Aggregate functions in SQL perform calculations on multiple values from a column and return a single value. The document discusses various aggregate functions like COUNT, SUM, AVG, MIN, MAX and how they are used. It also covers topics like views, joins, constraints and how to create, update, delete views and constraints.
This document provides an overview of SQL (Structured Query Language). It defines SQL as a standard language for accessing and manipulating databases. It describes what SQL can do, such as execute queries, retrieve, insert, update and delete data. It also covers important SQL statements (SELECT, UPDATE, DELETE, INSERT), clauses (WHERE, ORDER BY), operators (LIKE), joins, and functions. In addition, it discusses SQL data types, constraints, creating tables and indexes.
The document provides information about various SQL concepts like views, triggers, functions, indexes, and joins. It defines views as virtual tables created by queries on other tables. Triggers are blocks of code that execute due to data modification language statements on tables. Functions allow reusable code and improve clarity. Indexes speed up searches by allowing fast data retrieval. Joins combine data from two or more tables based on relationships between columns. Stored procedures are SQL statements with an assigned name that are stored for shared use.
SQL constraints are rules that limit the type of data that can be stored in a table. They can be specified when a table is created or altered later. A primary key uniquely identifies each row and cannot be null. A composite key uses multiple columns as the primary key. A foreign key's values must exist in another table's primary key. Joins combine data from multiple tables and include inner, outer, cross, and other types of joins. Views are virtual tables that dynamically select data from other tables.
This document provides an overview of SQL Server database development concepts including SQL Server objects, tables, data types, relationships, constraints, indexes, views, queries, joins, stored procedures and more. It begins with introductory content on SQL Server and databases and then covers these topics through detailed explanations and examples in a structured outline.
SQL is a standard language for accessing and manipulating databases. It allows users to retrieve, insert, update, and delete data as well as create databases and tables. Common SQL queries include SELECT, UPDATE, DELETE, INSERT, CREATE DATABASE, ALTER DATABASE, CREATE TABLE, and ALTER TABLE.
This document provides guidance on optimizing database performance through techniques like indexing, query tuning, avoiding unnecessary operations, and following best practices for objects like stored procedures, triggers, views and transactions. It emphasizes strategies like indexing frequently accessed columns, avoiding correlated subqueries and unnecessary joins, tuning queries to select only required columns, and keeping transactions and locks as short as possible.
SQL is a standard language for creating and manipulating databases. It allows users to define, manipulate, and control access to data in a database. Some key capabilities of SQL include creating and deleting tables, inserting, updating, and deleting rows of data, retrieving data with queries, and setting access privileges for database users and applications. SQL is supported by many popular database systems like Oracle, MySQL, SQL Server, and PostgreSQL.
The document discusses various SQL concepts like views, triggers, functions, indexes, joins, and stored procedures. Views are virtual tables created by joining real tables, and can be updated, modified or dropped. Triggers automatically run code when data is inserted, updated or deleted from a table. Functions allow reusable code and improve clarity. Indexes allow faster data retrieval. Joins combine data from different tables. Stored procedures preserve data integrity.
This document provides an overview of SQL (Structured Query Language). It defines SQL as a standard language for accessing and manipulating databases. It describes what SQL can do, such as execute queries, retrieve, insert, update and delete data. It also covers important SQL statements (SELECT, UPDATE, DELETE, INSERT), clauses (WHERE, ORDER BY), operators (LIKE), joins, and functions. In addition, it discusses SQL data types, constraints, creating tables and indexes.
The document provides information about various SQL concepts like views, triggers, functions, indexes, and joins. It defines views as virtual tables created by queries on other tables. Triggers are blocks of code that execute due to data modification language statements on tables. Functions allow reusable code and improve clarity. Indexes speed up searches by allowing fast data retrieval. Joins combine data from two or more tables based on relationships between columns. Stored procedures are SQL statements with an assigned name that are stored for shared use.
