mysql削除トリガー

FOR EACH ROWとの混同が原因だと思いますステートメント。
これは、「トリガーが呼び出される前に発行されたステートメントの一致したレコード」のみです。 "

Nが存在する場合テーブル内のレコードの数であり、where id=xのレコードと一致します、
xを想定 N未満の結果になりますレコード、たとえばN-5 、次に
FOR EACH ROW N-5のループが発生します時間のみ。

更新：
FOR EACH ROWが原因で影響を受けた行で実行されたサンプルテストステートメントを以下に示します。

mysql> -- create a test table
mysql> drop table if exists tbl; create table tbl ( i int, v varchar(10) );
Query OK, 0 rows affected (0.01 sec)

Query OK, 0 rows affected (0.06 sec)

mysql> -- set test data
mysql> insert into tbl values(1,'one'),(2,'two' ),(3,'three'),(10,'ten'),(11,'eleven');
Query OK, 5 rows affected (0.02 sec)
Records: 5  Duplicates: 0  Warnings: 0

mysql> select * from tbl;
+------+--------+
| i    | v      |
+------+--------+
|    1 | one    |
|    2 | two    |
|    3 | three  |
|   10 | ten    |
|   11 | eleven |
+------+--------+
5 rows in set (0.02 sec)

mysql> select count(*) row_count from tbl;
+-----------+
| row_count |
+-----------+
|         5 |
+-----------+
1 row in set (0.00 sec)

mysql>
mysql> -- record loop count of trigger in a table
mysql> drop table if exists rows_affected; create table rows_affected( i int );
Query OK, 0 rows affected (0.02 sec)

Query OK, 0 rows affected (0.05 sec)

mysql> select count(*) 'rows_affected' from rows_affected;
+---------------+
| rows_affected |
+---------------+
|             0 |
+---------------+
1 row in set (0.00 sec)

mysql>
mysql> set @cnt=0;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> -- drop trigger if exists trig_bef_del_on_tbl;
mysql> delimiter //
mysql> create trigger trig_bef_del_on_tbl before delete on tbl
    ->   for each row begin
    ->     set @cnt = if(@cnt is null, 1, (@cnt+1));
    ->
    ->     /* for cross checking save loop count */
    ->     insert into rows_affected values ( @cnt );
    ->   end;
    -> //
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> delimiter ;
mysql>
mysql> -- now let us test the delete operation
mysql> delete from tbl where i like '%1%';
Query OK, 3 rows affected (0.02 sec)

mysql>
mysql> -- now let us see what the loop count was
mysql> select @cnt as 'cnt';
+------+
| cnt  |
+------+
| 3    |
+------+
1 row in set (0.00 sec)

mysql>
mysql> -- now let us see the table data
mysql> select * from tbl;
+------+-------+
| i    | v     |
+------+-------+
|    2 | two   |
|    3 | three |
+------+-------+
2 rows in set (0.00 sec)

mysql> select count(*) row_count from tbl;
+-----------+
| row_count |
+-----------+
|         2 |
+-----------+
1 row in set (0.00 sec)

mysql> select count(*) 'rows_affected' from rows_affected;
+---------------+
| rows_affected |
+---------------+
|             3 |
+---------------+
1 row in set (0.00 sec)

mysql>