MySQL Tutorial/Select Query/Introduction

Материал из SQL эксперт
Перейти к: навигация, поиск

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>