The answer to this is D. From the name itself, you can already make a guess on what the union clause can do. It has the ability to combine two different statements. Once these statements are combined, it will form a set that will be unique of the two statements that are combined together.
This also has the ability to get rid of the duplicated in the set if in case there are any. Duplicates may cause problems with combining statements in the long run. Some get confused with the union SQL and JOIN. JOIN will form answers regarding the relationships between the statements that are given and not the statements themselves.
Python is one of the most widely recognized scripting languages. Python is a programming language for high level general-purpose, which can be used in the development of websites, web applications, and even desktop GUI. This language was created in the 1980s so that it could be effectively used to teach programming. Python is very easy to learn, and it is also easy to read due to its flexibility. And it contains a lot of features that make it very useful.
SQL, on the other hand, is the short form of Structured Query Language. SQL is used to make entry into the database so as to be able to perform some manipulation in the database. This structured language can be used to make your needs known to the database. The database is a collection of related information in a regular structure. Your contact directory is an example of a database. Structured query language was created by IBM.
There are different clauses and tools that are used to modify columns and rows in order to edit tables as you need. Each has a precise function and as the names aren’t self-exploratory, you need to learn their uses in order to work them properly. Not only this, you may need to practice them thoroughly as well.
For instance, the AS SQL clause is a special tool that is used to change the name of a column in the result set. It can also be used to give heading to different columns in order to ensure optimal editing and performance.
MS SQL Server and Oracle are database management system designed to manage message processing. MS SQL is a database management system designed by Microsoft, Oracle is designed by Oracle corporation. They are very useful in performing any kind of online transaction, they are used for bills payment and even for shopping. However, there are some differences between MS SQL and Oracle. The first difference between MS SQL and Oracle is on the complexity of different syntaxes which are being used by the two database management system.
MS SQL makes use of simple and not too complex syntaxes for the smooth operation of the system. While Oracle uses relatively complex syntaxes for efficient service delivery. MS SQL has a great costumer service, there are a lot of explanations which have been made on the system so that users will not run into errors, while Oracle provides just little information about some things on the system. Once you finish a transaction on MS SQL, all your records will be cleared, while records on Oracle are left untouched until they get a Commit command.
SQL is the most widely used database language. SQL is a domain specific language used in programming and designed for managing data held in a relational database management system. It is useful in handling structured data where there are relations between different variables of the data. SQL offers two main advantages over the older read/write API's. It introduced the concept of accessing many records with one single command.
SQL eliminates the need to specify how to reach a record, with or without an index. SQL may be classified as sublanguages. The scope of SQL includes data, manipulation, data definition, and data control. It is a language, and it includes procedural elements.
The correct answer is B. When trying to select all the records from a table named "Persons" where the value of the column "FirstName" starts with an 'a' with SQL, SELECT FROM Persons WHERE FirstName LIKE a%. This answer is from the SQL Practice Test section.
SQL is a version of computing language used to communicate with databases in order to perform different tasks. These tasks can range from creating different folders for different clients to any other kind of data organization task. This is commonly used in companies which need to sort large amounts of data or information.
Take note that you want to gather information about the total number of orders. This means that you need to choose the select count from sales which is letter B in the choices. This will allow you to select all of the orders that you may need to highlight or check.
This is a very helpful command when you want to check if all of the orders are accounted for or if you did not miss any order from the ones that you have already input. You will use select AVG from sales if you want to know more about the average of the sales you have received for a certain time period. You will use Select SUM from sales if you want to know the amount that you made based on the number of sales.
This is the correct answer.
SELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id HAVING MIN(salary) <5000 AND MAX(salary) >15000.