MySQL serial number generator)

If you do not want to use MySQL auto-increment, but want to implement the primary key serial number function, you can use the following method to maintain the serial number of multiple tables using a function, simple and practical

1. Create a Data Maintenance table that generates the serial numbers of multiple tables

Create Table seq (
Name varchar (20) not null,
Val int (10) unsigned not null,
Primary Key (name)
) Engine = MyISAM default charset = UTF-8

2. Insert several initialization data entries

Insert into seq values ('one', 100 );
Insert into seq values ('two', 1000 );

3. Create a function to generate a serial number

Create Function seq (seq_name char (20) returns int
Begin
Update seq set val = last_insert_id (Val + 1) Where name = seq_name;
Return last_insert_id ();
End

4. Test

2. Mysql>SelectSeq('One'), Seq('Two'), Seq('One'), Seq('One');
4. +------------ +
6. | Seq('One')| Seq('Two')| Seq('One')| Seq('One')|
8. +------------ +
10. |102|1002|103|104|
12. +------------ +
14. 1RowIn Set (0.00Sec)