Advanced_SQL_Presentation_Template.pptx
Download as PPTX, PDF0 likes7 views
This document summarizes an advanced SQL training session that covered: 1. An overview of relational databases and MySQL as an RDBMS tool. 2. How MySQL Workbench can be used to visually design databases. 3. Key concepts like constraints, keys, and cascading that help maintain data integrity. Constraints impose restrictions on data, keys are used for indexing and integrity, and cascading automatically propagates changes between linked tables.
Advanced_SQL_Presentation_Template.pptx
- 1. Advanced SQL – Session 1 #LifeKoKaroLift 26-02-2023 1
- 2. Edit Master text styles Edit Master text styles 26-02-2023 2 Lecture On : Advanced SQL Instructor : Edwin R. Das
- 3. 26-02-2023 3 Today’s Agenda What is an RDBMS? Review of key concepts Using MySQL Workbench Cascading and referential integrity Types of keys – Primary, Unique and Foreign keys Data Science Certification
- 4. 26-02-2023 What is a Relational Database? • A collection of inter-related data. • It is organised in the form of schema, tables and views. • It is efficient to retrieve, insert and delete data from a database. 4 Databases – An Overview What is a RDBMS? • It is a software that is used to manage a database. • It helps in the following: • Defining the way in which data is organised • Updating and retrieving data • User access management
- 5. SQL Statements Structured Query Language (SQL): • It is a way to communicate with database. • All operations on a database are performed through SQL statements. • Queries to the database can be expressed using logical statements. • SQL statements allows one to express complex queries using a very simple language. • It is very easy to read and comprehend for humans. 26-02-2023 5
- 6. Your mentor will share career advice and can help expand your professional network. 6 SQL Statements 26-02-2023 6 Data Definition Language (DDL) Statements: ALTER, CREATE, DROP, RENAME, TRUNCATE Data Manipulation Language (DML) Statements: SELECT, UPDATE, DELETE, ALTER, INSERT Data Control Language (DCL) Statements: GRANT, REVOKE Transaction Control Language (TCL) Statements: COMMIT, ROLLBACK, SAVEPOINT
- 7. Inner Join Only common data from both tables 7 Joins 26-02-2023 Outer Join All data from both tables Left Outer Join All rows from left table, only matching from right Right Outer Join All rows from right table, only matching ones from left
- 8. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 8 Poll 1 26-02-2023 11 Which of the following statements is used to fetch data from database table? 1. INSERT 2. UPDATE 3. SELECT 4. FETCH
- 9. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 9 Poll 1(Answer) 26-02-2023 11 Which of the following statements is used to fetch data from database table? 1. INSERT 2. UPDATE 3. SELECT 4. FETCH
- 10. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 10 Poll 2 26-02-2023 11 What is the main difference between UPDATE and INSERT? 1. UPDATE and INSERT work in the same way 2. UPDATE modifies existing records while INSERT adds new records 3. UPDATE adds new columns while INSERT adds new rows 4. None of the above
- 11. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 11 Poll 2(Answer) 26-02-2023 11 What is the main difference between UPDATE and INSERT? 1. UPDATE and INSERT work in the same way 2. UPDATE modifies existing records while INSERT adds new records 3. UPDATE adds new columns while INSERT adds new rows 4. None of the above
- 12. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 12 Poll 3 26-02-2023 11 What is the difference between DROP and TRUNCATE? 1. DROP deletes the table but TRUNCATE is not a valid SQL statement 2. TRUNCATE deletes table while DROP only deletes records but keeps table structure 3. DROP deletes table while TRUNCATE only deletes records but keeps table structure 4. None of the above
- 13. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 13 Poll 3(Answer) 26-02-2023 11 What is the difference between DROP and TRUNCATE? 1. DROP deletes the table but TRUNCATE is not a valid SQL statement 2. TRUNCATE deletes table while DROP only deletes records but keeps table structure 3. DROP deletes table while TRUNCATE only deletes records but keeps table structure 4. None of the above
- 14. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 14 Poll 4 26-02-2023 11 If Table A has 40 rows and Table B has 20 rows and both the tables are combined using a CROSS join, how many rows will the result set have: 1. 40 2. 800 3. 20 4. 400
- 15. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 15 Poll 4(Answer) 26-02-2023 11 If Table A has 40 rows and Table B has 20 rows and both the tables are combined using a CROSS join, how many rows will the result set have: 1. 40 2. 800 3. 20 4. 400
- 16. 26-02-2023 16 • MySQL is a relational database management system. • MySQL workbench is a visual database design and modelling access tool. • It is useful for creating a visual model of a database which can be easily translated into a database. • It has a in built sql editor which can be used to create and query MySQL server databases. • The data can be exported easily to commonly used formats. • Using tabs, one can work on multiple databases at a time. • It is also an administration tool which can be used for user access control, backup and restore and configuring the MySQL server. MySQL Workbench
- 17. 26-02-2023 17 MySQL Workbench • This the first screen you see when opening MySQL Workbench. • The first step would be to create a connection by clicking on the ‘+’ sign next to MySQL Connections.
