KEY (`Time_zone_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1784 DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 ROW_FORMAT=DYNAMIC COMMENT='Time zones'
See the AUTO_INCREMENT=1784 at the last line of returned query.
Compare with the last value inserted:
select max(Time_zone_id) from mysql.time_zone
Result:
+-------------------+
| max(Time_zone_id) |
+-------------------+
| 1783 |
+-------------------+
Tested on MySQL v8.0.20.
SELECT id FROM `table` ORDER BY id DESC LIMIT 1
Although I doubt in its productiveness but it's 100% reliable
You have to connect to MySQL and select a database before you can do this
$table_name = "myTable";
$query = mysql_query("SHOW TABLE STATUS WHERE name='$table_name'");
$row = mysql_fetch_array($query);
$next_inc_value = $row["AUTO_INCREMENT"];
I suggest to rethink what you are doing. I never experienced one single use case where that special knowledge is required. The next id is a very special implementation detail and I wouldn't count on getting it is ACID safe.
Make one simple transaction which updates your inserted row with the last id:
BEGIN;
INSERT INTO payments (date, item, method)
VALUES (NOW(), '1 Month', 'paypal');
UPDATE payments SET payment_code = CONCAT("sahf4d2fdd45", LAST_INSERT_ID())
WHERE id = LAST_INSERT_ID();
COMMIT;
You can't use the ID while inserting, neither do you need it. MySQL does not even know the ID when you are inserting that record. You could just save "sahf4d2fdd45" in the payment_code table and use id and payment_code later on.
If you really need your payment_code to have the ID in it then UPDATE the row after the insert to add the ID.
What do you need the next incremental ID for?
MySQL only allows one auto-increment field per table and it must also be the primary key to guarantee uniqueness.
Note that when you get the next insert ID it may not be available when you use it since the value you have is only within the scope of that transaction. Therefore depending on the load on your database, that value may be already used by the time the next request comes in.
I would suggest that you review your design to ensure that you do not need to know which auto-increment value to assign next
use "mysql_insert_id()". mysql_insert_id() acts on the last performed query, be sure to call mysql_insert_id() immediately after the query that generates the value.
Below are the example of use:
<?php
$link = mysql_connect('localhost', 'username', 'password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('mydb');
mysql_query("INSERT INTO mytable VALUES('','value')");
printf("Last inserted record has id %d\n", mysql_insert_id());
?>
I hope above example is useful.
If return no correct AUTO_INCREMENT, try it:
ANALYZE TABLE `my_table`;
SELECT AUTO_INCREMENT FROM information_schema.TABLES WHERE (TABLE_NAME = 'my_table');
This clear cache for table, in BD
using the answer of ravi404:
CREATE FUNCTION `getAutoincrementalNextVal`(`TableName` VARCHAR(50))
RETURNS BIGINT
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
DECLARE Value BIGINT;
SELECT
AUTO_INCREMENT INTO Value
FROM
information_schema.tables
WHERE
table_name = TableName AND
table_schema = DATABASE();
RETURN Value;
END
using in your insert query, to create a SHA1 Hash. ex.:
INSERT INTO
document (Code, Title, Body)
VALUES (
sha1( getAutoincrementalNextval ('document') ),
'Title',
'Body'
);
Improvement of #ravi404, in case your autoincrement offset IS NOT 1 :
SELECT (`auto_increment`-1) + IFNULL(##auto_increment_offset,1)
FROM INFORMATION_SCHEMA.TABLES
WHERE table_name = your_table_name
AND table_schema = DATABASE( );
(auto_increment-1) : db engine seems to alwaus consider an offset of 1. So you need to ditch this assumption, then add the optional value of ##auto_increment_offset, or default to 1 : IFNULL(##auto_increment_offset,1)
For me it works, and looks simple:
$auto_inc_db = mysql_query("SELECT * FROM my_table_name ORDER BY id ASC ");
while($auto_inc_result = mysql_fetch_array($auto_inc_db))
{
$last_id = $auto_inc_result['id'];
}
$next_id = ($last_id+1);
echo $next_id;//this is the new id, if auto increment is on
SELECT AUTO_INCREMENT AS next_id FROM information_schema.tables WHERE table_name = 'table name' AND table_schema = 'database name of table name'
mysql_insert_id();
That's it :)
I have a database of Users and another table for Teachers. Teachers have all the properties as a user but also an e-mail address. When inserting into the DB how can I insert the info, ensuring that the ID is the same for both?
