I have a query that returns the next auto-increment value (id), and I use that value when I'm inserting data in table t_name.
SELECT AUTO_INCREMENT id
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'db_name'
AND TABLE_NAME = 't_name'
But I want that this query gives a different value each time. E.g. Me and my pal are inserting data in db at same time, so I will get one id, he will get another. When I run this query, I want it to give me a different and incremented value each time.
Is it possible? Or do I have to create tables with sequences?
You can insert and than get the last inserted id:
$connection = mysqli_connect($rv, $username, $pass, $mydatabase);
$result = $connection->query('INSERT INTO mytable (id, name) VALUES("", "myName")');
if($result)
{ $lastId = connection->insert_id;
// so something with $lastId...
}
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 $next_id;//this is the new id, if auto increment is on
SELECT AUTO_INCREMENT AS next_id FROM information_schema.tables WHERE table_name = 'table name' AND table_schema = 'database name of table name'
mysql_insert_id();
That's it :)
I have a table named users
fields:
ID INT
First_name VARCHAR
Second_name VARCHAR
National_ID INT
The ID field is an AUTO_INCREMENT.
I need to AUTO_INCREMENT the first 2000 users with just the ID and the other fields remain blank,so that the new users will start at 2001.
Kindly assist.
It's called auto increment, your ID column must be set to auto increment.
ALTER TABLE users AUTO_INCREMENT=2001;
Update
If you wish to actually create those rows (not just set the auto increment value) you can use PHP for this:
for($i=1; $i<=2000; $i++)
{
$query = 'INSERT INTO users (id) VALUES ('.$i.')';
//execute this query using your desired PDO or sql extension
}
Ok is there a possibility to update a column instead of a row?
f.e something like that:
$laninpstmt = $db->prepare ("UPDATE table SET column_name WHERE id = :allids");
$laninpstmt->bindParam(':allids', $_POST['input0']);
$laninpstmt->bindParam(':allids', $_POST['input1']);
$laninpstmt->bindParam(':allids', $_POST['input2']);
$laninpstmt->bindParam(':allids', $_POST['input3']);
$laninpstmt->bindParam(':allids', $_POST['input3']);
If i explain the code it's like:
Update all the rows(allids) from one column in a table
Running your query without a where clause will update all rows, and if you update a single field it will be the same as updating a column
UPDATE `test` SET `field_5` = 7
Will update table test and set all values in the column field_5 to 7
You could use IN:
Apparently, you need to do your own query, see https://stackoverflow.com/a/920523/2575355.
$inputs = array($_POST['input0'], $_POST['input1'], $_POST['input2']);
$allids = implode(', ', $inputs)
$laninpstmt = $db->prepare ("UPDATE table SET column_name WHERE id IN ($allids)");
You forgot to specify the value for you column_name like that
UPDATE table SET column_name = 'Some_value here' WHERE id = :allids
i guess you want do this
$laninpstmt = $db->prepare ("UPDATE table SET column_name = Concat(:allids1 , :allids2, :allids3, :allids4) WHERE id = :allids");
$laninpstmt->bindParam(':allids', $_POST['input0']);
$laninpstmt->bindParam(':allids1', $_POST['input1']);
$laninpstmt->bindParam(':allids2', $_POST['input2']);
$laninpstmt->bindParam(':allids3', $_POST['input3']);
$laninpstmt->bindParam(':allids4', $_POST['input4']);
I'd like to make a table with row entries that define columns in another Table. This way I can easily update the tables later on if the questions for a form are changed or added.
Eg.
Table1: Questions
Question column_name column_type characters default
What is your name? name Char 255 ''
When where you born? birth char 255 ''
What is today's date? date int ''
Do you have a pet? pet bin 0
Table2: Results
name birth date
Cammy Teaneck 1988
Tommy Tenefly 2001
Tasha Brooklyn 1950
In the php form, check to see if all columns exist, if not create them in table2 and then add entry
$collect = db_query("SELECT column_name FROM {Table1}");
while ($data = db_fetch_array($collect)){
$name = $data['column_name'];
$stretch = db_query("SELECT $name FROM {Table2}");
if ($stretch == null or false){
UPDATE TABLE Table2 ($name $type($char) DEFAULT $default)
}
}
The pseudocode for what you are asking for is as follows:
foreach column in table1 {
$res = query("select column from table2");
if( ! $res ) {
query("alter table add field datatype(size) to table 2");
}
}
Heres a crude implementation, from where I got the idea from:
http://forums.phpfreaks.com/topic/193330-alter-table-add-column-if-not-exists-possible/
Please use information schema in mysql to check
whether this table contain this field or not
you can Find table name in information_schema this
use Like this
SELECT * FROM information_schema.COLUMNS WHERE TABLE_NAME='Table2' and COLUMN_name IN ('name','birth','date')
Please try this