Introduction to .NET with C#

Kursinnehåll

Introduction to .NET with C#

Introduction to .NET with C#

1. Introduction

What is the .NET Platform exactly?Creating a Console Application Taking input from the User Task - Building a Simple Calculator Dealing with Exceptions caused by User Input Task - Improving the Calculator Reading Files Writing Files Task - File Based Calculator

2. Asynchronous Programming and Introduction to Web Services

What is Asynchronous Programming?Implementing an Asynchronous Method Task - Asynchronously Reading Files Introduction to APIs Making a GET Request Task - Using an API Handling Exceptions caused by HTTP Request Task - Exception Handling for API Response

3. Introduction to Databases with .NET

What is a Database?Structure of a Relational Database Setting Up A MySQL Server Connecting to the MySQL Server Task - Writing Connection Strings Executing Commands Task - Executing MySQL Commands MySqlCommand Methods Task - Connecting to a MySQL Database and Executing Commands

4. CRUD Operations with MySQL

Introduction to CRUD Operations Installing & Using MySQL Workbench CREATE - Part I Task - Using CREATE CREATE - Part II Task - Using INSERT Read Task - Using SELECT Update Task - Using UPDATE Delete - Part I Delete - Part II Task - Using DELETE

5. Optimizing Database Operations

Stored Procedures Task - Executing Stored Procedures DataReader vs DataSet DataAdapter & DataSet Task - Reading Tables using MySqlDataAdapter What's Next?

MySqlCommand Methods

Note

If you're unable to delete objects from the MySQL server, it is possible that the server is running in safe mode. To disable safe mode, you can run the following query: SET SQL_SAFE_UPDATES=0;.

Important Points

We use ExecuteNonQuery for commands which modify the database;
ExecuteReader and ExecuteScalar are for querying commands that retrieve data from the database;
ExecuteReader returns a MySqlDataReader object;
MySqlDataReader has a method called read() which reads the rows in a sequential manner; We need to Close() the MySqlDataReader object after use;
ExecuteScalar returns an object which can be type-casted into the appropriate data type.

1. The following command selects and returns all the students that have marks higher than 90, which command is the most appropriate for executing this query?

2. The following command selects and returns the name of the oldest student in the class, which command is the most appropriate for executing this query?

The following command selects and returns all the students that have marks higher than 90, which command is the most appropriate for executing this query?

Select the correct answer

ExecuteReader

ExecuteNonQuery

ExecuteScalar

The following command selects and returns the name of the oldest student in the class, which command is the most appropriate for executing this query?

Select the correct answer

ExecuteReader

ExecuteNonQuery

ExecuteScalar

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 3. Kapitel 8

Fråga AI

Fråga vad du vill eller prova någon av de föreslagna frågorna för att starta vårt samtal

Kursinnehåll

Introduction to .NET with C#

Introduction to .NET with C#

1. Introduction

What is the .NET Platform exactly?Creating a Console Application Taking input from the User Task - Building a Simple Calculator Dealing with Exceptions caused by User Input Task - Improving the Calculator Reading Files Writing Files Task - File Based Calculator

2. Asynchronous Programming and Introduction to Web Services

What is Asynchronous Programming?Implementing an Asynchronous Method Task - Asynchronously Reading Files Introduction to APIs Making a GET Request Task - Using an API Handling Exceptions caused by HTTP Request Task - Exception Handling for API Response

3. Introduction to Databases with .NET

What is a Database?Structure of a Relational Database Setting Up A MySQL Server Connecting to the MySQL Server Task - Writing Connection Strings Executing Commands Task - Executing MySQL Commands MySqlCommand Methods Task - Connecting to a MySQL Database and Executing Commands

4. CRUD Operations with MySQL

Introduction to CRUD Operations Installing & Using MySQL Workbench CREATE - Part I Task - Using CREATE CREATE - Part II Task - Using INSERT Read Task - Using SELECT Update Task - Using UPDATE Delete - Part I Delete - Part II Task - Using DELETE

5. Optimizing Database Operations

Stored Procedures Task - Executing Stored Procedures DataReader vs DataSet DataAdapter & DataSet Task - Reading Tables using MySqlDataAdapter What's Next?

MySqlCommand Methods

Note

If you're unable to delete objects from the MySQL server, it is possible that the server is running in safe mode. To disable safe mode, you can run the following query: SET SQL_SAFE_UPDATES=0;.

Important Points

We use ExecuteNonQuery for commands which modify the database;
ExecuteReader and ExecuteScalar are for querying commands that retrieve data from the database;
ExecuteReader returns a MySqlDataReader object;
MySqlDataReader has a method called read() which reads the rows in a sequential manner; We need to Close() the MySqlDataReader object after use;
ExecuteScalar returns an object which can be type-casted into the appropriate data type.

1. The following command selects and returns all the students that have marks higher than 90, which command is the most appropriate for executing this query?

2. The following command selects and returns the name of the oldest student in the class, which command is the most appropriate for executing this query?

The following command selects and returns all the students that have marks higher than 90, which command is the most appropriate for executing this query?

Select the correct answer

ExecuteReader

ExecuteNonQuery

ExecuteScalar

The following command selects and returns the name of the oldest student in the class, which command is the most appropriate for executing this query?

Select the correct answer

ExecuteReader

ExecuteNonQuery

ExecuteScalar

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 3. Kapitel 8

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