the ID currently is on automatic incrament.
this is what I have at the moment:
$sqlQuery="INSERT INTO user(firstName,lastName,DOB,title,password,classRoomID)
VALUES('$myFirstName','$myLastName','$myDOB','$myTitle','$newPassword','$myClassRoom')";
$result=mysql_query($sqlQuery);
$sqlQuery = "INSERT INTO teacher(email) VALUES ('$myEmail')";
$result=mysql_query($sqlQuery);
thank you!
use MYSQL function LAST_INSERT_ID()
OR php mysql http://ro1.php.net/manual/en/function.mysql-insert-id.php
why to use separate table for teachers. instead, you can have email field with in user table and additional field with flag (T ( for teacher) and U (for user). Default can be a U. This have following Pros.
Will Not increase table size as email would be varchar
Remove extra overhead of maintaining two tables.
Same Id can be used
If you want to have that as separate table then answer you selected is good one but make sure last insert id is called in same connection call.
After the first insert, fetch the last inserted id:
$last_id = mysqli_insert_id(); // or mysql_insert_id() if you're using old code
Or you could expand your second query and use mysql's integrated LAST_INSERT_ID() function:
$sqlQuery = "INSERT INTO teacher(id, email) VALUES ((SELECT LAST_INSERT_ID()), '$myEmail')";
Try this:
$sqlQuery="INSERT INTO user(firstName,lastName,DOB,title,password,classRoomID)
VALUES('$myFirstName','$myLastName','$myDOB','$myTitle','$newPassword','$myClassRoom')";
$result=mysql_query($sqlQuery);
$id = mysql_insert_id();
$sqlQuery = "INSERT INTO teacher(id, email) VALUES (' $id ','$myEmail')";
$result=mysql_query($sqlQuery);
Insert data into two tables & using the same ID
First method
$sqlQuery1 = "INSERT INTO user(firstName,lastName,DOB,title,password,classRoomID) VALUES('$myFirstName','$myLastName','$myDOB','$myTitle','$newPassword','$myClassRoom')";
$result1 = mysqli_query($conn, $sqlQuery1);
$lastID = mysqli_insert_id($conn);
$sqlQuery2 = "INSERT INTO teacher(email, lastID) VALUES ('$myEmail', 'lastID')";
$result2 = mysqli_query($conn, $sqlQuery2);
If the first method not work then this is the second method for you
$sqlQuery1 = "INSERT INTO user(firstName,lastName,DOB,title,password,classRoomID) VALUES('$myFirstName','$myLastName','$myDOB','$myTitle','$newPassword','$myClassRoom')";
$result1 = mysqli_query($sqlQuery1);
$sqlQuery2 = "INSERT INTO teacher(email) VALUES ('$myEmail')";
$result2 = mysqli_query($sqlQuery2);
You can set the Foreign Key in your database table (phpMyAdmin/ MySQL Workbench) to let the Foreign Key follow the Primary Key (ID). Then the data after insert will auto-follow the Primary Key ID.
Example here,
Teachers table set ID - Primary Key
Users table set UserID - Foreign Key (will follow the Teachers table ID)
if you're using MySQL WorkBench, you can refer to this link to set a foreign key.
https://dev.mysql.com/doc/workbench/en/wb-table-editor-foreign-keys-tab.html
Hope I can help any of you.
