QBE stands for _______ By Example. (hint: Q_____y)

We can write queries using QBE in Access.

We can write queries using Relational Algebra in Access.

In a relational database, each entity is stored in a table or relation.

A table must have some columns or fields.

In a relational database, a relationship is implemented through some common fields or columns between two relations or tables.

A relation is a table, and a column is a field.

A record is a row, and a row is a column.

In a relational database, an entry of a field can be a set of values.

A table may have many rows or no rows at all.

A table may have many columns or no columns at all.

In a table, order of columns is not important, but is meaningful to users and developers.

In a relational database, some duplicate rows are allowed in a table.

An un-normalized relation is a structure that satisfies all properties of a relation except that some entries in the table are NOT single-valued.

In a table, an entry is NOT single-valued if it contains repeating groups.

The primary key of a table R is the column(s) (in R) that can uniquely identify every row in R.

In QBE query, we may specify " > 21 " on Criteria: row under Age column.

In QBE query, we may add a computed field like "AvailableCredit: CreditLimit - Balance" using the Zoom dialog box.

In QBE queries, we may use aggregate functions such as Count, Sum, Avg, Max, and Min.

In QBE queries, we may use "Group By" on the Total: row under a column.

In QBE queries, we cannot sort on multiple keys.

To select data from two tables, we need to join two tables based on the matching fields in the corresponding columns.

In Access, a join line indicates that the tables are related between primary key (PK) and foreign key (FK).

In Access, we cannot join multiple tables in a query.

The following query is valid in Relational Algebra. PROJECT Client OVER (ClientNum , ClientName) GIVING Answer ;

Outer join is to join records from each original table that is common to both tables.

In Relational Algebra, division of 2 tables is to create a table by concatenating every row in first table with every row in second table.

SQL stands for ________ Query Language. (hint: S______d)

DBA stands for Data Base Administrator.

If the Tasks table has been defined , the following SQL query is valid in Access. SELECT * FROM TABLE Tasks ;

The following SQL query will display all rows and all columns of the Student table. SELECT * FROM Student ;

Assuming the table and the columns have been defined properly, the following SQL query is valid in Access. SELECT ClientNum , ClientName , CreditLimit - Balance AS AvailableCredit FROM Client ;

Assuming all the tables and columns have been defined properly, the following SQL command is valid to run. SELECT A , B , C FROM R1 WHERE A IN ( SELECT A FROM R2 WHERE D = 'A' ) ;

In SQL, we should specify at least 3 join conditions in order to join 5 tables properly to get the meaningful result.

The following SQL command will delete only one record from the Student table. DELETE FROM Student WHERE GPA = 4.0 ;

The following SQL command will create a new table called Student2, which is identical to the Student table for all columns and all rows. SELECT * INTO Student2 FROM Student ;

The result of a SELECT query may not be a table sometimes.

Assuming all the tables and columns have been defined properly, the following SQL command is valid to run. SELECT DeptID, COUNT(*) AS NumberOfStudents, AVG( GPA) FROM Student GROUP BY DeptID HAVING AVG(GPA) > 3.4 ORDER BY DeptID ;

In SQL, we cannot write a query inside another query because that would make the query not structured.

The following SQL query will display the number of tasks of 'HOT' Category in the Tasks table. SELECT COUNT(*) FROM Tasks WHERE Category = ‘HOT’ ;