MySQL Tutorial/Math Numeric Functions/EXP — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Текущая версия на 09:49, 26 мая 2010
EXP(X) returns the value of e (the base of natural logarithms) raised to the power of X
mysql>
mysql>
mysql> SELECT EXP(2);
+-----------------+
| EXP(2) |
+-----------------+
| 7.3890560989307 |
+-----------------+
1 row in set (0.00 sec)
mysql> SELECT EXP(-2);
+------------------+
| EXP(-2) |
+------------------+
| 0.13533528323661 |
+------------------+
1 row in set (0.00 sec)
mysql> SELECT EXP(0);
+--------+
| EXP(0) |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)
mysql>
Using EXP function with data in a table
mysql>
mysql>
mysql> create table myTable(
-> id int(2),
-> value FLOAT(6,2)
-> );
Query OK, 0 rows affected (0.03 sec)
mysql>
mysql> insert into myTable(ID, value)values (1,9);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (2,2.11);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (3,3.44);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (4,-4.21);
Query OK, 1 row affected (0.01 sec)
mysql> insert into myTable(ID, value)values (5,10);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (6,3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (7,-5.88);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (8,123.45);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (9,98.23);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (10,938.23);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (11,-984.23);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (12,198.23);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (13,-928.87);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (14,25.37);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (15,-918.3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (16,9.23);
Query OK, 1 row affected (0.00 sec)
mysql> insert into myTable(ID, value)values (17,-8.23);
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> select * from myTable;
+------+---------+
| id | value |
+------+---------+
| 1 | 9.00 |
| 2 | 2.11 |
| 3 | 3.44 |
| 4 | -4.21 |
| 5 | 10.00 |
| 6 | 3.00 |
| 7 | -5.88 |
| 8 | 123.45 |
| 9 | 98.23 |
| 10 | 938.23 |
| 11 | -984.23 |
| 12 | 198.23 |
| 13 | -928.87 |
| 14 | 25.37 |
| 15 | -918.30 |
| 16 | 9.23 |
| 17 | -8.23 |
+------+---------+
17 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql> select value, EXP(value) from myTable;
+---------+----------------------+
| value | EXP(value) |
+---------+----------------------+
| 9.00 | 8103.0839275754 |
| 2.11 | 8.2482404193518 |
| 3.44 | 31.186959952842 |
| -4.21 | 0.014846367771743 |
| 10.00 | 22026.465794807 |
| 3.00 | 20.085536923188 |
| -5.88 | 0.0027947849551991 |
| 123.45 | 4.1082083938205e+053 |
| 98.23 | 4.57876564137e+042 |
| 938.23 | 1.#INF |
| -984.23 | 0 |
| 198.23 | 1.2308164504724e+086 |
| -928.87 | 0 |
| 25.37 | 104244072681.15 |
| -918.30 | 0 |
| 9.23 | 10198.536843185 |
| -8.23 | 0.0002665364522633 |
+---------+----------------------+
17 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql>
mysql> drop table myTable;
Query OK, 0 rows affected (0.02 sec)
mysql>
mysql>