SQL constraints are rules that limit the type of data that can be stored in a table. They can be specified when a table is created or altered later. A primary key uniquely identifies each row and cannot be null. A composite key uses multiple columns as the primary key. A foreign key's values must exist in another table's primary key. Joins combine data from multiple tables and include inner, outer, cross, and other types of joins. Views are virtual tables that dynamically select data from other tables.
This document provides an overview of SQL Server database development concepts including SQL Server objects, tables, data types, relationships, constraints, indexes, views, queries, joins, stored procedures and more. It begins with introductory content on SQL Server and databases and then covers these topics through detailed explanations and examples in a structured outline.
SQL is a standard language for accessing and manipulating databases. It allows users to retrieve, insert, update, and delete data as well as create databases and tables. Common SQL queries include SELECT, UPDATE, DELETE, INSERT, CREATE DATABASE, ALTER DATABASE, CREATE TABLE, and ALTER TABLE.
This document provides guidance on optimizing database performance through techniques like indexing, query tuning, avoiding unnecessary operations, and following best practices for objects like stored procedures, triggers, views and transactions. It emphasizes strategies like indexing frequently accessed columns, avoiding correlated subqueries and unnecessary joins, tuning queries to select only required columns, and keeping transactions and locks as short as possible.
SQL is a standard language for creating and manipulating databases. It allows users to define, manipulate, and control access to data in a database. Some key capabilities of SQL include creating and deleting tables, inserting, updating, and deleting rows of data, retrieving data with queries, and setting access privileges for database users and applications. SQL is supported by many popular database systems like Oracle, MySQL, SQL Server, and PostgreSQL.
The document discusses various SQL concepts like views, triggers, functions, indexes, joins, and stored procedures. Views are virtual tables created by joining real tables, and can be updated, modified or dropped. Triggers automatically run code when data is inserted, updated or deleted from a table. Functions allow reusable code and improve clarity. Indexes allow faster data retrieval. Joins combine data from different tables. Stored procedures preserve data integrity.
The document discusses constraints in SQL, specifically primary and foreign key constraints. It explains that primary keys uniquely identify each record in a table, while foreign keys link records between tables by referencing the primary keys. The document provides examples of creating tables with these constraints and explains how operations like INSERT, UPDATE, DELETE, and DROP TABLE interact with constraints. It also discusses SELECT statements and how they retrieve records from one or more tables.
SQL.pptx for the begineers and good knowPavithSingh
SQL is a standard language for storing, manipulating and retrieving data in relational databases. It allows users to define database structures, create tables, establish relationships between tables and query data. Popular uses of SQL include inserting, updating, deleting and selecting data from database tables. SQL is widely used across industries for managing large datasets efficiently in relational database management systems like MySQL, Oracle and SQL Server.
This document provides an introduction to SQL and PostgreSQL. It defines what a database and relational database are, and notes that PostgreSQL is an example of a relational database management system (RDBMS). It describes how data is organized in tables with rows and columns in a relational database. The document outlines common SQL commands like CREATE TABLE, SELECT, WHERE, JOIN, and functions. It provides examples of joining multiple tables and using subqueries.
This document discusses how to manage tables in a database including creating, modifying, and dropping tables. The key points are:
1. A table stores data in rows and columns and is created using the CREATE TABLE statement.
2. Tables can be modified using the ALTER TABLE statement to add, modify, or drop columns and constraints.
3. Integrity constraints like primary keys, foreign keys, checks and defaults are applied to tables to maintain data integrity.
4. External tables allow querying data stored outside the database in flat files and are created using the CREATE TABLE statement with the ORGANIZATION EXTERNAL clause.
This document discusses using SignalR and SQL dependency to create real-time updates from a database to clients. It describes how polling was used in the past versus SignalR pushing data instantly. SQL dependency allows a query to detect when results change and fire an event to SignalR. There are limitations on query types that can be monitored such as no aggregates, views, subqueries or other databases. A demo architecture is shown using SignalR to push flight info changes from a console app monitoring SQL dependency to multiple clients.
