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  2. Prepared statement - Wikipedia

    en.wikipedia.org/wiki/Prepared_statement

    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.

  3. Merge (SQL) - Wikipedia

    en.wikipedia.org/wiki/Merge_(SQL)

    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.

  4. Database trigger - Wikipedia

    en.wikipedia.org/wiki/Database_trigger

    The scope of DDL triggers can be a database (CREATE TRIGGER name ON DATABASE ...) or the entire SQL Server instance (CREATE TRIGGER name ON ALL SERVER). When you use the entire instance, you can capture all events executed on commands that have server-level scope as well as any commands that have database-level scope in the SQL instance.

  5. SQL syntax - Wikipedia

    en.wikipedia.org/wiki/SQL_syntax

    CREATE creates an object (a table, for example) in the database, e.g.: CREATE TABLE example ( column1 INTEGER , column2 VARCHAR ( 50 ), column3 DATE NOT NULL , PRIMARY KEY ( column1 , column2 ) ); ALTER modifies the structure of an existing object in various ways, for example, adding a column to an existing table or a constraint, e.g.:

  6. Create, read, update and delete - Wikipedia

    en.wikipedia.org/wiki/Create,_read,_update_and...

    CRUD is also relevant at the user interface level of most applications. For example, in address book software, the basic storage unit is an individual contact entry. As a bare minimum, the software must allow the user to: [6] Create, or add new entries; Read, retrieve, search, or view existing entries; Update, or edit existing entries

  7. Second normal form - Wikipedia

    en.wikipedia.org/wiki/Second_normal_form

    To make the design conform to 2NF, it is necessary to have two relations. To create these relations: Remove the functionally dependent attributes in the partial dependencies of the first normal form relation. In this example, {Manufacturer country} is the functionally dependent attribute which will be removed.

  8. Weak entity - Wikipedia

    en.wikipedia.org/wiki/Weak_entity

    Consider a database that records customer orders, where an order is for one or more of the items that the enterprise sells. The database would contain a table identifying customers by a customer number (primary key); another identifying the products that can be sold by a product number (primary key); and it would contain a pair of tables describing orders.

  9. View (SQL) - Wikipedia

    en.wikipedia.org/wiki/View_(SQL)

    Views can make it easier to create lossless join decomposition. Just as rows in a base table lack any defined ordering, rows available through a view do not appear with any default sorting. A view is a relational table, and the relational model defines a table as a set of rows.