report作业 | 作业mining | 代写lab | 代做sql | database – IS-4420 Database Fundamentals

IS-4420 Database Fundamentals

report作业 | 作业mining | 代写lab | 代做sql | database – 这是一个mining面向对象设计的practice, 考察mining的理解, 包括了report/mining/sql/database等方面, 该题目是值得借鉴的lab代写的题目

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lab 4

u1263525 luzaixun

1: Initial Setup (4 points)

1.
2.

2: Data Definition Language (DDL) (6 points)

ERD:

Create tables:

3: Data Manipulation Language (DML) (6 points)

5 : Review (4 points)

1 - Describe why data types are necessary and what is important to keep in mind when deter mining the
data types for each column in your tables.
Because the scope of the data is limited by the data type, it is equivalent to adding scope
constraints, optimizing the storage format of the data, and reducing the storage of abnormal data.
The important point in choosing a data type is to choose one that is large enough to store the
values the column will have while minimizing the storage footprint of the database.
2 - Describe why it is so important to create each table in the correct order, and why it is equally
important to insert the rows in the correct order.
The order of table creation is very important when there is a foreign key constraint. If there is a
foreign key between the tables, the primary key table must be created first, and then the foreign
key table is created, so that the correct table constraint can be created, otherwise the database
will  report an error.
The order of table creation is very important when there are foreign key constraints. First insert
the data of the primary key table, and then insert the data of the foreign key table, so that the
 database will not report an error when performing referential integrity check on the data of the
foreign key table.
3 - What is the difference between DDL vs DML?
Data Definition Language (DDL):
Commands that are used to define (implement the structure of) the Schema of the database,
including creating, altering, & dropping tables & other objects.
Data Manipulation Language (DML):
Commands used to manage the data in the database, such as SELECT (reading), INSERT, UPDATE,
and DELETE operations.
4 - In class, we learned about the ANSI- sql Standard that all major relational databases adhere to.
Describe the benefits & reasons you would want to write SQL code that is compliant with the ANSI-
SQL standard.
Because most relational databases follow the ANSI-SQL standard, writing SQL code that conforms
to the ANSI-SQL standard can be used in most relational databases. Such SQL has good generality
and understanding.