Constraints are the rules enforced on the data columns of a table. These are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the database.
Constraints can be divided into following two types:
Column level constraints : limits only column data
Table level constraints : limits whole table data
Aggregate Functions
SQL -Beginner To Intermediate Level.pdfDraguClaudiu
SQL is a programming language used for managing and manipulating relational databases. The document discusses SQL concepts like databases, tables, data types, queries, joins, constraints, views, stored procedures, and query optimization techniques. It provides examples of creating databases and tables, different types of joins, constraints, aggregate functions, and subqueries. The key difference between views and stored procedures is that views return data and stored procedures can accept parameters and modify data.
The document summarizes topics that will be covered in an advanced SQL training seminar, including SQL statement types, data types, aggregate functions, NULL handling, comparison operators, mathematical functions, joins, subqueries, views, materialized views, inline views, and optimizing SQL queries. Techniques for data sharing between databases are also mentioned. The seminar aims to provide in-depth knowledge of SQL concepts through explanations, examples, exercises and discussion.
This document provides an overview of Structured Query Language (SQL) and SQL Server by Brian Foote. It includes sections on SQL SELECT statements, joins, aggregate functions and more. The document covers basics like retrieving data from single and multiple tables, using ORDER BY, WHERE, and DISTINCT clauses. It also discusses aggregate functions like COUNT, MAX, MIN, AVG and SUM and using them with GROUP BY. Finally, it touches on other SQL topics like different join types, subqueries, temporary tables and exporting data to Excel.
The document discusses how to manipulate data using data manipulation language (DML) statements to insert, update, delete, and copy rows in database tables, as well as how transactions are used to group related DML statements and ensure data consistency through committing or rolling back changes. Key DML statements covered are INSERT, UPDATE, DELETE, as well as COMMIT and ROLLBACK statements to permanently save or discard pending changes to the database. The document also explains how read consistency is maintained in the database to allow concurrent read and write operations without conflicting data views.
This document discusses database management system concepts including joins and constraints. It defines SQL joins as combining data from two tables and describes four main types: inner, full, left, and right joins. It also covers integrity constraints such as not null, unique, primary key, foreign key, check, default, and index which are used to maintain data quality and prevent accidental damage to the database.
This document provides an overview of SQL Server and database development concepts. It covers topics such as SQL Server objects, databases, tables, data types, relationships, constraints, identity columns, computed columns, indexes, views, SQL statements for data manipulation and definition, operators like WHERE, ORDER BY, JOIN, and wildcards. The document is intended as a learning guide for those looking to develop databases using Microsoft SQL Server.
SQL constraints are rules that specify the type of data that can be stored in a table column. The document discusses various constraint types like NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK, and DEFAULT. It provides examples of how to specify each constraint when creating or altering tables using SQL syntax. Built-in functions in SQL are also covered, including numeric, string, date functions that can be used to manipulate and retrieve values.
Database is a collection of organized data that allows for easy updating and modification of stored data. Data is stored permanently in tables which organize data into rows and columns. SQL is the language used to access and modify database data using statements. DDL statements are used to define database schema through commands like Create, Alter, and Drop. DML statements manipulate data through Insert, Update, Delete, and Select commands. JDBC provides an API for connecting Java programs to databases to perform operations like executing statements and queries, and retrieving and modifying data.
The document provides examples and explanations of common SQL commands used to query, manipulate, and manage data in a relational database. Key points include:
- The SELECT statement is used to query data from database tables. The WHERE clause filters results.
- INSERT, UPDATE and DELETE statements are used to add, modify and remove rows in database tables.
- CREATE, ALTER, DROP statements manage the database schema by creating, modifying and deleting tables, columns, keys and constraints.
- PRIMARY KEY and FOREIGN KEY constraints enforce data integrity and relationships between tables.
