MYSQL > Autoincrement-Problem - Printable Version

MYSQL > Autoincrement-Problem - Printable Version

+- SA-MP Forums Archive (https://sampforum.blast.hk)
+-- Forum: SA-MP Scripting and Plugins (https://sampforum.blast.hk/forumdisplay.php?fid=8)
+--- Forum: Scripting Help (https://sampforum.blast.hk/forumdisplay.php?fid=12)
+--- Thread: MYSQL > Autoincrement-Problem (/showthread.php?tid=577772)

MYSQL > Autoincrement-Problem - Meisternuke - 14.06.2015

How can i get the next ID that will be created in my Database for a autoincrement field?
Example:

id | name
1 | a
2 | b
3 | c

I delete 2 + 3
next ID would be 4

how do i get the ID 4 to use it in a string:
printf("The next ID is: 4, want to insert?",nextID);

Mysql from BlueG

Re: MYSQL > Autoincrement-Problem - [KHK]Khalid - 14.06.2015

Hmm, save the last deleted ID in some variable and just add one to it to figure out next ID. It's just a quick thinking, check this example maybe:

pawn Код:

// When deleting for example ID 5
lastDeletedID = 5;
// Then somewhere else
printf("The next ID will be: %d, want to insert?", lastDeletedID + 1);

Edit:

I think you should add to my code to check if the deleted ID is highest or not.

Re: MYSQL > Autoincrement-Problem - Meisternuke - 14.06.2015

ok, but this only works during the server runing without any restart
when i restart, the id would be anyways id:4
but there is no deleted item everytime

Re: MYSQL > Autoincrement-Problem - [KHK]Khalid - 14.06.2015

You can save last deleted ID somewhere (your database) I think. Also, check my edit in my first post, it's important.

Re: MYSQL > Autoincrement-Problem - Emmet_ - 14.06.2015

There is a built-in function in MySQL for this. Try something like:

pawn Код:

SELECT MAX(column_name) + 1 FROM `table_name`

Re: MYSQL > Autoincrement-Problem - Meisternuke - 14.06.2015

Like:

stock getLastID()
{
mysql_query(sqlConnection,"SELECT MAX(gID) + 1 FROM `gangzones`");
lastZoneGIDDatabase = cache_get_field_content_int(0,"MAX(gID)");
return 1;
}

Re: MYSQL > Autoincrement-Problem - Emmet_ - 14.06.2015

MySQL uses threaded queries so unfortunately you can't do that. You'll have to pass it through a callback and do it that way.

pawn Код:

mysql_query(sqlConnection, "SELECT MAX(gID) + 1 FROM `gangzones`", "onGetLastID");

pawn Код:

forward onGetLastID();
public onGetLastID() {
    lastZoneGIDDatabase = cache_get_row_int(0, 0);
}

Re: MYSQL > Autoincrement-Problem - Konstantinos - 14.06.2015

Quote:

Originally Posted by Emmet_

MySQL uses threaded queries so unfortunately you can't do that. You'll have to pass it through a callback and do it that way.

pawn Код:

mysql_query(sqlConnection, "SELECT MAX(gID) + 1 FROM `gangzones`", "onGetLastID");

pawn Код:

forward onGetLastID();
public onGetLastID() {
    lastZoneGIDDatabase = cache_get_row_int(0, 0);
}

Not quite accurate because if a row is deleted, it will return the last existed gID + 1 and an INSERT statement would give a different value than that.