SQL: SQL stands for “Structured Query Language”. The current version of SQL is “ANSI SQL – 92”. It contains constructs which are used to define and process database . They are executed using DBMS-supplied command prompt. SQL is not a programming language. It is text-based and it is also called as data sublanguage. In order to get SQL as a complete programming language, it should be included in scripting languages like Java, C#, and so on. Display values from table: The contents from the table can be viewed by using “SELECT” statement which comes under Data Manipulation Language (DML). Syntax to view the contents using asterisk () is as follows: SELECT FROM table_Name; Grouping Rows: SQL contains “GROUP BY” clause in order to group rows by common data. Though it is very powerful feature, it is hard to understand. Syntax: SELECT column_Name1 FROM table_Name GROUP BY column_Name2; Example: Consider a table “student” contains two columns “student_Name” and “Department”. “GROUP BY” clause is used when there is a need to get the number of students from each department. The query for this scenario is given as follows. SELECT department, COUNT (department) FROM student GROUP BY department; When the above query is executed, number of students from each department will be displayed.

Question

Want to see the full answer?

Answer 1

Question

Chapter 3, Problem 3.32RQ

Program Plan Intro

SQL:

SQL stands for “Structured Query Language”.

The current version of SQL is “ANSI SQL – 92”.

It contains constructs which are used to define and process database. They are executed using DBMS-supplied command prompt.

SQL is not a programming language. It is text-based and it is also called as data sublanguage. In order to get SQL as a complete programming language, it should be included in scripting languages like Java, C#, and so on.

Display values from table:

The contents from the table can be viewed by using “SELECT” statement which comes under Data Manipulation Language (DML). Syntax to view the contents using asterisk () is as follows:

SELECT FROM table_Name;

Grouping Rows:

SQL contains “GROUP BY” clause in order to group rows by common data. Though it is very powerful feature, it is hard to understand.

Syntax:

SELECT column_Name1 FROM table_Name GROUP BY column_Name2;

Example: Consider a table “student” contains two columns “student_Name” and “Department”. “GROUP BY” clause is used when there is a need to get the number of students from each department.

The query for this scenario is given as follows.

SELECT department, COUNT (department) FROM student GROUP BY department;

When the above query is executed, number of students from each department will be displayed.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

cases: Compare the Poisson approximation with the correct binomial probability for the following a. P{X=2} when n = 8, p = 0.2 b. P{X 5} when n = 10, p = 0.5 c. P{X=0} when n = 20, p = 0.2 d. P{X=3} when n = 9, p = 0.1

4. Suppose that the average number of cars abandoned weekly on a certain highway is λ = 1.68. Approximate the probability that there will be (a) No abandoned cars in the next week. (b) At least 2 abandoned cars in the next week. Hint: Model the problem with a Poisson random variable.

od The probability mass function of a discrete random variable X is given by P(X = 1) = {} x=1,2,3,4 10 otherwise (a) Draw the probability mass function (PMF) of this random variable. (b) Draw the cumulative distribution function (CDF) of this random variable. (c) What is P{2< x <4}? Write it in terms of the CDF. (d) What is E[X]? (e) What is Var[X]? (f) What is E[X (6-X)]? (g) What is Var[3X - 2]?