This document introduces structured query language (SQL) and its basic commands and functions. It discusses how SQL is used for data administration, such as creating tables, indexes, and views, and for data manipulation like adding, modifying, deleting, and retrieving data. The two broad categories of SQL functions are data definition language for creating database objects and data manipulation language for inserting, updating, deleting, and retrieving data from tables.
Lec 1 = introduction to structured query language (sql)Faisal Anwar
This document provides an introduction to structured query language (SQL). It outlines the basic commands and functions of SQL for data administration and manipulation. SQL functions are divided into two categories: data definition language for creating database objects and tables, and data manipulation language for inserting, updating, deleting, and retrieving data. The document also covers topics such as data types, constraints, indexes, joins, and aggregate functions.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
The document discusses constraints in SQL, specifically primary and foreign key constraints. It explains that primary keys uniquely identify each record in a table, while foreign keys link records between tables by referencing the primary keys. The document provides examples of creating tables with these constraints and explains how operations like INSERT, UPDATE, DELETE, and DROP TABLE interact with constraints. It also discusses SELECT statements and how they retrieve records from one or more tables.
SQL.pptx for the begineers and good knowPavithSingh
SQL is a standard language for storing, manipulating and retrieving data in relational databases. It allows users to define database structures, create tables, establish relationships between tables and query data. Popular uses of SQL include inserting, updating, deleting and selecting data from database tables. SQL is widely used across industries for managing large datasets efficiently in relational database management systems like MySQL, Oracle and SQL Server.
This document provides an introduction to SQL and PostgreSQL. It defines what a database and relational database are, and notes that PostgreSQL is an example of a relational database management system (RDBMS). It describes how data is organized in tables with rows and columns in a relational database. The document outlines common SQL commands like CREATE TABLE, SELECT, WHERE, JOIN, and functions. It provides examples of joining multiple tables and using subqueries.
This document discusses how to manage tables in a database including creating, modifying, and dropping tables. The key points are:
1. A table stores data in rows and columns and is created using the CREATE TABLE statement.
2. Tables can be modified using the ALTER TABLE statement to add, modify, or drop columns and constraints.
3. Integrity constraints like primary keys, foreign keys, checks and defaults are applied to tables to maintain data integrity.
4. External tables allow querying data stored outside the database in flat files and are created using the CREATE TABLE statement with the ORGANIZATION EXTERNAL clause.
This document discusses using SignalR and SQL dependency to create real-time updates from a database to clients. It describes how polling was used in the past versus SignalR pushing data instantly. SQL dependency allows a query to detect when results change and fire an event to SignalR. There are limitations on query types that can be monitored such as no aggregates, views, subqueries or other databases. A demo architecture is shown using SignalR to push flight info changes from a console app monitoring SQL dependency to multiple clients.
Constraints are the rules enforced on the data columns of a table. These are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the database.
Constraints can be divided into following two types:
Column level constraints : limits only column data
Table level constraints : limits whole table data
Aggregate Functions
SQL -Beginner To Intermediate Level.pdfDraguClaudiu
SQL is a programming language used for managing and manipulating relational databases. The document discusses SQL concepts like databases, tables, data types, queries, joins, constraints, views, stored procedures, and query optimization techniques. It provides examples of creating databases and tables, different types of joins, constraints, aggregate functions, and subqueries. The key difference between views and stored procedures is that views return data and stored procedures can accept parameters and modify data.
The document summarizes topics that will be covered in an advanced SQL training seminar, including SQL statement types, data types, aggregate functions, NULL handling, comparison operators, mathematical functions, joins, subqueries, views, materialized views, inline views, and optimizing SQL queries. Techniques for data sharing between databases are also mentioned. The seminar aims to provide in-depth knowledge of SQL concepts through explanations, examples, exercises and discussion.
