How MySQL lets the self ID set the method starting from 1

Like what:

The code is as follows	Copy Code
TRUNCATE TABLE table1

TRUNCATE table table1 (table name) or this can also be:

The code is as follows	Copy Code
ALTER TABLE table_name AUTO

Method Two

Will not empty the existing data, the operation is more flexible, not only can return to zero, but also for the deletion of a large number of consecutive rows, reset the value and insert new data, or starting from the new value, of course, can not and existing conflicts.

The code is as follows	Copy Code
$sql = "Delete from $table _vote"; mysql_query ($sql, $link); $sql = "ALTER TABLE $table _vote auto_increment=1"; mysql_query ($sql, $link);

MySQL Database unique number field (AutoNumber field)
In database applications, we often use a unique number to identify the record. Auto_increment Properties of data columns available in MySQL

From dynamic generation. MySQL supports a variety of data tables, each of which has a different properties of the data table, which will introduce the data in various tables

Column self-increasing property.

ISAM table

If you insert a null into a auto_increment data column, MySQL automatically generates the next sequence number. Number is open from 1

Beginning, and 1 for cardinality increment.

The effect of inserting 0 into a auto_increment data column is the same as inserting a null value. This is not recommended, however, or it is better to insert a null value.

When you insert a record without explicitly specifying a value for Auto_increment, the equivalent is to insert a null value.

When you insert a record, if you explicitly specify a numeric value for the auto_increment data column, there are two situations where, if

The inserted value repeats with the existing number, and an error message occurs because the value of the Auto_increment data column must be unique;