Though you can use the LAST_INSERT_ID() function in order to get the last insert id, the best approach in this case is to create a column reference to user id table.
teacher
id | user_id | email
So the teacher.id could be anyting, but the user_id column is the real reference to user table.
If you use InnoDB table, you can make the database consistent using Foreign keys
You Should Use A Transaction In MySQL. First insert In One Table And GET LAST_INSERT_ID().
Insert LAST_INSERT_ID() In Second Table.
$sqlQuery="INSERT INTO user(firstName,lastName,DOB,title,password,classRoomID)
VALUES('$myFirstName','$myLastName','$myDOB','$myTitle','$newPassword','$myClassRoom')";
$sqlQuery = "INSERT INTO teacher(LAST_INSERT_ID(), email) VALUES (' $id ','$myEmail')";
$result=mysql_query($sqlQuery);
I don't know if it can be done with just a sql query or it needs a php code
when a cid is missing
There exist many missing values which I can't handle manually
For example, here I don't have cid=1 and cid=6.
I want to insert a row:
cid=1 tcp_sport='undefined' tcp_dport='undefined'
and
cid=6 tcp_sport='undefined' tcp_dport='undefined'
It seems to me I should create a procedure and insert between lines
another solution that I thaught was that I will create a table with cid and undifined values with the respective order and then join this one with that one and this join should have for example ifnull(tcp_sport,'')
would you please help me?
First, use MAX for get the largest ID.
SELECT MAX(cid) as max FROM table
Then, create a for loop for checking if the individual IDs exist:
for ($i = 0; $i < $max; $i++) {
// $query = ... SELECT 1 FROM table WHERE cid = $i ...
// check if the number of rows for $query is greater than 0
// if not, INSERT INTO table VALUES ($i, DEFAULT, DEFAULT)
}
The whole idea of an auto increment ID is to have a value that only refers to one thing ever. By "inserting between the lines" you may be opening yourself up to a lot of unforeseen problems. Image you have another table that has some values that link to the CID of this table. What if that table already has an entry for CID=1, When you insert a new item with CID=1 it will then join to that supporting record. So Data that really belongs to the original item with CID=1 will show for the new item which it probably has nothing to do with.
You aren't going to run out of ID values (if you are approaching the limit of integer, switch it to bigInt), don't re-use IDs if you can avoid it.
You need to use PHP to automate this.
<?php
$link = mysql_connect("localhost", "mysql_user", "mysql_password");
mysql_select_db("database", $link);
while($i < max_value_cid)//replace max_value_cid by the numeric maximum value of cid (SELECT MAX(cid) as max FROM table)
{
$result = mysql_query("SELECT * FROM `table` WHERE cid=".$i, $link);
if(mysql_num_rows($result) == 0)
mysql_query("INSERT INTO `table` VALUES ($i, NULL, NULL);", $link);
$i++;
}
?>
Do test the query on a sample set before execution and remember to backup the entire table, just-in-case.
How do I lock mysql tables in php? I currently have this code:
$db->query("LOCK TABLES tbl_othercharge WRITE");
for($x=0;$x<=500; $x++){
$id = get_max();
$db->query("INSERT INTO tbl_othercharge SET tblocID = '$id', assessmentID='lock1'");
}
$db->query("UNLOCK TABLES");
Here's the get_max() function, which obviously will fail if the script above executes simultaneously.
<?php
function get_max(){
global $db;
$max = $db->get_var("SELECT MAX(tblocNumber) FROM tbl_othercharge");
if($max == null){
$max = 1;
}else if($max >= 1){
$max = $max + 1;
}
return 'OC'.$max;
}
?>
I'm trying to test if there are still concurrency problems by executing the same script on 2 browsers.
The script above inserts 400+ records instead of 999 records. How do I properly lock the table while I'm inserting something into it.
I want to lock the table to prevent something like this to happen:
As you can see the field with the prefix 'OC' on it should have a number which is equal to the auto-increment primary key.