This document provides an overview of Structured Query Language (SQL) and SQL Server by Brian Foote. It includes sections on SQL SELECT statements, joins, aggregate functions and more. The document covers basics like retrieving data from single and multiple tables, using ORDER BY, WHERE, and DISTINCT clauses. It also discusses aggregate functions like COUNT, MAX, MIN, AVG and SUM and using them with GROUP BY. Finally, it touches on other SQL topics like different join types, subqueries, temporary tables and exporting data to Excel.
The document discusses how to manipulate data using data manipulation language (DML) statements to insert, update, delete, and copy rows in database tables, as well as how transactions are used to group related DML statements and ensure data consistency through committing or rolling back changes. Key DML statements covered are INSERT, UPDATE, DELETE, as well as COMMIT and ROLLBACK statements to permanently save or discard pending changes to the database. The document also explains how read consistency is maintained in the database to allow concurrent read and write operations without conflicting data views.
This document discusses database management system concepts including joins and constraints. It defines SQL joins as combining data from two tables and describes four main types: inner, full, left, and right joins. It also covers integrity constraints such as not null, unique, primary key, foreign key, check, default, and index which are used to maintain data quality and prevent accidental damage to the database.
This document provides an overview of SQL Server and database development concepts. It covers topics such as SQL Server objects, databases, tables, data types, relationships, constraints, identity columns, computed columns, indexes, views, SQL statements for data manipulation and definition, operators like WHERE, ORDER BY, JOIN, and wildcards. The document is intended as a learning guide for those looking to develop databases using Microsoft SQL Server.
SQL constraints are rules that specify the type of data that can be stored in a table column. The document discusses various constraint types like NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK, and DEFAULT. It provides examples of how to specify each constraint when creating or altering tables using SQL syntax. Built-in functions in SQL are also covered, including numeric, string, date functions that can be used to manipulate and retrieve values.
Database is a collection of organized data that allows for easy updating and modification of stored data. Data is stored permanently in tables which organize data into rows and columns. SQL is the language used to access and modify database data using statements. DDL statements are used to define database schema through commands like Create, Alter, and Drop. DML statements manipulate data through Insert, Update, Delete, and Select commands. JDBC provides an API for connecting Java programs to databases to perform operations like executing statements and queries, and retrieving and modifying data.
The document provides examples and explanations of common SQL commands used to query, manipulate, and manage data in a relational database. Key points include:
- The SELECT statement is used to query data from database tables. The WHERE clause filters results.
- INSERT, UPDATE and DELETE statements are used to add, modify and remove rows in database tables.
- CREATE, ALTER, DROP statements manage the database schema by creating, modifying and deleting tables, columns, keys and constraints.
- PRIMARY KEY and FOREIGN KEY constraints enforce data integrity and relationships between tables.
This document introduces structured query language (SQL) and its basic commands and functions. It discusses how SQL is used for data administration, such as creating tables, indexes, and views, and for data manipulation like adding, modifying, deleting, and retrieving data. The two broad categories of SQL functions are data definition language for creating database objects and data manipulation language for inserting, updating, deleting, and retrieving data from tables.
Lec 1 = introduction to structured query language (sql)Faisal Anwar
This document provides an introduction to structured query language (SQL). It outlines the basic commands and functions of SQL for data administration and manipulation. SQL functions are divided into two categories: data definition language for creating database objects and tables, and data manipulation language for inserting, updating, deleting, and retrieving data. The document also covers topics such as data types, constraints, indexes, joins, and aggregate functions.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
2. What is aggregate function?
• An aggregate function in SQL performs a calculation on multiple values and
returns a single value. SQL provides many aggregate functions that include avg,
count, sum, min, max, etc. An aggregate function ignores NULL values when it
performs the calculation, except for the count function.
• What is Aggregate Function in SQL?
• An aggregate function in SQL returns one value after calculating multiple values
of a column. We often use aggregate functions with the GROUP BY and HAVING
clauses of the SELECT statement.