- 18. 26-02-2023 18 MySQL Workbench • Enter the name of the connection in the ‘Connection Name’ field. • Use the default values for the rest of the fields. Enter the name for the connection here.
- 20. 26-02-2023 20 Constraints are rules or conditions for the data in a table. Constraints may be at the column level or table level. The following are common constraints in MySQL. NOT NULL - Ensures that a column cannot have null values UNIQUE - Ensures that all values in a column are distinct PRIMARY KEY - A column that uniquely identifies each row in a table FOREIGN KEY - A column that references the primary key of another table CHECK - Imposes specific conditions on a column DEFAULT - Sets a default value for a column if unspecified INDEX - A column can be set as an index. Used to speed up data retrieval Constraints
- 21. 26-02-2023 21 Keys are used to maintain referential integrity in a database. Keys are also indexes for a table in MySQL. Indexes speed up data retrieval from database tables. PRIMARY KEY – A unique identifier for each row in a table. Eg: Student Id, Employee Code, etc. It can also be a combination of multiple columns. In this case it is also know as a composite key. UNIQUE KEY – A column which allows only unique values. Eg: Phone number, email id, etc. FOREIGN KEY - A column that references the primary key of another table. Primarily used to maintain referential integrity KEYS
- 22. 26-02-2023 22 • Foreign keys are not just used to refer to the primary key of another table. • It is also used to control delete and update actions on the table which contains the primary key. • This helps in maintaining referential integrity. • When implemented, any changes made to the table containing the primary key will also correspondingly DELETE or UPDATE the same on any foreign keys referencing that table. Cascading
- 23. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 23 Poll 5 26-02-2023 11 Which of following are true? 1. Primary keys cannot have null values 2. Foreign Keys can have duplicate values 3. Unique keys cannot have null values 4. A foreign key cannot be composite
- 24. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 24 Poll 5(Answer) 26-02-2023 11 Which of following are true? 1. Primary keys cannot have null values 2. Foreign Keys can have duplicate values 3. Unique keys cannot have null values 4. A foreign key cannot be composite
- 25. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 25 Poll 6 26-02-2023 11 Which of the following constraints provides a value in column even if no value is entered by the user? 1. CHECK 2. DEFAULT 3. UNIQUE 4. NOT NULL
- 26. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 26 Poll 7 26-02-2023 11 Cascading delete implies that: 1. Deleting a row in the parent table will also delete the corresponding row in the child table 2. Deleting a row in the child table will also delete the corresponding row in the parent table 3. One cannot delete a row in the child table without deleting the corresponding row in the parent table 4. None of the above
- 27. Click to add Title 26-02-2023 Footer Practice in teams of 4 students Industry expert mentoring to learn better Get personalised feedback for improvements 27 Poll 7 26-02-2023 11 Cascading delete implies that: 1. Deleting a row in the parent table will also delete the corresponding row in the child table 2. Deleting a row in the child table will also delete the corresponding row in the parent table 3. One cannot delete a row in the child table without deleting the corresponding row in the parent table 4. None of the above
- 28. 26-02-2023 28 Key Takeaway 1. A relational database is a collection of inter related data. 2. MySQL is an RDBMS which is used to manage a database. 3. MySQL workbench is a software that can be used to design databases visually. 4. Constraints impose restrictions on the data that can be entered into a database. 5. Keys are indexes which can be used speed up data retrieval and maintain referential integrity. 6. Cascading is a type of constraint that helps maintain referential integrity with foreign keys. Data Science Certification
- 29. 26-02-2023 29 Next Class SQL Functions Data Science Certification