I have a MySql table which consists a field serial_no. I want that, when a new row is being inserted, it should set the serial_no field as next of previous maximum of serial_no.
Lets say, previous max of serial_no is 10, then the new row will be inserted with serial_no 11.
Below is how do I currently manage this.
$max_ser = mysql_query("SELECT MAX(serial)+1 as next_ser FROM widgets WHERE position='".$position."'");
if($max_ser){
$row_ser = mysql_fetch_array($max_ser);
}
$insert = 'INSERT INTO widgets(widget_name, widget_alias, widget_type, position, publish_to, serial, status)
VALUES("'.$name.'", "'.$alias.'", "'.$type.'", "'.$position.'", "'.$menus.'", "'.$row_ser['next_ser'].'", "'.$status.'")';
Can it be done in MySql with a single statement?
Any help is appreciated.
Thanks.
I think you are looking for MySql's AUTO_INCREMENT attribute.
If you want to specify your starting point to another number, use:
ALTER TABLE <YOUR_TABLE> AUTO_INCREMENT = 999
Related
I used INSERT INTO SELECT to copy values (multiple rows) from one table to another. Now, my problem is how do I insert rows with its corresponding IDs from different tables (since it's normalized) into a gerund table because it only outputs one row in my gerund table. What should I do to insert multiple rows and their corresponding IDs in the gerund table.
My code for the gerund table goes like this.
$insert = "INSERT INTO table1 SELECT * FROM sourcetable"; // where id1 is pk of table1.
$result =mysqli_query($conn,$insert)
$id1=mysqli_insert_id($conn);
Now table 1 has inserted multiple rows same as the other 2 tables.
Assuming id.. are the foreign keys
INSERT INTO gerundtable (pk, id1,id2,id3) VALUES ($id1,$id2,$id3);
My problem is it doesn't yield multiple rows.
According to MySql documentation:
For a multiple-row insert, LAST_INSERT_ID() and mysql_insert_id() actually return the AUTO_INCREMENT key from the first of the inserted rows. This enables multiple-row inserts to be reproduced correctly on other servers in a replication setup.
So, grab the number of records being copied, and the LAST_INSERT_ID() and you should be able to map exact IDs with each copied row.
In the lines of:
$mysqli->query("Insert Into dest_table Select * from source_table");
$n = $mysqli->affected_rows; // number of copied rows
$id1 = $mysqli->insert_id; // new ID of the first copied row
$id2 = $mysqli->insert_id + 1; // new ID of the second copied row
$id3 = $mysqli->insert_id + 2; // new ID of the third copied row
...
$mysqli->query("INSERT INTO gerundtable (pk, id1,id2,id3) VALUES ($id1,$id2,$id3)");
Thank you for trying to understand and also answering my question. I resolved my own code. I used while loop to get the ids of every row and didn't use INSERT INTO SELECT.
Here is the run down. SInce I'm just using my phone bare with my way posting.
$sqlselect = SELECT * FROM table1;
While($row=mysqli_fetch_array(table1){
$insertquery...
$id1=mysqli_insert_id($conn)
$insertgerundtable = INSERT INTO gerundtable VALUES ( $id1, $id2);
}
Okay so this is my first question and I really have no idea how to ask it so I'm going to try and be as specific as possible. My website is an online game and for user inventories when it inserts a new item into the database
Table name "inventory"
Column names "inv_id", "inv_itemid", "inv_userid", "inv_qty"
and it does not add to the column inv_qty and populate properly instead it creates a new inv_id identifier and row for each item. I was wondering if there was a way for me to create a merge function via php to merge all items with the same inv_itemid and inv_userid while adding to the inv_qty colum and populating the inv_id
In my inventory.php file the inv_id column is used to let the user either equip the item or use it as the main variable.
I have seen this done and have tried many times and I just can't get it to work.
If it were a single key to check then you could have used 'ON DUPLICATE KEY UPDATE' of mysql like the following:
INSERT INTO table(field1, field2, field3, ..)
VALUES (val1, val2, val3, ...)
ON DUPLICATE KEY
UPDATE field3='*'
But in your case there is a combination to consider.
If "inv_id", "inv_itemid", "inv_userid" mathces then UPDATE, otherwise INSERT.
One way to achieve this using only mysql in a single query is to create & use a Stored Procedure.
But using php you can achieve this in 2 query. First query is to determine if the combination exists. Then based on this run the next Insert or Update query.
Please check the following example:
$sql1 = SELECT * FROM inventory WHERE inv_id='$inv_id', inv_itemid='$inv_itemid', inv_userid='$inv_userid'
// Execute $sql1 and get the result.
IF result empty, then INSERT:
$sql2 = INSERT INTO inventory ....
otherwise UPDATE.
$sql2 = UPDATE inventory SET inv_qty=(inv_qty + $update_qty) WHERE inv_id='$inv_id', inv_itemid='$inv_itemid', inv_userid='$inv_userid'
About:
Would there be a way to write a php function at the top of the inventory page for my users to click to merge them
Please check with the following php function.