The only reliable solution is to do an insert with a dummy value, getting the last insert id, and updating the row to the correct value.
mysql_query("INSERT INTO table (field) VALUES (dummy);");
$id = mysql_last_insert_id();
mysql_query("UPDATE table SET field='OC{$id}' WHERE id={$id} LIMIT 1;");
I'd suggest to drop the 'OC' field from the table, e.g.
CREATE TABLE tbl_othercharge (tblocID int AUTO_INCREMENT PRIMARY KEY, assessmentID varchar(100));
CREATE VIEW vw_othercharge SELECT tblocID, concat('OC',tblocID) as OCnumber, assessmentID FROM tbl_othercharge
now direct all relevant SELECTs to vw_othercharge and forget about it.
Have you try:
for($x=0;$x<=500; $x++){
$db->query("LOCK TABLES tbl_othercharge WRITE");
$id = get_max();
$db->query("INSERT INTO tbl_othercharge SET tblocID = '$id', assessmentID='lock1'");
$db->query("UNLOCK TABLES");
}
In this way you will set lock each time you insert a row!
I'm new to php. So, please forgive me if this seems like a dumb question.
Say i have a MySQL insert statement insert into table (a,b) values (1,2),(3,4),(5,6). table 'table' has a auto increment field called 'id'.
how can I retrieve all the ids created by the insert statement above?
It will be great if i get an example that uses mysqli.
You can't. I would suggest that you maintain your own ids (using guid or your own auto-increment table) and use it when you insert into the table.
But it's possible to get the auto-increment value for the last inserted using LAST_INSERT_ID():
http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html
AngeDeLaMort's answer is almost right. Certainly, the most appropriate way to deal with the problem is to insert one row at a time and poll the insert_id or generate the sequence elsewhere (which has additional benefits in terms of scalability).
I'd advise strongly against trying to determine the last insert_id and comparing this the most recent insert_id after the insert - there's just too may ways this will fail.
But...an alternative approach would be:
....
"INSERT INTO destn (id, data, other, trans_ref)
SELECT id, data, other, connection_id() FROM source";
....
"SELECT id FROM destn WHERE trans_ref=connection_id()";
....
"UPDATE destn SET trans_ref=NULL where trans_ref=connection_id()";
The second query will return the ids generated (note that this assumes that you use the same connection for all 3 queries). The third query is necessary because connection ids to go back into the pool when you disconnect (i.e. are reused).
C.
In some cases, if you have another identifier of sort such as a UserID, you could filter your query by UniqueID's greater than or equal to mysql_insert_id(), limit by the number of affected rows and only display those by the user. This would really only work inside of a transaction.
$SQL = "INSERT INTO Table
(UserID, Data)
VALUES
(1,'Foo'),
(1,'Bar'),
(1,'FooBar')";
$Result = mysql_query($SQL);
$LastID = mysql_insert_id();
$RowsAffected = mysql_affected_rows();
$IDSQL = "SELECT RecordID
FROM Table
WHERE UserID = 1
AND RecordID >= '$LastID'
LIMIT '$RowsAffected'";
$IDResult = mysql_query($IDSQL);
as a follow up to AngeDeLaMort:
You could seperate your inserts and do it something like this:
$data = array (
array(1,2),
array(3,4),
array(5,6)
);
$ids = array();
foreach ($data as $item) {
$sql = 'insert into table (a,b) values ('.$item[0].','.$item[1].')';
mysql_query ($sql);
$id[] = mysql_insert_id();
}
Now all your new id's are in the $id array.
Maybe I can do this
$insert = "insert into table (a,b) values (1,2),(3,4),(5,6)";
$mysqli->query($insert);
$rows_to_be_inserted=3;
$inserted_id = $mysqli->insert_id // gives me the id of the first row in my list
$last_row_id = ($inserted_id+$rows_to_be_inserted)-1;
$mysql->query("select * from table where id between $inserted_id and $last_row_id");
what to you guys say?