SQL/MySQL/String/String Append — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Версия 13:46, 26 мая 2010
Содержание
Append string in select clause
/*
mysql> select * from employee;
+----+-----------+----------+----------------------------+------+---------------+--------+-------+---------------------+
| id | firstname | lastname | title | age | yearofservice| salary | perks | email |
+----+-----------+----------+----------------------------+------+---------------+--------+-------+---------------------+
| 1 | John | Chen | Senior Programmer | 31 | 3| 120000 | 25000 | j@hotmail.ru |
| 2 | Jan | Pillai | Senior Programmer | 32 | 4| 110000 | 20000 | g@yahoo.ru |
| 3 | Ane | Pandit | Web Designer | 24 | 3| 90000 | 15000 | a@gmail.ru |
| 4 | Mary | Anchor | Web Designer | 27 | 2| 85000 | 15000 | m@mail.ru |
| 5 | Fred | King | Programmer | 32 | 3| 75000 | 15000 | f@net.ru |
| 6 | John | Mac | Programmer | 32 | 4| 80000 | 16000 | j@hotmail.ru |
| 7 | Arthur | Sam | Programmer | 28 | 2| 75000 | 14000 | e@yahoo.ru |
| 8 | Alok | Nanda | Programmer | 32 | 3| 70000 | 10000 | a@yahoo.ru |
| 9 | Susan | Ra | Multimedia Programmer | 32 | 4| 90000 | 15000 | h@gmail.ru |
| 10 | Paul | Simon | Multimedia Programmer | 23 | 1| 85000 | 12000 | ps@gmail.ru |
| 11 | Edward | Parhar | Multimedia Programmer | 30 | 2| 75000 | 15000 | a@hotmail.ru |
| 12 | Kim | Hunter | Senior Web Designer | 32 | 4| 110000 | 20000 | kim@coolmail.ru |
| 13 | Roger | Lewis | System Administrator | 32 | 3| 100000 | 13000 | roger@mail.ru |
| 14 | Danny | Gibson | System Administrator | 31 | 2| 90000 | 12000 | danny@hotmail.ru |
| 15 | Mike | Harper | Senior Marketing Executive | 36 | 1| 120000 | 28000 | m@gmail.ru |
| 16 | Mary | Sunday | Marketing Executive | 31 | 5| 90000 | 25000 | monica@bigmail.ru |
| 17 | Jack | Sim | Marketing Executive | 27 | 1| 70000 | 18000 | hal@gmail.ru |
| 18 | Joe | Irvine | Marketing Executive | 27 | 1| 72000 | 18000 | joseph@hotmail.ru |
| 19 | Henry | Ali | Customer Service Manager | 32 | 3| 70000 | 9000 | shahida@hotmail.ru |
| 20 | Peter | Champion | Finance Manager | 32 | 2| 120000 | 25000 | peter@yahoo.ru |
+----+-----------+----------+----------------------------+------+---------------+--------+-------+---------------------+
20 rows in set (0.00 sec)
mysql> SELECT CONCAT(firstname, " ", lastName)
-> from employee
-> where title = "Programmer";
+----------------------------------+
| CONCAT(firstname, " ", lastName) |
+----------------------------------+
| Fred King |
| John Mac |
| Arthur Sam |
| Alok Nanda |
+----------------------------------+
4 rows in set (0.00 sec)
*/
Drop table employee;
CREATE TABLE employee (
id int unsigned not null auto_increment primary key,
firstname varchar(20),
lastname varchar(20),
title varchar(30),
age int,
yearofservice int,
salary int,
perks int,
email varchar(60)
);
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("John", "Chen", "Senior Programmer", 31, 3, 120000, 25000, "j@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Jan", "Pillai", "Senior Programmer", 32, 4, 110000, 20000, "g@yahoo.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Ane", "Pandit", "Web Designer", 24, 3, 90000, 15000, "a@gmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Mary", "Anchor", "Web Designer", 27, 2, 85000, 15000, "m@mail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Fred", "King", "Programmer", 32, 3, 75000, 15000, "f@net.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("John", "Mac", "Programmer", 32, 4, 80000, 16000, "j@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Arthur", "Sam", "Programmer", 28, 2, 75000, 14000, "e@yahoo.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Alok", "Nanda", "Programmer", 32, 3, 70000, 10000, "a@yahoo.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Susan", "Ra", "Multimedia Programmer", 32, 4, 90000, 15000, "h@gmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Paul", "Simon", "Multimedia Programmer", 23, 1, 85000, 12000, "ps@gmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Edward", "Parhar", "Multimedia Programmer", 30, 2, 75000, 15000, "a@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Kim", "Hunter", "Senior Web Designer", 32, 4, 110000, 20000, "kim@coolmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Roger", "Lewis", "System Administrator", 32, 3, 100000, 13000, "roger@mail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Danny", "Gibson", "System Administrator", 31, 2, 90000, 12000, "danny@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Mike", "Harper", "Senior Marketing Executive", 36, 1, 120000, 28000, "m@gmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Mary", "Sunday", "Marketing Executive", 31, 5, 90000, 25000, "monica@bigmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Jack", "Sim", "Marketing Executive", 27, 1, 70000, 18000, "hal@gmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Joe", "Irvine", "Marketing Executive", 27, 1, 72000, 18000, "joseph@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Henry", "Ali", "Customer Service Manager", 32, 3, 70000, 9000, "shahida@hotmail.ru");
