SQL/MySQL/String/String Append
Содержание
Append string in select clause
<source lang="sql">
/* 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";
</source>
Concatenate string with NULL value
<source lang="sql">
/* mysql> select CONCAT("a",null); +------------------+ | CONCAT("a",null) | +------------------+ | NULL | +------------------+ 1 row in set (0.00 sec)
- /
select CONCAT("a",null);
</source>
Concatenating String Values: Joining Strings
<source lang="sql">
/* 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;
</source>
Simplest concatenate string 2
<source lang="sql">
/* mysql> select CONCAT("a","B"); +-----------------+ | CONCAT("a","B") | +-----------------+ | aB | +-----------------+ 1 row in set (0.00 sec)
- /
select CONCAT("a","B");
</source>
Simplest concatenate string: space
<source lang="sql">
/* mysql> select CONCAT("a"," ","B"); +---------------------+ | CONCAT("a"," ","B") | +---------------------+ | a B | +---------------------+ 1 row in set (0.00 sec)
- /
select CONCAT("a"," ","B");
</source>
String function: concat
<source lang="sql">
/* 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;
</source>