MySQL Tutorial/Select Query/Introduction
Содержание
- 1 Conditions can be combined to achieve better filtering of results
- 2 Hierarchy of Conditions
- 3 Join a many-to-many map table
- 4 Selecting Particular Columns
- 5 The basic SELECT statement syntax
- 6 The SELECT statement is used to pull information from a table
- 7 Three-Table Join
- 8 To sort a result, use an ORDER BY clause
- 9 Use String function in select statement
- 10 You can combine conditions
Conditions can be combined to achieve better filtering of results
<source lang="sql">
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 (0.02 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 (0.02 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 * FROM employee
-> WHERE ((employee.id = 2) AND (employee.city = "Vancouver"));
+------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 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>
Hierarchy of Conditions
<source lang="sql">
WHERE
| GROUP BY | |
HAVING ORDER BY
| | LIMIT</source>
GROUP BY cannot go before the WHERE condition.
LIMIT cannot go before HAVING.
HAVING and ORDER BY are at the same level.
Join a many-to-many map table
<source lang="sql">
mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 sec) mysql> mysql> mysql> INSERT INTO Books VALUES (12786, "Java", 1934),
-> (13331, "MySQL", 1919), -> (14356, "PHP", 1966), -> (15729, "PERL", 1932), -> (16284, "Oracle", 1996), -> (17695, "Pl/SQL", 1980), -> (19264, "JavaScript", 1992), -> (19354, "www.sqle.ru", 1993);
Query OK, 8 rows affected (0.02 sec) Records: 8 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> CREATE TABLE Authors(
-> AuthID SMALLINT NOT NULL PRIMARY KEY, -> AuthFN VARCHAR(20), -> AuthMN VARCHAR(20), -> AuthLN VARCHAR(20) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 sec) mysql> mysql> mysql> INSERT INTO Authors VALUES (1006, "H", "S.", "T"),
-> (1007, "J", "C", "O"), -> (1008, "B", NULL, "E"), -> (1009, "R", "M", "R"), -> (1010, "J", "K", "T"), -> (1011, "J", "G.", "N"), -> (1012, "A", NULL, "P"), -> (1013, "A", NULL, "W"), -> (1014, "N", NULL, "A");
Query OK, 9 rows affected (0.03 sec) Records: 9 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> CREATE TABLE AuthorBook(
-> AuthID SMALLINT NOT NULL, -> BookID SMALLINT NOT NULL, -> PRIMARY KEY (AuthID, BookID), -> FOREIGN KEY (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.06 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.03 sec) Records: 8 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> select * from Authors; +--------+--------+--------+--------+ | AuthID | AuthFN | AuthMN | AuthLN | +--------+--------+--------+--------+ | 1006 | H | S. | T | | 1007 | J | C | O | | 1008 | B | NULL | E | | 1009 | R | M | R | | 1010 | J | K | T | | 1011 | J | G. | N | | 1012 | A | NULL | P | | 1013 | A | NULL | W | | 1014 | N | NULL | A | +--------+--------+--------+--------+ 9 rows in set (0.00 sec) mysql> select * from Books; +--------+----------------+-----------+ | BookID | BookTitle | Copyright | +--------+----------------+-----------+ | 12786 | Java | 1934 | | 13331 | MySQL | 1919 | | 14356 | PHP | 1966 | | 15729 | PERL | 1932 | | 16284 | Oracle | 1996 | | 17695 | Pl/SQL | 1980 | | 19264 | JavaScript | 1992 | | 19354 | www.sqle.ru | 1993 | +--------+----------------+-----------+ 8 rows in set (0.00 sec) mysql> select * from AuthorBook; +--------+--------+ | AuthID | BookID | +--------+--------+ | 1009 | 12786 | | 1006 | 14356 | | 1008 | 15729 | | 1011 | 15729 | | 1014 | 16284 | | 1010 | 17695 | | 1012 | 19264 | | 1012 | 19354 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> SELECT BookTitle, Copyright, ab.AuthID
-> FROM Books AS b JOIN AuthorBook AS ab -> ON b.BookID=ab.BookID -> ORDER BY BookTitle;
+----------------+-----------+--------+ | BookTitle | Copyright | AuthID | +----------------+-----------+--------+ | Java | 1934 | 1009 | | JavaScript | 1992 | 1012 | | Oracle | 1996 | 1014 | | PERL | 1932 | 1008 | | PERL | 1932 | 1011 | | PHP | 1966 | 1006 | | Pl/SQL | 1980 | 1010 | | www.sqle.ru | 1993 | 1012 | +----------------+-----------+--------+ 8 rows in set (0.00 sec) mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.02 sec) mysql> drop table Books; Query OK, 0 rows affected (0.05 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.05 sec)</source>
Selecting Particular Columns
<source lang="sql">
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 (0.00 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 (0.02 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 (0.01 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 first_name, last_name FROM employee; +------------+-----------+ | first_name | last_name | +------------+-----------+ | Jason | Martin | | Alison | Mathews | | James | Smith | | Celia | Rice | | Robert | Black | | Linda | Green | | David | Larry | | James | Cat | +------------+-----------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql></source>
The basic SELECT statement syntax
<source lang="sql">
SELECT columns FROM table [WHERE (condition)]</source>
The SELECT statement is used to pull information from a table
The general form of the statement is:
<source lang="sql">
SELECT what_to_select FROM which_table WHERE conditions_to_satisfy;</source>
what_to_select is what you want to see.
what_to_select can be a list of columns
* to indicate "all columns."
which_table is the table name list.
