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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== A NULL value will be returned if you try to divide by zero==



<source lang="sql">
mysql>
mysql>
mysql>
mysql> CREATE TABLE Employee(
-> id int,
-> first_name VARCHAR(15),
-> last_name VARCHAR(15),
-> start_date DATE,
-> end_date DATE,
-> salary FLOAT(8,2),
-> city VARCHAR(10),
-> description VARCHAR(15)
-> );
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.02 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.02 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> select * from Employee;
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| id | first_name | last_name | start_date | end_date | salary | city | description |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer |
| 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester |
| 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester |
| 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager |
| 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester |
| 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester |
| 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager |
| 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
8 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql>
mysql> SELECT (salary / 0) as Result FROM Employee;
+--------+
| Result |
+--------+
| NULL |
| NULL |
| NULL |
| NULL |
| NULL |
| NULL |
| NULL |
| NULL |
+--------+
8 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.02 sec)</source>

== Arithmetic Operators==

Name
Description
/
Division operator
DIV
Integer division
-
Minus operator
%
Modulo operator
+
Addition operator
*
Times operator
-
Change the sign of the argument

== Numeric Functions==

Name
Description
ABS()
Return the absolute value
ACOS()
Return the arc cosine
ASIN()
Return the arc sine
ATAN2(), ATAN()
Return the arc tangent of the two arguments
ATAN()
Return the arc tangent
CEILING(), CEIL()
Return the smallest integer value not less than the argument
COS()
Return the cosine
COT()
Return the cotangent
CRC32()
Compute a cyclic redundancy check value
DEGREES()
Convert radians to degrees
EXP()
Raise to the power of
FLOOR()
Return the largest integer value not greater than the argument
LN()
Return the natural logarithm of the argument
LOG10()
Return the base-10 logarithm of the argument
LOG2()
Return the base-2 logarithm of the argument
LOG()
Return the natural logarithm of the first argument
MOD()
Return the remainder
PI()
Return the value of pi
POW(), POWER()
Return the argument raised to the specified power
RADIANS()
Return argument converted to radians
RAND()
Return a random floating-point value
ROUND()
Round the argument
SIGN()
Return the sign of the argument
SIN()
Return the sine of the argument
SQRT()
Return the square root of the argument
TAN()
Return the tangent of the argument
TRUNCATE()
Truncate to specified number of decimal places
<p>Quote: dev.mysql.ru/doc/refman/5.1/en/index.html</p>

== SUM then Multiply==



<source lang="sql">
mysql>
mysql>
mysql>
mysql> CREATE TABLE Employee(
-> id int,
-> first_name VARCHAR(15),
-> last_name VARCHAR(15),
-> start_date DATE,
-> end_date DATE,
-> salary FLOAT(8,2),
-> city VARCHAR(10),
-> description VARCHAR(15)
-> );
Query OK, 0 rows affected (0.02 sec)
mysql>
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> select * from Employee;
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| id | first_name | last_name | start_date | end_date | salary | city | description |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer |
| 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester |
| 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester |
| 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager |
| 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester |
| 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester |
| 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager |
| 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
8 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql> SELECT SUM(salary * 2) AS Product FROM Employee;
+----------+
| Product |
+----------+
| 65148.04 |
+----------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)</source>

== To add the totals of both columns for every row==



<source lang="sql">
mysql>
mysql>
mysql>
mysql> CREATE TABLE Employee(
-> id int,
-> first_name VARCHAR(15),
-> last_name VARCHAR(15),
-> start_date DATE,
-> end_date DATE,
-> salary FLOAT(8,2),
-> city VARCHAR(10),
-> description VARCHAR(15)
-> );
Query OK, 0 rows affected (0.02 sec)
mysql>
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> select * from Employee;
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| id | first_name | last_name | start_date | end_date | salary | city | description |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer |
| 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester |
| 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester |
| 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager |
| 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester |
| 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester |
| 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager |
| 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
8 rows in set (0.01 sec)
mysql>
mysql>
mysql>
mysql> SELECT (SUM(salary) + SUM(salary)) as Total FROM Employee;
+----------+
| Total |
+----------+
| 65148.04 |
+----------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)
mysql></source>

== Total the two columns and then subtract them==



<source lang="sql">
mysql>
mysql>
mysql>
mysql> CREATE TABLE Employee(
-> id int,
-> first_name VARCHAR(15),
-> last_name VARCHAR(15),
-> start_date DATE,
-> end_date DATE,
-> salary FLOAT(8,2),
-> city VARCHAR(10),
-> description VARCHAR(15)
-> );
Query OK, 0 rows affected (0.03 sec)
mysql>
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> select * from Employee;
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| id | first_name | last_name | start_date | end_date | salary | city | description |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer |
| 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester |
| 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester |
| 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager |
| 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester |
| 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester |
| 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager |
| 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
8 rows in set (0.00 sec)
mysql>
mysql>
mysql>
mysql>
mysql> SELECT (SUM(salary) - salary) as Difference FROM Employee;
+------------+
| Difference |
+------------+
| 31339.46 |
+------------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)
mysql></source>

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