enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Primary key - Wikipedia

    en.wikipedia.org/wiki/Primary_key

    In the relational model of databases, a primary key is a designated attribute that can reliably identify and distinguish between each individual record in a table.The database creator can choose an existing unique attribute or combination of attributes from the table (a natural key) to act as its primary key, or create a new attribute containing a unique ID that exists solely for this purpose ...

  3. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    An index may be declared as UNIQUE, which creates an implicit constraint on the underlying table. Database systems usually implicitly create an index on a set of columns declared PRIMARY KEY, and some are capable of using an already-existing index to police this constraint.

  4. Relational database - Wikipedia

    en.wikipedia.org/wiki/Relational_database

    The primary keys within a database are used to define the relationships among the tables. When a PK migrates to another table, it becomes a foreign key (FK) in the other table. When each cell can contain only one value and the PK migrates into a regular entity table, this design pattern can represent either a one-to-one or one-to-many relationship.

  5. Table (database) - Wikipedia

    en.wikipedia.org/wiki/Table_(database)

    In a database, a table is a collection of related data organized in table format; consisting of columns and rows. In relational databases, and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being the unit where a row and column intersect. [1]

  6. Identity column - Wikipedia

    en.wikipedia.org/wiki/Identity_column

    An identity column differs from a primary key in that its values are managed by the server and usually cannot be modified. In many cases an identity column is used as a primary key; however, this is not always the case. It is a common misconception that an identity column will enforce uniqueness; however, this is not the case. If you want to ...

  7. PL/SQL - Wikipedia

    en.wikipedia.org/wiki/PL/SQL

    This returned value may be a single scalar value (such as a number, date or character string) or a single collection (such as a nested table or array). User-defined functions supplement the built-in functions provided by Oracle Corporation. [6] The PL/SQL function has the form:

  8. Today's Wordle Hint, Answer for #1255 on Monday, November 25 ...

    www.aol.com/todays-wordle-hint-answer-1255...

    This color is made by mixing three primary colors: red, yellow and blue. OK, that's it for hints—I don't want to totally give it away before revealing the answer!

  9. Insert (SQL) - Wikipedia

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

    Using a SELECT statement after the INSERT statement with a database-specific function that returns the generated primary key for the most recently inserted row. For example, LAST_INSERT_ID() for MySQL. Using a unique combination of elements from the original SQL INSERT in a subsequent SELECT statement.