в 13:44, 26 мая 2010

2010-05-26T13:44:56Z

Admin: 1 версия

2010-05-26T09:49:46Z

1 версия

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== Sign a list of data==



<source lang="sql">
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 (0.00 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 (0.02 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 (10,0);
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 (12,0);
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 (14,0);
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 | 0.00 |
| 11 | 984.23 |
| 12 | 0.00 |
| 13 | 928.87 |
| 14 | 0.00 |
| 15 | 918.30 |
| 16 | 9.23 |
| 17 | 8.23 |
+------+--------+
17 rows in set (0.00 sec)
mysql>
mysql>
mysql> select value, sign(value) from myTable;
+--------+-------------+
| value | sign(value) |
+--------+-------------+
| 9.00 | 1 |
| 2.11 | 1 |
| 3.44 | 1 |
| -4.21 | -1 |
| 10.00 | 1 |
| 3.00 | 1 |
| -5.88 | -1 |
| 123.45 | 1 |
| 98.23 | 1 |
| 0.00 | 0 |
| 984.23 | 1 |
| 0.00 | 0 |
| 928.87 | 1 |
| 0.00 | 0 |
| 918.30 | 1 |
| 9.23 | 1 |
| 8.23 | 1 |
+--------+-------------+
17 rows in set (0.00 sec)
mysql>
mysql> drop table myTable;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql></source>

== SIGN(X) returns the sign of the argument as or 1, depending on whether X is negative, zero, or positive==



<source lang="sql">
mysql>
mysql> SELECT SIGN(-32);
+-----------+
| SIGN(-32) |
+-----------+
| -1 |
+-----------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT SIGN(0);
+---------+
| SIGN(0) |
+---------+
| 0 |
+---------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT SIGN(234);
+-----------+
| SIGN(234) |
+-----------+
| 1 |
+-----------+
1 row in set (0.00 sec)
mysql></source>

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в 13:44, 26 мая 2010

Admin: 1 версия