mysql YUN YEO JOONG

1 Connecting to and Disconnecting from the Server 1 Connecting to and Disconnecting from the Server shell> mysql – h host -u user -p (Enter) password: ******** Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 459 to server version: a-log Type 'help' for help. mysql>

a SQL statement followed by a semicolon. (some exceptions QUIT ) When you issue a command, mysql sends it to the server for execution and displays the results, then prints another mysql>.

mysql displays query output as a table (rows and columns). Normally, column labels are the names of the columns you fetch from database tables. – If you're retrieving the value of an expression, mysql labels the column using the expression itself.

Here's a simple multiple-line statement: mysql> SELECT -> USER() ->, -> CURRENT_DATE; | USER() | CURRENT_DATE | | | |

In this example, notice how the prompt changes from mysql> to -> after you enter the first line of a multiple-line query. – This is how mysql indicates that it hasn't seen a complete statement and is waiting for the rest.

mysql> SELECT * FROM my_table WHERE name = "Smith AND age < 30; ">

2 Creating and Using a Database 2 Creating and Using a Database mysql> CREATE DATABASE menagerie; shell> mysql -hhost -uuser -p menagerie Enter password: ******** Creating a Table – mysql> SHOW TABLES; – Empty set (0.00 sec)

mysql> CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), -> species VARCHAR(20), sex CHAR(1), birth DATE, death DATE); mysql> DESCRIBE pet; mysql> INSERT INTO pet -> VALUES ('Puffball','Diane','hamster','f',' ',NULL);

3 Retrieving Information from a Table 3 Retrieving Information from a Table SELECT what_to_select FROM which_table WHERE conditions_to_satisfy – mysql> SELECT * FROM pet; mysql> UPDATE pet SET birth = " " WHERE name = "Bowser";

mysql> SELECT * FROM pet WHERE (species = "cat" AND sex = "m") -> OR (species = "dog" AND sex = "f"); Selecting Particular Columns – SELECT name, birth FROM pet; – SELECT DISTINCT owner FROM pet; – mysql> SELECT name, species, birth FROM pet -> WHERE species = "dog" OR species = "cat";

Sorting Rows – mysql> SELECT name, birth FROM pet ORDER BY birth; – mysql> SELECT name, birth FROM pet ORDER BY birth DESC;

Pattern Matching – mysql> SELECT * FROM pet WHERE name LIKE "b%"; Counting Rows – mysql> SELECT COUNT(*) FROM pet;

– mysql> SELECT species, COUNT(*) FROM pet GROUP BY species; – mysql> SELECT sex, COUNT(*) FROM pet GROUP BY sex;

4 Getting Information About Databases and Tables 4 Getting Information About Databases and Tables SELECT article, dealer, price FROM shop WHERE price=(SELECT MAX(price) FROM shop) SELECT article, dealer, price FROM shop s1 WHERE price=(SELECT MAX(s2.price) FROM shop s2 WHERE s1.article = s2.article);

5.API MYSQL *mysql_connect(MYSQL *mysql, const char *host, const char *user, const char *passwd) int mysql_create_db(MYSQL *mysql, const char *db) int mysql_drop_db(MYSQL *mysql, const char *db)

my_bool mysql_change_user(MYSQL *mysql, const char *user, const char *password, const char *db) void mysql_close(MYSQL *mysql) MYSQL *mysql_connect(MYSQL *mysql, const char *host, const char *user, const char *passwd)

int mysql_create_db(MYSQL *mysql, const char *db)