cerelace.xyz › how-to-create-a-view-in-mysql. The CREATE VIEW statement creates a new view, or replaces an existing view if the OR REPLACE clause is given. If the view does not exist, CREATE OR REPLACE. Syntax. The syntax for the CREATE VIEW statement in MySQL is: CREATE [OR REPLACE] VIEW view_name AS SELECT columns FROM tables [WHERE conditions];. ANYDESK FILE TRANSFER CMD
In this article, I am going to cover the following topics:. The database views are the virtual tables that are generated by the query output. The View does not store the physical data on the database. When we run a SELECT statement on a database view, it executes the query and populates the data from the underlying tables used to create a view.
The MySQL database views can be created using three algorithms. The create view statement is the following:. Now, let us create a database view. To populate the list, the query should be written as follows:. The following query is used to populate the data from the View. Suppose we want to add a rental duration column in a view, then the query should be written as follows:. As you can see in the above image, the new column RentalDuration has been added.
The queries that are used to create an updatable view must not have the following:. The updatable views must be created using a table that has a primary key column. These indicate that the required privileges must be held by the user who defined or invoked the view, respectively.
The permitted user values depend on the privileges you hold, as discussed in Section Also see that section for additional information about view security. For information about user auditing within views, see Section 6.
At view definition time, the view creator must have the privileges needed to use the top-level objects accessed by the view. For example, if the view definition refers to table columns, the creator must have some privilege for each column in the select list of the definition, and the SELECT privilege for each column used elsewhere in the definition. If the definition refers to a stored function, only the privileges needed to invoke the function can be checked.
The privileges required at function invocation time can be checked only as it executes: For different invocations, different execution paths within the function might be taken. Example: A view might depend on a stored function, and that function might invoke other stored routines. For example, the following view invokes a stored function f :. The privileges required for executing statements within f need to be checked when f executes. This might mean that privileges are needed for p1 or p2 , depending on the execution path within f.
The standard says that the definer of the view, which is the same as the owner of the view's schema, gets applicable privileges on the view for example, SELECT and may grant them. The DEFINER clause is an extension where the intent is to have what the standard has; that is, a permanent record of who defined the view. It affects how MySQL processes the view. For more information, see Section Some views are updatable.
For a view to be updatable, there must be a one-to-one relationship between the rows in the view and the rows in the underlying table. There are also certain other constructs that make a view nonupdatable. A generated column in a view is considered updatable because it is possible to assign to it.
For information about generated columns, see Section Data Definition Statements. Atomic Data Definition Statement Support. LIKE Statement. Silent Column Specification Changes. Secondary Indexes and Generated Columns.
Data Manipulation Statements. Parenthesized Query Expressions. The Subquery as Scalar Operand. Comparisons Using Subqueries. Restrictions on Subqueries. Transactional and Locking Statements. Statements That Cause an Implicit Commit. Restrictions on XA Transactions. Replication Statements. Functions which Configure the Source List.
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