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  2. SQL syntax - Wikipedia

    en.wikipedia.org/wiki/SQL_syntax

    Hire_Date > '2012-01-31' < Less than Bonus < 50000. 00 >= Greater than or equal Dependents >= 2 <= Less than or equal Rate <= 0. 05 [NOT] BETWEEN [SYMMETRIC] Between an inclusive range. SYMMETRIC inverts the range bounds if the first is higher than the second. Cost BETWEEN 100. 00 AND 500. 00 [NOT] LIKE [ESCAPE] Begins with a character pattern ...

  3. Range query (database) - Wikipedia

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

    A range query is a common database operation that retrieves all records where some value is between an upper and lower boundary. [1] For example, list all employees with 3 to 5 years' experience. Range queries are unusual because it is not generally known in advance how many entries a range query will return, or if it will return any at all.

  4. Select (SQL) - Wikipedia

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

    Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form:

  5. Relational algebra - Wikipedia

    en.wikipedia.org/wiki/Relational_algebra

    In 1998 Chris Date and Hugh Darwen proposed a language called Tutorial D intended for use in teaching relational database theory, and its query language also draws on ISBL's ideas. [10] Rel is an implementation of Tutorial D. Bmg is an implementation of relational algebra in Ruby which closely follows the principles of Tutorial D and The Third ...

  6. Set operations (SQL) - Wikipedia

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

    The following example EXCEPT query returns all rows from the Orders table where Quantity is between 1 and 49, and those with a Quantity between 76 and 100. Worded another way; the query returns all rows where the Quantity is between 1 and 100, apart from rows where the quantity is between 50 and 75.

  7. SQL - Wikipedia

    en.wikipedia.org/wiki/SQL

    SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...

  8. Relation (database) - Wikipedia

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

    Relation, tuple, and attribute represented as table, row, and column respectively. In database theory, a relation, as originally defined by E. F. Codd, [1] is a set of tuples (d 1,d 2,...,d n), where each element d j is a member of D j, a data domain. Codd's original definition notwithstanding, and contrary to the usual definition in ...

  9. Range query (computer science) - Wikipedia

    en.wikipedia.org/wiki/Range_query_(computer_science)

    Given a function that accepts an array, a range query (,) on an array = [,..,] takes two indices and and returns the result of when applied to the subarray [, …,].For example, for a function that returns the sum of all values in an array, the range query ⁡ (,) returns the sum of all values in the range [,].