Conocimientos En MySQL

1. ¿Cuál de los siguientes comandos se deben utilizar para crear una base de datos denominada "estudiante"?

CREATE ?I student

CREATE DATABASE student

DATABASE /student

DATABSE student

The correct answer is "CREATE DATABASE student". This command is used to create a new database named "estudiante".

Explanation

The correct answer is "CREATE DATABASE student". This command is used to create a new database named "estudiante".

2. ¿Cuál de los siguientes comandos se utiliza para eliminar toda la base de datos MySQL?

mysql_drop_database

mysql_drop_entiredb

mysql_drop_table

mysql_drop_tables

The correct answer is "mysql_drop_database". This command is used to delete or remove an entire database in MySQL. It is specifically designed to delete the entire database, including all its tables, data, and associated objects.

Explanation

The correct answer is "mysql_drop_database". This command is used to delete or remove an entire database in MySQL. It is specifically designed to delete the entire database, including all its tables, data, and associated objects.

3. ¿Qué enunciado SQL se utiliza para insertar nuevos datos en una base de datos?

INSERT INTO

UPDATE

ADD

INSERT NEW

The correct answer is "INSERT INTO". This SQL statement is used to insert new data into a database. It allows the user to specify the table name and the values to be inserted into the table. The INSERT INTO statement is commonly used in combination with the VALUES clause to provide the actual data to be inserted.

Explanation

The correct answer is "INSERT INTO". This SQL statement is used to insert new data into a database. It allows the user to specify the table name and the values to be inserted into the table. The INSERT INTO statement is commonly used in combination with the VALUES clause to provide the actual data to be inserted.

4. MySQL es...

Un lenguaje de programación

Una técnica para escribir programas confiables

Un sistema de gestión de bases de datos relacionales

Una base de datos

MySQL es un sistema de gestión de bases de datos relacionales. Esto significa que es una herramienta que permite organizar y administrar grandes cantidades de información de manera estructurada. MySQL permite crear, modificar y consultar bases de datos, así como gestionar la seguridad y el acceso a la información almacenada en ellas. Es ampliamente utilizado en aplicaciones web y es conocido por ser rápido, confiable y escalable.

Explanation

MySQL es un sistema de gestión de bases de datos relacionales. Esto significa que es una herramienta que permite organizar y administrar grandes cantidades de información de manera estructurada. MySQL permite crear, modificar y consultar bases de datos, así como gestionar la seguridad y el acceso a la información almacenada en ellas. Es ampliamente utilizado en aplicaciones web y es conocido por ser rápido, confiable y escalable.

5. En una clave primaria se permiten los valores nulos.

True

False

In a primary key, null values are not allowed. A primary key is a unique identifier for each record in a table, and it is used to enforce data integrity and ensure that each record can be uniquely identified. Null values represent missing or unknown data, and they are not allowed in a primary key because they would prevent the uniqueness constraint from being enforced. Therefore, the correct answer is false.

Explanation

In a primary key, null values are not allowed. A primary key is a unique identifier for each record in a table, and it is used to enforce data integrity and ensure that each record can be uniquely identified. Null values represent missing or unknown data, and they are not allowed in a primary key because they would prevent the uniqueness constraint from being enforced. Therefore, the correct answer is false.

6. Para usar MySQL en el equipo, ¿qué necesita?

FTP y Telnet

Una especie de programa de cliente para acceder a las bases de datos

Un navegador

HTML, PHP o Java

To use MySQL on a computer, you need a client program that allows you to access the databases. This client program acts as a bridge between the user and the MySQL server, allowing you to send queries and retrieve data from the databases. FTP and Telnet are not necessary for using MySQL, as they are protocols for file transfer and remote login, respectively. A browser is also not needed, as it is used for accessing websites and not for interacting with databases. HTML, PHP, and Java are programming languages used for web development and are not specifically required for using MySQL.

Explanation

To use MySQL on a computer, you need a client program that allows you to access the databases. This client program acts as a bridge between the user and the MySQL server, allowing you to send queries and retrieve data from the databases. FTP and Telnet are not necessary for using MySQL, as they are protocols for file transfer and remote login, respectively. A browser is also not needed, as it is used for accessing websites and not for interacting with databases. HTML, PHP, and Java are programming languages used for web development and are not specifically required for using MySQL.

7. Un valor NULL se trata como un espacio en blanco o 0.

True

False

A NULL value is treated as a blank or 0 value. This means that when a NULL value is encountered in a calculation or comparison, it is treated as if it were a blank or a 0. This is important to consider when working with databases or programming languages that use NULL values.

Explanation

A NULL value is treated as a blank or 0 value. This means that when a NULL value is encountered in a calculation or comparison, it is treated as if it were a blank or a 0. This is important to consider when working with databases or programming languages that use NULL values.

8. Dada una tabla de empleados (employees) de la siguiente manera:

emp_id	emp_name
1	Brush Cepillo
2	Jerrin Jerrin

¿qué valor será devuelto a partir de la siguiente consulta? "Select * from employees order by emp_name desc

Muestra los id de los empleados de menor a mayor

Muestra los id de los empleados de mayor a menor

Muestra la tabla completa ordenada de mayor a menor

Muestra sólo los nombres ordenados de menor a mayor

The query "Select * from employees order by emp_name desc" will return the complete table sorted in descending order based on the emp_name column. This means that the names of the employees will be displayed in alphabetical order from Z to A.

Explanation

The query "Select * from employees order by emp_name desc" will return the complete table sorted in descending order based on the emp_name column. This means that the names of the employees will be displayed in alphabetical order from Z to A.

9. ¿Qué función utiliza para obtener la hora actual en mysql?

getTime()

Time()

NOW()

La función correcta para obtener la hora actual en MySQL es Time(). Esta función devuelve la hora actual en el formato HH:MM:SS. getTime() no es una función válida en MySQL y NOW() devuelve la fecha y hora actual en el formato YYYY-MM-DD HH:MM:SS.

Explanation

La función correcta para obtener la hora actual en MySQL es Time(). Esta función devuelve la hora actual en el formato HH:MM:SS. getTime() no es una función válida en MySQL y NOW() devuelve la fecha y hora actual en el formato YYYY-MM-DD HH:MM:SS.

10. En una cláusula LIKE, ¿cómo se puede pedir cualquier valor que terminan en "QPT" por escrito?

LIKE %qpt

LIKE *qpt

LIKE %qpt%

LIKE @qpt

The correct answer is "LIKE %qpt%". This is because the "%" symbol is a wildcard character in SQL that represents zero or more characters. So, when we use "%qpt%", it means that we are looking for any value that has "qpt" as a substring, regardless of what characters come before or after it. The other options are incorrect because they either use the wrong wildcard character ("*") or do not include the "%" symbol to represent the wildcard.

Explanation

The correct answer is "LIKE %qpt%". This is because the "%" symbol is a wildcard character in SQL that represents zero or more characters. So, when we use "%qpt%", it means that we are looking for any value that has "qpt" as a substring, regardless of what characters come before or after it. The other options are incorrect because they either use the wrong wildcard character ("*") or do not include the "%" symbol to represent the wildcard.