The WHERE clause is optional.
If where clause is present, conditions_to_satisfy specifies conditions that rows must satisfy.
Three-Table Join
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> INSERT INTO Books VALUES (12786, "Java", 1934),
-> (13331, "MySQL", 1919), -> (14356, "PHP", 1966), -> (15729, "PERL", 1932), -> (16284, "Oracle", 1996), -> (17695, "Pl/SQL", 1980), -> (19264, "JavaScript", 1992), -> (19354, "www.sqle.ru", 1993);
Query OK, 8 rows affected (0.03 sec) Records: 8 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> CREATE TABLE Authors(
-> AuthID SMALLINT NOT NULL PRIMARY KEY, -> AuthFN VARCHAR(20), -> AuthMN VARCHAR(20), -> AuthLN VARCHAR(20) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.06 sec) mysql> mysql> mysql> INSERT INTO Authors VALUES (1006, "H", "S.", "T"),
-> (1007, "J", "C", "O"), -> (1008, "B", NULL, "E"), -> (1009, "R", "M", "R"), -> (1010, "J", "K", "T"), -> (1011, "J", "G.", "N"), -> (1012, "A", NULL, "P"), -> (1013, "A", NULL, "W"), -> (1014, "N", NULL, "A");
Query OK, 9 rows affected (0.03 sec) Records: 9 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> CREATE TABLE AuthorBook(
-> AuthID SMALLINT NOT NULL, -> BookID SMALLINT NOT NULL, -> PRIMARY KEY (AuthID, BookID), -> FOREIGN KEY (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.05 sec) Records: 8 Duplicates: 0 Warnings: 0 mysql> mysql> mysql> select * from Authors; +--------+--------+--------+--------+ | AuthID | AuthFN | AuthMN | AuthLN | +--------+--------+--------+--------+ | 1006 | H | S. | T | | 1007 | J | C | O | | 1008 | B | NULL | E | | 1009 | R | M | R | | 1010 | J | K | T | | 1011 | J | G. | N | | 1012 | A | NULL | P | | 1013 | A | NULL | W | | 1014 | N | NULL | A | +--------+--------+--------+--------+ 9 rows in set (0.00 sec) mysql> select * from Books; +--------+----------------+-----------+ | BookID | BookTitle | Copyright | +--------+----------------+-----------+ | 12786 | Java | 1934 | | 13331 | MySQL | 1919 | | 14356 | PHP | 1966 | | 15729 | PERL | 1932 | | 16284 | Oracle | 1996 | | 17695 | Pl/SQL | 1980 | | 19264 | JavaScript | 1992 | | 19354 | www.sqle.ru | 1993 | +--------+----------------+-----------+ 8 rows in set (0.00 sec) mysql> select * from AuthorBook; +--------+--------+ | AuthID | BookID | +--------+--------+ | 1009 | 12786 | | 1006 | 14356 | | 1008 | 15729 | | 1011 | 15729 | | 1014 | 16284 | | 1010 | 17695 | | 1012 | 19264 | | 1012 | 19354 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> SELECT BookTitle, Copyright, CONCAT_WS(" ", AuthFN, AuthMN, AuthLN) AS Author
-> FROM Books JOIN AuthorBook USING (BookID) -> JOIN Authors USING (AuthID) -> WHERE Copyright<1980 -> ORDER BY BookTitle;
+-----------+-----------+--------+ | BookTitle | Copyright | Author | +-----------+-----------+--------+ | Java | 1934 | R M R | | PERL | 1932 | B E | | PERL | 1932 | J G. N | | PHP | 1966 | H S. T | +-----------+-----------+--------+ 4 rows in set (0.00 sec) mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.01 sec) mysql> drop table Books; Query OK, 0 rows affected (0.05 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.06 sec)</source>
To sort a result, use an ORDER BY clause
<source lang="sql">
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 (0.02 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 (0.02 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 first_name, start_date FROM employee ORDER BY start_date; +------------+------------+ | first_name | start_date | +------------+------------+ | Alison | 1976-03-21 | | James | 1978-12-12 | | Celia | 1982-10-24 | | Robert | 1984-01-15 | | Linda | 1987-07-30 | | David | 1990-12-31 | | Jason | 1996-07-25 | | James | 1996-09-17 | +------------+------------+ 8 rows in set (0.02 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql></source>
Use String function in select statement
<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 (0.01 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 (0.02 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 concat(First_Name, " ",Last_Name) AS Name FROM Employee; +----------------+ | Name | +----------------+ | Jason Martin | | Alison Mathews | | James Smith | | Celia Rice | | Robert Black | | Linda Green | | David Larry | | James Cat | +----------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql></source>
You can combine conditions
<source lang="sql">
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 (0.02 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 (0.02 sec) mysql> mysql> mysql> mysql> mysql> SELECT * FROM employee WHERE first_name = "Celia" AND city = "Vancouver"; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 1 row in set (0.02 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.01 sec) mysql></source>