INSERT INTO employee (firstname, lastName, title, age, yearofservice, salary, perks, email) values ("Peter", "Champion", "Finance Manager", 32, 2, 120000, 25000, "peter@yahoo.ru");
select * from employee;
SELECT CONCAT(firstname, " ", lastName)
from employee
where title = "Programmer";
Concatenate string with NULL value
/*
mysql> select CONCAT("a",null);
+------------------+
| CONCAT("a",null) |
+------------------+
| NULL |
+------------------+
1 row in set (0.00 sec)
*/
select CONCAT("a",null);
Concatenating String Values: Joining Strings
/*
mysql> SELECT ClassID, CONCAT(Time, ", Room ", RoomID) AS ClassDetails
-> FROM Class;
+---------+------------------------------------------+
| ClassID | ClassDetails |
+---------+------------------------------------------+
| 1 | Mon 09:30-11:00, Room 6 |
| 2 | Mon 11:30-12:00, Thu 09:00-11:00, Room 5 |
| 3 | Mon 14:30-16:00, Room 3 |
+---------+------------------------------------------+
3 rows in set (0.00 sec)
*/
/* Prepare the data */
Drop TABLE Class;
CREATE TABLE Class (
CourseID INT NOT NULL,
RoomID INT NOT NULL,
ClassID INT NOT NULL PRIMARY KEY,
Time VARCHAR(50)
)TYPE = InnoDB;
/* Insert data for testing */
INSERT INTO Class (ClassID,CourseID,RoomID,Time) VALUES (1,1,6,"Mon 09:30-11:00");
INSERT INTO Class (ClassID,CourseID,RoomID,Time) VALUES (2,2,5,"Mon 11:30-12:00, Thu 09:00-11:00");
INSERT INTO Class (ClassID,CourseID,RoomID,Time) VALUES (3,3,3,"Mon 14:30-16:00");
/* Real command */
SELECT ClassID, CONCAT(Time, ", Room ", RoomID) AS ClassDetails
FROM Class;
Simplest concatenate string 2
/*
mysql> select CONCAT("a","B");
+-----------------+
| CONCAT("a","B") |
+-----------------+
| aB |
+-----------------+
1 row in set (0.00 sec)
*/
select CONCAT("a","B");
Simplest concatenate string: space
/*
mysql> select CONCAT("a"," ","B");
+---------------------+
| CONCAT("a"," ","B") |
+---------------------+
| a B |
+---------------------+
1 row in set (0.00 sec)
*/
select CONCAT("a"," ","B");
String function: concat
/*
mysql> Drop table Employees;
ERROR 1051 (42S02): Unknown table "employees"
mysql> CREATE TABLE Employees
-> (
-> EmpID SMALLINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
-> EmpFN VARCHAR(20) NOT NULL,
-> EmpMN VARCHAR(20) NULL,
-> EmpLN VARCHAR(20) NOT NULL
-> )
-> ENGINE=INNODB;
Query OK, 0 rows affected (0.13 sec)
mysql> INSERT INTO Employees (EmpFN, EmpMN, EmpLN)
-> VALUES ("John", "P.", "Smith"),
-> ("Robert", NULL, "Schroader"),
-> ("Mary", "Marie", "Michaels"),
-> ("John", NULL, "Laguci"),
-> ("Rita", "C.", "Carter"),
-> ("George", NULL, "Brooks");
Query OK, 6 rows affected (0.04 sec)
Records: 6 Duplicates: 0 Warnings: 0
mysql> SELECT EmpID, UPPER(CONCAT_WS(" ", EmpFN, EmpMN, EmpLN)) AS Name,
-> CONCAT(LOWER(LEFT(EmpFN, 2)), LOWER(LEFT(EmpLN, 3)), EmpID) AS RegID
-> FROM Employees
-> ORDER BY EmpID;
+-------+---------------------+--------+
| EmpID | Name | RegID |
+-------+---------------------+--------+
| 1 | JOHN P. SMITH | josmi1 |
| 2 | ROBERT SCHROADER | rosch2 |
| 3 | MARY MARIE MICHAELS | mamic3 |
| 4 | JOHN LAGUCI | jolag4 |
| 5 | RITA C. CARTER | ricar5 |
| 6 | GEORGE BROOKS | gebro6 |
+-------+---------------------+--------+
6 rows in set (0.02 sec)
mysql>
*/
Drop table Employees;
CREATE TABLE Employees
(
EmpID SMALLINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
EmpFN VARCHAR(20) NOT NULL,
EmpMN VARCHAR(20) NULL,
EmpLN VARCHAR(20) NOT NULL
)
ENGINE=INNODB;
INSERT INTO Employees (EmpFN, EmpMN, EmpLN)
VALUES ("John", "P.", "Smith"),
("Robert", NULL, "Schroader"),
("Mary", "Marie", "Michaels"),
("John", NULL, "Laguci"),
("Rita", "C.", "Carter"),
("George", NULL, "Brooks");
SELECT EmpID, UPPER(CONCAT_WS(" ", EmpFN, EmpMN, EmpLN)) AS Name,
CONCAT(LOWER(LEFT(EmpFN, 2)), LOWER(LEFT(EmpLN, 3)), EmpID) AS RegID
FROM Employees
ORDER BY EmpID;