How to create view in sql
How do you create a view in SQL?
To create a view, a user must have the appropriate system privilege according to the specific implementation. CREATE VIEW view_name AS SELECT column1, column2.. FROM table_name WHERE [condition]; You can include multiple tables in your SELECT statement in a similar way as you use them in a normal SQL SELECT query.
Why do we create view in SQL?
Views are virtual tables that can be a great way to optimize your database experience. Not only are views good for defining a table without using extra storage, but they also accelerate data analysis and can provide your data extra security.
What is view and create view in SQL?
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.
What is a view vs a table?
A view is a virtual table. A view consists of rows and columns just like a table. The difference between a view and a table is that views are definitions built on top of other tables (or views), and do not hold data themselves. If data is changing in the underlying table, the same change is reflected in the view.
How do I view SQL?
Using SQL Server Management Studio
- In Object Explorer, click the plus sign next to the database that contains the view to which you want to view the properties, and then click the plus sign to expand the Views folder.
- Right-click the view of which you want to view the properties and select Properties.
How do you create a database view?
Views in SQL are kind of virtual tables. A view also has rows and columns as they are in a real table in the database. We can create a view by selecting fields from one or more tables present in the database. A View can either have all the rows of a table or specific rows based on certain condition.
What Cannot be done on a view?
What cannot be done on a view? Explanation: In MySQL, ‘Views’ act as virtual tables. It is not possible to create indexes on a view. However, they can be used for the views that are processed using the merge algorithm.
How do I create a stored procedure?
To create the procedure, from the Query menu, click Execute. The procedure is created as an object in the database. To see the procedure listed in Object Explorer, right-click Stored Procedures and select Refresh. To run the procedure, in Object Explorer, right-click the stored procedure name HumanResources.
What is difference between stored procedure and function?
The function must return a value but in Stored Procedure it is optional. Functions can have only input parameters for it whereas Procedures can have input or output parameters. Functions can be called from Procedure whereas Procedures cannot be called from a Function.
What are triggers in SQL?
A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. SQL Server lets you create multiple triggers for any specific statement.
How does a stored procedure work?
A stored procedure is a prepared SQL code that you can save, so the code can be reused over and over again. So if you have an SQL query that you write over and over again, save it as a stored procedure, and then just call it to execute it.
Which is better stored procedure or function?
Stored procedures in SQL are easier to create and functions have a more rigid structure and support less clauses and functionality. By the other hand, you can easily use the function results in T-SQL. We show how to concatenate a function with a string. Manipulating results from a stored procedure is more complex.
What is the difference between SQL view and stored procedure?
Most simply, a view is used when only a SELECT statement is needed. Stored procedures hold the more complex logic, such as INSERT, DELETE, and UPDATE statements to automate large SQL workflows.
What is the purpose of stored procedure?
A Stored Procedure is pre-compiled collection of SQL statements and SQL command logic in stored in database. The main purpose of stored procedure is to hide direct SQL queries from the code and improve performance of database operations such as SELECT, UPDATE, and DELETE.
Why stored procedure is faster than query?
Each and every time a query is submitted, it has to run through the procedure of finding the execulation plan. Stored procedure on the other hand should be faster because the execution plan can be created and cached the moment the procedure is added or run for the first time is the assumption.
What is trigger explain with example?
Trigger: A trigger is a stored procedure in database which automatically invokes whenever a special event in the database occurs. For example, a trigger can be invoked when a row is inserted into a specified table or when certain table columns are being updated.
What is the benefit of stored procedure in SQL?
By grouping SQL statements, a stored procedure allows them to be executed with a single call. This minimizes the use of slow networks, reduces network traffic, and improves round-trip response time. OLTP applications, in particular, benefit because result set processing eliminates network bottlenecks.
Can you give an example of a stored procedure?
There can be a case when a stored procedure doesn’t returns anything. For example, a stored procedure can be used to Insert , delete or update a SQL statement. For example, the below stored procedure is used to insert value into the table tbl_students .
What is a procedure?
1a : a particular way of accomplishing something or of acting. b : a step in a procedure. 2a : a series of steps followed in a regular definite order legal procedure a surgical procedure. b : a set of instructions for a computer that has a name by which it can be called into action.
What are SQL functions?
A function is a set of SQL statements that perform a specific task. Next time instead of rewriting the SQL, you can simply call that function. A function accepts inputs in the form of parameters and returns a value. SQL Server comes with a set of built-in functions that perform a variety of tasks.
What are different types of SQL functions?
Types of SQL functions
- SQL Count function.
- SQL Sum function.
- SQL Avg function.
- SQL Max function.
- SQL Min function.
What are the basic commands of SQL?
There are five types of SQL commands: DDL, DML, DCL, TCL, and DQL.
- Data Definition Language (DDL) DDL changes the structure of the table like creating a table, deleting a table, altering a table, etc.
- Data Manipulation Language.
- Data Control Language.
- Transaction Control Language.
- Data Query Language.