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I answedred a question like this back in April 2012 : http://dba.stackexchange.com/questions/16847/how-can-you-have-two-auto-incremental-columns-in-one-table/16849#16849How can you have two auto-incremental columns in one table? You need to create one table whose sole purpose is the create sequences of work order for each site

I answedred a question like this back in April 2012 : http://dba.stackexchange.com/questions/16847/how-can-you-have-two-auto-incremental-columns-in-one-table/16849#16849 You need to create one table whose sole purpose is the create sequences of work order for each site

I answedred a question like this back in April 2012 : How can you have two auto-incremental columns in one table? You need to create one table whose sole purpose is the create sequences of work order for each site

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I answedred a question like this back in April 2012 : http://dba.stackexchange.com/questions/16847/how-can-you-have-two-auto-incremental-columns-in-one-table/16849#16849 You need to create one table whose sole purpose is the create sequences of work order for each site

CREATE TABLE site_workorder_seq
(
    SiteID int not null,
    SiteWorkorderNum int not null auto_increment,
    PRIMARY KEY (SiteID,SiteWorkorderNum)
); ENGINE=MyISAM;

You need to create one table whose sole purpose is the create sequences of work order for each site

CREATE TABLE site_workorder_seq
(
    SiteID int not null,
    SiteWorkorderNum int not null auto_increment,
    PRIMARY KEY (SiteID,SiteWorkorderNum)
);

I answedred a question like this back in April 2012 : http://dba.stackexchange.com/questions/16847/how-can-you-have-two-auto-incremental-columns-in-one-table/16849#16849 You need to create one table whose sole purpose is the create sequences of work order for each site

CREATE TABLE site_workorder_seq
(
    SiteID int not null,
    SiteWorkorderNum int not null auto_increment,
    PRIMARY KEY (SiteID,SiteWorkorderNum)
) ENGINE=MyISAM;
1
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What is interesting about this situation can be solved using the MyISAM storage.

You need to create one table whose sole purpose is the create sequences of work order for each site

CREATE TABLE site_workorder_seq
(
    SiteID int not null,
    SiteWorkorderNum int not null auto_increment,
    PRIMARY KEY (SiteID,SiteWorkorderNum)
);

Here is a sample loading into this table:

mysql>     DROP DATABASE david;
Query OK, 1 row affected (0.01 sec)

mysql>     CREATE DATABASE david;
Query OK, 1 row affected (0.00 sec)

mysql>     USE david
Database changed
mysql>     CREATE TABLE site_workorder_seq
    ->     (
    ->         SiteID int not null,
    ->         SiteWorkorderNum int not null auto_increment,
    ->         PRIMARY KEY (SiteID,SiteWorkorderNum)
    ->     ) ENGINE=MyISAM;
Query OK, 0 rows affected (0.01 sec)

mysql>     INSERT INTO site_workorder_seq (SiteID) VALUES
    ->     (1),(1),(2),(3),(3),(3),(3),(4),(4),(4),
    ->     (5),(5),(4),(2),(2),(2);
Query OK, 16 rows affected (0.00 sec)
Records: 16  Duplicates: 0  Warnings: 0

mysql>     SELECT * FROM site_workorder_seq;
+--------+------------------+
| SiteID | SiteWorkorderNum |
+--------+------------------+
|      1 |                1 |
|      1 |                2 |
|      2 |                1 |
|      2 |                2 |
|      2 |                3 |
|      2 |                4 |
|      3 |                1 |
|      3 |                2 |
|      3 |                3 |
|      3 |                4 |
|      4 |                1 |
|      4 |                2 |
|      4 |                3 |
|      4 |                4 |
|      5 |                1 |
|      5 |                2 |
+--------+------------------+
16 rows in set (0.00 sec)

mysql>

Let's look at the the last WorkorderNum from each site

mysql> SELECT SiteID,MAX(SiteWorkorderNum) SiteWorkorderNum
    -> FROM site_workorder_seq GROUP BY SiteID;
+--------+------------------+
| SiteID | SiteWorkorderNum |
+--------+------------------+
|      1 |                2 |
|      2 |                4 |
|      3 |                4 |
|      4 |                4 |
|      5 |                2 |
+--------+------------------+
5 rows in set (0.05 sec)

mysql>

Now, suppose you want to get the next SiteWorkorderNum for SiteID 3. You could do this:

INSERT INTO site_workorder_seq (SiteID) VALUES (3);
SELECT MAX(SiteWorkorderNum) INTO @nextworkordernum
FROM site_workorder_seq WHERE SiteID=3;
SELECT @nextworkordernum;

Let's run this and see what happens

mysql> INSERT INTO site_workorder_seq (SiteID) VALUES (3);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT MAX(SiteWorkorderNum) INTO @nextworkordernum
    -> FROM site_workorder_seq WHERE SiteID=3;
Query OK, 1 row affected (0.00 sec)

mysql> SELECT @nextworkordernum;
+-------------------+
| @nextworkordernum |
+-------------------+
|                 5 |
+-------------------+
1 row in set (0.03 sec)

mysql> SELECT * FROM site_workorder_seq;
+--------+------------------+
| SiteID | SiteWorkorderNum |
+--------+------------------+
|      1 |                1 |
|      1 |                2 |
|      2 |                1 |
|      2 |                2 |
|      2 |                3 |
|      2 |                4 |
|      3 |                1 |
|      3 |                2 |
|      3 |                3 |
|      3 |                4 |
|      3 |                5 |
|      4 |                1 |
|      4 |                2 |
|      4 |                3 |
|      4 |                4 |
|      5 |                1 |
|      5 |                2 |
+--------+------------------+
17 rows in set (0.00 sec)

mysql> SELECT SiteID,MAX(SiteWorkorderNum) SiteWorkorderNum
    -> FROM site_workorder_seq GROUP BY SiteID;
+--------+------------------+
| SiteID | SiteWorkorderNum |
+--------+------------------+
|      1 |                2 |
|      2 |                4 |
|      3 |                5 |
|      4 |                4 |
|      5 |                2 |
+--------+------------------+
5 rows in set (0.00 sec)

mysql>

As long as you use this one MyISAM apart from all InnoDB tables, you can generate workordernums per site to your hearts content.