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Multiple statements or multi queries must be executed with mysqli_multi_query(). The individual statements of the statement string are separated by semicolon. Then, all result sets returned by the executed statements must be fetched. The MySQL server allows having statements that do return result sets and statements that do not return result ...
Major DBMSs, including SQLite, [5] MySQL, [6] Oracle, [7] IBM Db2, [8] Microsoft SQL Server [9] and PostgreSQL [10] support prepared statements. Prepared statements are normally executed through a non-SQL binary protocol for efficiency and protection from SQL injection, but with some DBMSs such as MySQL prepared statements are also available using a SQL syntax for debugging purposes.
Each Federated table that is defined there is one .frm (data definition file containing information such as the URL of the data source). The actual data can exist on a local or remote MySQL instance. To create a Federated table, one has to specify a URL in the "CONNECTION" string:
A derived table is the use of referencing an SQL subquery in a FROM clause. Essentially, the derived table is a subquery that can be selected from or joined to. The derived table functionality allows the user to reference the subquery as a table. The derived table is sometimes referred to as an inline view or a subselect.
Some database implementations adopted the term upsert (a portmanteau of update and insert) to a database statement, or combination of statements, that inserts a record to a table in a database if the record does not exist or, if the record already exists, updates the existing record.
Additionally, stored procedures may be invoked through a JDBC connection. JDBC represents statements using one of the following classes: Statement – the Statement is sent to the database server each and every time. In other words, the Statement methods are executed using SQL statements to obtain a ResultSet object containing the data. [9]
Unlike ordinary base tables in a relational database, a view does not form part of the physical schema: as a result set, it is a virtual table [1] computed or collated dynamically from data in the database when access to that view is requested.
A common table expression, or CTE, (in SQL) is a temporary named result set, derived from a simple query and defined within the execution scope of a SELECT, INSERT, UPDATE, or DELETE statement. CTEs can be thought of as alternatives to derived tables ( subquery ), views , and inline user-defined functions.