• Various types of SQL aggregate functions are:
• Count()
• Sum()
• Avg()
• Min()
• Max()
3. COUNT FUNCTION
• The COUNT() function returns the number of rows in a database table.
• Syntax:
• COUNT(*)
• or
• COUNT( [ALL|DISTINCT] expression )
4. Sum Function
• The SUM() function returns the total sum of a numeric column.
• Syntax:
• SUM()
• or
• SUM( [ALL|DISTINCT] expression )
5. AVG Function
• The AVG() function calculates the average of a set of values.
• Syntax:
• AVG()
• or
• AVG( [ALL|DISTINCT] expression )
6. MIN Function
• The MIN() aggregate function returns the lowest value (minimum) in a set of non-
NULL values.
• Syntax:
• MIN()
• or
• MIN( [ALL|DISTINCT] expression )
7. MAX Function
• The MAX() aggregate function returns the highest value (maximum) in a set of
non-NULL values.
• Syntax:
• MAX()
• or
• MAX( [ALL|DISTINCT] expression )
8. VIEWS IN SQL
• In SQL, a view is a virtual table based on the result-set of an SQL statement.
• A view contains rows and columns, just like a real table. The fields in a view are
fields from one or more real tables in the database.
• You can add SQL statements and functions to a view and present the data as if the
data were coming from one single table.
• A view is created with the CREATE VIEW statement.
12. UPDATING VIEWS
• There are certain conditions needed to be satisfied to update a view. If any
one of these conditions is not met, then we will not be allowed to update the
view.
• The SELECT statement which is used to create the view should not include
GROUP BY clause or ORDER BY clause.
• The SELECT statement should not have the DISTINCT keyword.
• The View should have all NOT NULL values.
• The view should not be created using nested queries or complex queries.
• The view should be created from a single table. If the view is created using
multiple tables then we will not be allowed to update the view.
13. CREATE OR REPLACE VIEW MarksView AS
SELECT StudentDetails.NAME, StudentDetails.ADDRESS, StudentMarks.MARKS, StudentMarks.AGE
FROM StudentDetails, StudentMarks
WHERE StudentDetails.NAME = StudentMarks.NAME;
For example, if we want to update the view MarksView and add the field AGE to this View
from StudentMarks Table, we can do this as:
16. WITH CHECK OPTION
• The WITH CHECK OPTION clause in SQL is a very useful clause for
views. It is applicable to a updatable view. If the view is not updatable, then
there is no meaning of including this clause in the CREATE VIEW
statement.
• The WITH CHECK OPTION clause is used to prevent the insertion of rows
in the view where the condition in the WHERE clause in CREATE VIEW
statement is not satisfied.
• If we have used the WITH CHECK OPTION clause in the CREATE VIEW
statement, and if the UPDATE or INSERT clause does not satisfy the
conditions then they will return an error.
17.
18. JOINS IN SQL
• A JOIN clause is used to combine rows from two or more tables, based on a
related column between them.
20. • Different Types of SQL JOINs:
• (INNER) JOIN: Returns records that have matching values in both tables
• LEFT (OUTER) JOIN: Returns all records from the left table, and the matched
records from the right table
• RIGHT (OUTER) JOIN: Returns all records from the right table, and the matched
records from the left table
• FULL (OUTER) JOIN: Returns all records when there is a match in either left or
right table
21. SQL INNER JOIN Keyword
• The INNER JOIN keyword selects records that have matching values in both
tables.
• SELECT column_name(s)
FROM table1
INNER JOIN table2
ON table1.column_name = table2.column_name;
• Example:
• SELECT Orders.OrderID, Customers.CustomerName
FROM Orders
INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID;
22. SQL LEFT JOIN Keyword
• The LEFT JOIN keyword returns all records from the left table (table1), and the
matching records from the right table (table2). The result is 0 records from the
right side, if there is no match.
