1. Day 3 - Basics of MySQL What is MySQL What is MySQL How to make basic tables How to make basic tables Simple MySQL commands. Simple MySQL commands.

2. CSE 498Day 3 - Basics of MySQL2 / 8 What is MySQL? MySQL is a true multi-user, multi-threaded SQL database server. SQL is the most popular relational database in the world. MySQL is a true multi-user, multi-threaded SQL database server. SQL is the most popular relational database in the world. Goals of system: Goals of system: –Client/server implementation of a relational database system. –Speed of transactions and queries going through. –Robustness of the system. –Easy to use and learn. –Be able to handle large systems easily and quickly.

3. CSE 498Day 3 - Basics of MySQL3 / 8 Relational DB Relational DB –A relational database is the reality of a E/R diagram model. It uses the basic parts of the E/R diagram and enforces them in a database. Basic Parts Basic Parts –Keys & Attributes are the same –Table: Entity relation of a E/R diagram. –Record: An instance of a row of data in a table. What is a relational database?

4. CSE 498Day 3 - Basics of MySQL4 / 8 Data Types & Basics Data Types Data Types –Integers: TinyInt, SmallInt, MediumInt, Int, BigInt –Real Numbers: Float, Double, Decimal, Real –Time: Date, DateTime, Timestamp, Time, Year (Y2K Compliant) –String: Char, VarChar –Text: TinyText, MediumText, LongText Basic MySQL Commands Basic MySQL Commands –Note: All commands/queries end with a semi-colon. –show tables; Command will show you the name of all the tables currently in the DB.Command will show you the name of all the tables currently in the DB. – desc ; Command will show you information about the requested table.Command will show you information about the requested table.

5. CSE 498Day 3 - Basics of MySQL5 / 8 CREATE TABLE command Command for creating a table in the DB Command for creating a table in the DB –CREATE TABLE table_name (attribute definition, …) –attribute definition : column_name data_type (options) –options : NOT NULL/NULL, AUTO INCREMENT, PRIMARY KEY, DEFAULT default_value, PRIMARY KEY, DEFAULT default_value, (reference_definition) (reference_definition) –reference_definition : REFERENCE table_name (column_name, …) MATCH FULL/MATCH PARTIAL MATCH FULL/MATCH PARTIAL Example: Category table from Day 2 Example: Category table from Day 2 > CREATE TABLE category (cat_id INT NOT NULL PRIMARY KEY, cat_name var_char NOT NULL); > CREATE TABLE category (cat_id INT NOT NULL PRIMARY KEY, cat_name var_char NOT NULL);

6. CSE 498Day 3 - Basics of MySQL6 / 8 ALTER TABLE & DROP TABLE Command ALTER TABLE - Used to change a table. ALTER TABLE - Used to change a table. –ALTER TABLE table_name (alter_spec) –Three basic alter_specs: ADD : Used to add a column, index specification, or primary key specificationADD : Used to add a column, index specification, or primary key specification CHANGE: Used to change a column specification in the tableCHANGE: Used to change a column specification in the table DROP: Used to drop a column from the table.DROP: Used to drop a column from the table. –Example: Add a column to the category table. > ALTER TABLE category ADD cat_alias var_char NULL; > ALTER TABLE category ADD cat_alias var_char NULL; DROP TABLE - Used to delete a table. DROP TABLE - Used to delete a table. –DROP TABLE table_name –Note: Be careful with this one because once it’s gone, it’s gone.

7. CSE 498Day 3 - Basics of MySQL7 / 8 Used to insert data into tables. Used to insert data into tables. Format Format –INSERT INTO table_name (col_name, …) VALUES (expression, …), (expression, …), … Example: Insert info into the category table… Example: Insert info into the category table… > INSERT INTO category (cat_id, cat_name) VALUES (1, “Action/Adventure”); > INSERT INTO category (cat_id, cat_name) VALUES (1, “Action/Adventure”); Insert Command

8. CSE 498Day 3 - Basics of MySQL8 / 8 DELETE & UPDATE Commands Both commands use a query format to run the command on the data in a table. Queries are explained in the next set of slides. Both commands use a query format to run the command on the data in a table. Queries are explained in the next set of slides. DELETE - Used to delete information from a table. DELETE - Used to delete information from a table. –DELETE FROM table_name WHERE (rule) –Example: Delete the ‘oldies’ category from the table. > DELETE FROM category WHERE cat_name = “Oldies”; UPDATE - Used to update table information. UPDATE - Used to update table information. –UPDATE table_name SET col_name = expression WHERE (rule) –Example: Change category “Scary Movies” to “Horror” > UPDATE category SET cat_name = “Horror” WHERE cat_name = “Scary Movies”;