WGU D427 DATA MANAGEMENT – APPLICATIONS 2023 EXAM WITH QUESTIONS AND
VERIFIED ANSWERS|GRADED A+
1. Database model: A database model is a conceptual framework for database systems, with three parts:
- Data structures that prescribe how data is organized.
- Operations that manipulate data structures.
- Rules that govern valid data.
2. Relational model: The relational model is a database model based on a tabular data structure. The model was
published in 1970 by E. F. Codd of IBM and released in commercial products around 1980. The data structure, operations,
#$%^&*(
and rules are standardized in SQL, the universal query language of relational databases.
3. Big data: The rise of the internet in the 1990s generated big data, characterized by unprecedented data volumes and
rapidly changing data structures.
4. Set: A set is an unordered collection of elements enclosed in braces.
5. Tuple: A tuple is an ordered collection of elements enclosed in parentheses.
6. Table: A table has a name, a fixed tuple of columns, and a varying set of rows.
7. Column: A column has a name and a data type.
8. Row: A row is an unnamed tuple of values. Each value corresponds to a column and belongs to the column's data
type.
9. Data type: A data type is a named set of values, from which column values are drawn.
10. Relational algebra: These operations are collectively called relational algebra and are the theoretical foundation
of the SQL language.
11. Relational rules: Relational rules are part of the relational model and govern data in every relational database.
12. Business rules: Business rules are based on business policy and specific to a particular database.
13. Constraints: Relational rules are implemented as SQL constraints and enforced by the database system.
14. Structured Query Language / SQL: Structured Query Language (SQL) is a high-level computer language for
storing, manipulating, and retrieving data.
15. Statement: An SQL statement is a complete command composed of one or more clauses.
16. Clause: A clause groups SQL keywords like SELECT, FROM, and WHERE with table names like City, column
names like Name, and conditions like Population > 100000.
17. Data Definition Language: Data Definition Language (DDL) defines the struc- ture of the database.
18. Data Query Language: Data Query Language (DQL) retrieves data from the database.
, 19. Data Manipulation Language: Data Manipulation Language (DML) manipu- lates data stored in a database.
20. Data Control Language: Data Control Language (DCL) controls database user access.
21. DataTransaction Language: Data Transaction Language (DTL) manages data- base transactions.
22. Database system instance: A database system instance is a single executing copy of a database system. Personal
computers usually run just one instance of a database system. Shared computers, such as computers used for cloud
services, usually run multiple instances of a database system.
23. CREATE DATABASE databasename: CREATE DATABASE databasename creates a new database.
24. DROP DATABASE databasename: DROP DATABASE databasename deletes a database, including all
tables in the database.
25. USE databasename: USE databasename selects a default database for use in subsequent SQL statements.
26. SHOW DATABASES: SHOW DATABASES lists all databases in the database system instance.
27. SHOW TABLES: SHOW TABLES lists all tables in the default database.
28. SHOW COLUMNS FROM tablename: SHOW COLUMNS FROM tablename
Lists all columns in the tablename table of the default database.
29. SHOW CREATE TABLE tablename: SHOW CREATE TABLE tablename
Shows the CREATE TABLE statement for the tablename table of the default data- base.
30. Table: A table has a name, a fixed sequence of columns, and a varying set of rows.
31. Row: A row is an unnamed sequence of values. Each value corresponds to a column and belongs to the column's
data type.
32. Cell: A cell is a single column of a single row.
33. Empty table: A table without rows is called an empty table.
34. Data independence: Rule 4 is called data independence.
35. CREATE TABLE: The CREATE TABLE statement creates a new table by spec- ifying the table name, column
names, and column data types.
36. DROP TABLE: The DROP TABLE statement deletes a table, along with all the table's rows, from a database.
37. ALTER TABLE: The ALTER TABLE statement adds, deletes, or modifies columns on an existing table.
38. Data type: A data type is a named set of values from which column values are drawn.
VERIFIED ANSWERS|GRADED A+
1. Database model: A database model is a conceptual framework for database systems, with three parts:
- Data structures that prescribe how data is organized.
- Operations that manipulate data structures.
- Rules that govern valid data.
2. Relational model: The relational model is a database model based on a tabular data structure. The model was
published in 1970 by E. F. Codd of IBM and released in commercial products around 1980. The data structure, operations,
#$%^&*(
and rules are standardized in SQL, the universal query language of relational databases.
3. Big data: The rise of the internet in the 1990s generated big data, characterized by unprecedented data volumes and
rapidly changing data structures.
4. Set: A set is an unordered collection of elements enclosed in braces.
5. Tuple: A tuple is an ordered collection of elements enclosed in parentheses.
6. Table: A table has a name, a fixed tuple of columns, and a varying set of rows.
7. Column: A column has a name and a data type.
8. Row: A row is an unnamed tuple of values. Each value corresponds to a column and belongs to the column's data
type.
9. Data type: A data type is a named set of values, from which column values are drawn.
10. Relational algebra: These operations are collectively called relational algebra and are the theoretical foundation
of the SQL language.
11. Relational rules: Relational rules are part of the relational model and govern data in every relational database.
12. Business rules: Business rules are based on business policy and specific to a particular database.
13. Constraints: Relational rules are implemented as SQL constraints and enforced by the database system.
14. Structured Query Language / SQL: Structured Query Language (SQL) is a high-level computer language for
storing, manipulating, and retrieving data.
15. Statement: An SQL statement is a complete command composed of one or more clauses.
16. Clause: A clause groups SQL keywords like SELECT, FROM, and WHERE with table names like City, column
names like Name, and conditions like Population > 100000.
17. Data Definition Language: Data Definition Language (DDL) defines the struc- ture of the database.
18. Data Query Language: Data Query Language (DQL) retrieves data from the database.
, 19. Data Manipulation Language: Data Manipulation Language (DML) manipu- lates data stored in a database.
20. Data Control Language: Data Control Language (DCL) controls database user access.
21. DataTransaction Language: Data Transaction Language (DTL) manages data- base transactions.
22. Database system instance: A database system instance is a single executing copy of a database system. Personal
computers usually run just one instance of a database system. Shared computers, such as computers used for cloud
services, usually run multiple instances of a database system.
23. CREATE DATABASE databasename: CREATE DATABASE databasename creates a new database.
24. DROP DATABASE databasename: DROP DATABASE databasename deletes a database, including all
tables in the database.
25. USE databasename: USE databasename selects a default database for use in subsequent SQL statements.
26. SHOW DATABASES: SHOW DATABASES lists all databases in the database system instance.
27. SHOW TABLES: SHOW TABLES lists all tables in the default database.
28. SHOW COLUMNS FROM tablename: SHOW COLUMNS FROM tablename
Lists all columns in the tablename table of the default database.
29. SHOW CREATE TABLE tablename: SHOW CREATE TABLE tablename
Shows the CREATE TABLE statement for the tablename table of the default data- base.
30. Table: A table has a name, a fixed sequence of columns, and a varying set of rows.
31. Row: A row is an unnamed sequence of values. Each value corresponds to a column and belongs to the column's
data type.
32. Cell: A cell is a single column of a single row.
33. Empty table: A table without rows is called an empty table.
34. Data independence: Rule 4 is called data independence.
35. CREATE TABLE: The CREATE TABLE statement creates a new table by spec- ifying the table name, column
names, and column data types.
36. DROP TABLE: The DROP TABLE statement deletes a table, along with all the table's rows, from a database.
37. ALTER TABLE: The ALTER TABLE statement adds, deletes, or modifies columns on an existing table.
38. Data type: A data type is a named set of values from which column values are drawn.