By calling with param: UserID, it will create a new entry with sum of the inv_qty, for each (inv_itemid + inv_userid) combination and removes the previous duplicate entries of (inv_itemid + inv_userid) leaving the newly enterd: (inv_itemid + inv_userid + (SUM of inv_qty)).
Important, please keep a back up of the DB Table Data before running the function.
Please check the comments in the function and update where necessary based on your system, Like getting the last inserted inv_id.
function merger_fnc($user_id) {
// For Each Combination of: inv_itemid + inv_userid
// This function will Insert a new row in the inventory with the SUM of inv_qty
// And then will remove the previous single rows of: inv_itemid + inv_userid + inv_qty
// First get the distinct Items of the User(by UserID);
$inv_itemids = $db->query("SELECT DISTINCT(inv_itemid) FROM inventory WHERE inv_userid=".$user_id);
// Here $inv_itemids will hold all the distinct ItemIDs for the UserID;
foreach ($inv_itemids as $inv_item) {
// We will Insert A new row which will have the sum of 'inv_qty' for the inv_userid & inv_itemid;
$inv_itemid = $inv_item['inv_itemid'];
// I am not sure what type of result set your $db->query(...) returns. So I assumed it is associative array.
// If the result is an Array of objects, then please use: $inv_itemid = $inv_item->inv_itemid;
$insert_sql = "INSERT INTO inventory (inv_itemid, inv_userid, inv_qty) VALUES ('".$inv_itemid."', '".$user_id."', (SELECT SUM(inv_qty) FROM FROM inventory WHERE inv_userid=".$user_id."))";
$inv_itemids = $db->query($insert_sql);
$inserted_new_inventory_id = $db->insert_id;
// Please check the appropriate method for it in your $db class here.
// In mysqli, it is: mysqli_insert_id($db_conn); In PDO it is: $db_conn->lastInsertId();
// Last we remove the previous data of combination(inv_userid & inv_itemid) but leaving our last inserted row.
$delete_sql = "DELETE FROM inventory WHERE inv_id!='".$inserted_new_inventory_id."' AND inv_userid='".$user_id."' AND inv_itemid='".$inv_itemid."'";
$db->query($delete_sql);
}
}
If getting the last inserted inv_id is troublesome from $db(like inv_id is not defined as key in the table), you can try another approach:
Do another query and save the previous inv_id in an array, before the insertion.
After the insertion of the new entry with sum of qty, run a delete query to delete the previous single qty entries, like the following:
DELETE FROM inventory WHERE inv_id IN (3, 4, 7,...)
Here (3, 4, 7,...) are the previous inv_id for (inv_itemid + inv_userid) combination.
I am trying to update "new" column value with new value but problem is my query remove previous data while inserting new value
What is want: here is example table structure,
Table name = agg_lvl primary key set = uid
uid | new
--------|--------
1 | 100
2 | 300
You can see "new" has 100 points, for example I send 100 new points to user 1, so new column value should be 100 + 100 = 200, right now with this code
$query4 = mysql_query("INSERT INTO agg_lvl (uid, new) VALUES ('$uid','$new')
ON DUPLICATE KEY UPDATE uid='$uid',new='$new'");
Not sure what
new = '$new'
I have tried both ways but no success = >
new = 'new + $new' or new = new + '$new'
You should make changes in your query
Make num = nun+$num to add new value to old one
Remove quotes arount $new because it is a number but not a string
Remove uid from set list because insert already point to that record
And your query should look so:
$query4 = mysql_query("INSERT INTO agg_lvl (uid, new) VALUES ('$uid','$new')
ON DUPLICATE KEY UPDATE new=new+$new");
Okay first i will answer with the proper way to do the same, In this case i am assuming that UID is unique, so you make a new table scorecard with UID as foreign key. Now rather than update, you just insert stuff to table like if UID 1 gains 10 and 20 points, there are two entries. onw with 10 and one with 20. Now to get his current points, you add all points where UID=1 .
Now in your implementation the correct query would be
UPDATE userData SET points = points + x WHERE UID = $uid
where x is the new points gained and points is the name of column
$query4 = mysql_query("INSERT INTO agg_lvl (uid, new) VALUES ('$uid','$new')
ON DUPLICATE KEY UPDATE uid='$uid',new=new+$new");
worked for me with help of #splash58
Following is my database in mysql:
Id Username Password
1 admin admin
2 jay jay1
3 suman xyza
4 chintan abcde
This is my code in php:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
$user= $_POST['username'];
$pass= $_POST['password'];
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."'
);");
Problem:
Now if I delete row with Id=1 and then re-enter the data then it should use ID=1 then Again I reinsert the data it use ID=5
It works like this:
if I delete row with Id=1 and then re-enter the data the Id it gets is 5 but then 1 is free so,
What should I write to perform that task.
First, if you set your Id column to AUTO_INCREMENT you don't need the following part in your code at all:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
Because AUTO_INCREMENT will automatic add new value to your ID colume.
But if you don't set it to AUTO_INCREMENT, the above code will grab the MAXIMUM ID value (in this case, 4).
