QCE Digital Solutions Unit 2: Relational databases, SQL and normalisation

1 What SQL is 2 SQL SELECT and FROM 3 SQL WHERE conditions 4 Boolean operators AND, OR and NOT in a WHERE clause 5 Pattern matching with LIKE, % and _ 6 BETWEEN and IN in a WHERE clause 7 SQL ORDER BY 8 SQL aggregate functions: COUNT, SUM, AVG, MIN, MAX 9 SQL GROUP BY 10 Clause order in a full SQL query 11 Why a query over two tables needs a join 12 Writing the ON condition: foreign key equals primary key 13 Table-qualified field names in a join 14 Table aliases in a join 15 A join with WHERE and ORDER BY 16 Joining three tables 17 A join that forgets the ON condition 18 SQL UPDATE and DELETE 19 CREATE TABLE and INSERT INTO 20 FOREIGN KEY ... REFERENCES in CREATE TABLE 21 SQL ALTER TABLE 22 SQL CREATE VIEW 23 SQL constraints for validation 24 What is a relational database? 25 Counting fields and records in a table 26 Entity 27 Attributes become fields 28 Primary key 29 Foreign key and table relationships 30 Secondary key 31 Null values 32 Views in a relational database 33 One-to-many relationships between tables 34 One-to-one and many-to-many relationships 35 Entity relationship diagram: entities and relationship lines 36 Crow's foot notation for one and many 37 Referential integrity 38 Reading a relational schema 39 Drawing an ERD from a scenario 40 Unnormalised data and why normalise 41 First normal form (1NF) (Data and Programming Techniques) 42 Second normal form (2NF) (Data and Programming Techniques) 43 Third normal form (3NF) (Data and Programming Techniques) 44 Normalising a table to 3NF step by step