• Syntax:
• SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name = table2.column_name;
• Example:
• SELECT Customers.CustomerName, Orders.OrderID
FROM Customers
LEFT JOIN Orders ON Customers.CustomerID = Orders.CustomerID
ORDER BY Customers.CustomerName;
23. SQL RIGHT JOIN Keyword
• The RIGHT JOIN keyword returns all records from the right table (table2), and
the matching records from the left table (table1). The result is 0 records from the
left side, if there is no match.
• Syntax:
• SELECT column_name(s)
FROM table1
RIGHT JOIN table2
ON table1.column_name = table2.column_name;
• Example:
• SELECT Orders.OrderID, Employees.LastName, Employees.FirstName
FROM Orders
RIGHT JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID
ORDER BY Orders.OrderID;
24. SQL FULL OUTER JOIN Keyword
• The FULL OUTER JOIN keyword returns all records when there is a match in left
(table1) or right (table2) table records.
• Syntax:
• SELECT column_name(s)
FROM table1
FULL OUTER JOIN table2
ON table1.column_name = table2.column_name
WHERE condition;
• Example:
• SELECT Customers.CustomerName, Orders.OrderID
FROM Customers
FULL OUTER JOIN Orders ON Customers.CustomerID=Orders.CustomerID
ORDER BY Customers.CustomerName;
25. SQL SELF JOIN
• A self join is a regular join, but the table is joined with itself.
• Syntax
• SELECT column_name(s)
FROM table1 T1, table1 T2
WHERE condition;
26. Constraint
• Integrity Constraints are the rules enforced on the data columns of a table. These
are used to limit the type of data that can go into a table. This ensures the accuracy
and reliability of the data in the database.
• Constraints could be either on a column level or a table level. The column level
constraints are applied only to one column, whereas the table level constraints are
applied to the whole table.
• Following are some of the most commonly used constraints available in SQL.
• NOT NULL Constraint − Ensures that a column cannot have NULL value.
• DEFAULT Constraint − Provides a default value for a column when none is specified.
• UNIQUE Constraint − Ensures that all values in a column are different.
• PRIMARY Key − Uniquely identifies each row/record in a database table.
• FOREIGN Key − Uniquely identifies a row/record in any of the given database table.
• CHECK Constraint − The CHECK constraint ensures that all the values in a column satisfies certain
conditions.
• INDEX − Used to create and retrieve data from the database very quickly.
• Constraints can be specified when a table is created with the CREATE TABLE statement or you can use the
ALTER TABLE statement to create constraints even after the table is created.
27. • A primary key is a field in a database table that uniquely identifies each row/record. This
is also one type of Integrity Constraint.
• Primary keys must have distinct values. Null values are not allowed in a primary key
column. A table can only have one primary key, which can be made up of one or more
fields. It creates a composite key when several fields are used as a primary key.
• Foreign keys help ensure the consistency of your data while providing some ease. This is
also a type of integrity constraint. You are responsible for keeping track of inter-table
dependencies and preserving their consistency from within your applications .
• The not null constraint tells a column that it can't have any null values in it. This is also
a type of integrity constraint. This forces a field to always have a value, meaning you can't
create a new record or change an existing one without adding a value to it.
• A collection of one or more table fields/columns that uniquely identify a record in a
database table is known as a unique key. This is also a type of integrity constraint. It’s
similar to a primary key, but it can only accept one null value and cannot have duplicate
values. A Unique key is generated automatically.
28. DROPPING A CONSTRAINT
• Any constraint that you have defined can be dropped using the ALTER TABLE command with the
DROP CONSTRAINT option.
• For example, to drop the primary key constraint in the EMPLOYEES table, you can use the
following command.
• ALTER TABLE EMPLOYEES DROP CONSTRAINT EMPLOYEES_PK;
• Some implementations may provide shortcuts for dropping certain constraints. For example, to
drop the primary key constraint for a table in Oracle, you can use the following command.
• ALTER TABLE EMPLOYEES DROP PRIMARY KEY;