When you re-enter your data again after you delete the row 1, the MAXIMUM ID still 4, so your new ID value will be 5 (from $largest++;).
.....
If you really need to use consecutive ids as you PK, you need to re-write you code but I suggest you to use UUID for you ID column instead.
You can easily generate UUID by using uuid().
How about the UUID performance? Refer to Dancrumb's answer about this:
A UUID is a Universally Unique ID. It's the universally part that you should be considering here.
Do you really need the IDs to be universally unique? If so, then UUIDs
may be your only choice.
I would strongly suggest that if you do use UUIDs, you store them as a
number and not as a string. If you have 50M+ records, then the saving
in storage space will improve your performance (although I couldn't
say by how much).
If your IDs do not need to be universally unique, then I don't think
that you can do much better then just using auto_increment, which
guarantees that IDs will be unique within a table (since the value
will increment each time)
see. UUID performance in MySQL?
EDIT: I don't suggest you run query on the whole table just to find the MAX ID value before inserting new value everytime, because it will give you a performance penalty (Imagine that if you have million rows and must query on them everytime just to insert a new row, how much workload causes to your server).
It is better to do the INSERT just as INSERT, no more than that.
EDIT2:
If you really want to use consecutive ids, then how about this solution?
Create new TABLE just for store the ids for insert (new ids and the ids that you deleted).
For example:
CREATE TABLE cons_ids (
ids INT PRIMARY KEY,
is_marker TINYINT DEFAULT 0
);
then initial ids with values from 1-100 and set marker to be '1' on some position, e.g. 80th of whole table. This 'marker' uses to fill your ids when it's nearly to empty.
When you need to INSERT new Id to your first table, use:
$result = mysql_query("SELECT ids, marker FROM cons_ids ORDER BY ids ASC LIMIT 1;");
$row = mysql_fetch_row($result);
and use $row[0] for the following code:
INSERT INTO yourtable (Id, Username, Password)
VALUES ($row[0], $username, $password);
DELETE FROM cons_ids
WHERE ids = $row[0];
This code will automatically insert the lowest number in cons_ids as your Id and remove it from the cons_ids table. (so next time you do insert, it will be the next lowest number)
Then following with this code:
if ($row[1] == 1) {
//add new 100 ids start from the highest ids number in cons_ids table
//and set new marker to 80th position again
}
Now each time you delete a row from your first table, you just add the Id from the row that you deleted to cons_ids, and when you do INSERT again, it will use the Id number that you just deleted.
For example: your current ids in cons_ids is 46-150 and you delete row with Id = 14 from first table, this 14 will add to your cons_ids and the value will become 14, and 46-150. So next time you do INSERT to your first table, your Id will be 14!!.
Hope my little trick will help you solve your problem :)
P.S. This is just an example, you can modify it to improve its performance.
First of all, as I understand, you are selecting highest column ID which should be always the last one (since you set auto-increment on ID column).
But what are you trying to do is actually filling up holes after delete query, right?
If you are really looking for such approach, try to bypass delete operation by making new boolean column where you flag record if it is active or not (true/false).
SQL table change:
Id Username Password Active
1 admin admin false
2 jay jay1 true
3 suman xyza false
4 chintan abcde true
PHP request:
$fetchid = mysql_query(" SELECT MIN(Id) As min FROM user WHERE active = false;");
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
`Active`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."', 'true'
);");
I have this id number in one column of my table,
0907003
0907004
0907005
1008005
1008006
1008007
1009001
1009002
1009003
When I add new value of 1009, it will add last three number of 004 because the last number begin with 1009 (10-09) is 003.
Or if I add new value of 1008, it will add last three number of 008
because the last number begin with 1008 (10-08) is 007.
Or if I add new value of 0907, it will add last three number of 006
because the last number begin with 0907 (09-07) is 007.
How to do this?
Many thanks in advance!
$front_id = $this->input->post('gameid'); //09
$middle_id = $this->input->post('netid'); //07
//$last_id will be generate automatically by sql
$forID = $front_id.$middle_id;
$sql = "INSERT INTO table ('colum') VALUES (".$forID.")"
You have to insert new id manually
$max_of_letsay1009 = mysql_result(mysql_query("select MAX(id) from table where id like '1009%'"),0);
// get the last 3 digits
$new_number = (int)substr($max_of_letsay1009,-3) + 1;
or you can try this too:
$new_id_of_letsay1009 = mysql_result(mysql_query("select MAX(id)+1 from table where id like '1009%'"),0);
this is just my idea, not yet tested and no error checking
You try this below query
If your value is 1009
SELECT MAX(RIGHT(ID,4))+1 FROM TableName WHERE LEFT(ID,4) = '1009'
It will return the max number of that series.
Try this query for dynamic ID length
SELECT MAX(RIGHT(ID,len(id)-LEN('1009')))+1 FROM #TEMP WHERE LEFT(ID,LEN('1009')) = '1009'
You can also use this query as sub query for the insert statement's ID column.
It is possible if it is not Auto_Increment coulmn.
Just need to write logic on insert time.