Faster access than browser!
20 relations: Alphabet (formal languages), Existential quantification, Extension (predicate logic), First-order logic, ISBL, Monoid, Multiset, Projection (set theory), Relation (database), Relational algebra, Restriction (mathematics), Select (SQL), Set (mathematics), Set theory, SQL, String (computer science), String operations, Subset, Tuple, Unary operation.
Alphabet (formal languages)
In formal language theory, a string is defined as a finite sequence of members of an underlying base set; this set is called the alphabet of a string or collection of strings.
New!!: Projection (relational algebra) and Alphabet (formal languages) · See more »
Existential quantification
In predicate logic, an existential quantification is a type of quantifier, a logical constant which is interpreted as "there exists", "there is at least one", or "for some".
New!!: Projection (relational algebra) and Existential quantification · See more »
Extension (predicate logic)
The extension of a predicatea truth-valued functionis the set of tuples of values that, used as arguments, satisfy the predicate.
New!!: Projection (relational algebra) and Extension (predicate logic) · See more »
First-order logic
First-order logic—also known as first-order predicate calculus and predicate logic—is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science.
New!!: Projection (relational algebra) and First-order logic · See more »
ISBL
ISBL (Information Systems Base Language) is the relational algebra notation that was invented for PRTV, one of the earliest database management systems to implement E.F. Codd's relational model of data.
New!!: Projection (relational algebra) and ISBL · See more »
Monoid
In abstract algebra, a branch of mathematics, a monoid is an algebraic structure with a single associative binary operation and an identity element.
New!!: Projection (relational algebra) and Monoid · See more »
Multiset
In mathematics, a multiset (aka bag or mset) is a modification of the concept of a set that, unlike a set, allows for multiple instances for each of its elements.
New!!: Projection (relational algebra) and Multiset · See more »
Projection (set theory)
In set theory, a projection is one of two closely related types of functions or operations, namely.
New!!: Projection (relational algebra) and Projection (set theory) · See more »
Relation (database)
In relational database theory, a relation, as originally defined by E. F. Codd, is a set of tuples (d1, d2,..., dn), where each element dj is a member of Dj, a data domain.
New!!: Projection (relational algebra) and Relation (database) · See more »
Relational algebra
Relational algebra, first created by Edgar F. Codd while at IBM, is a family of algebras with a well-founded semantics used for modelling the data stored in relational databases, and defining queries on it.
New!!: Projection (relational algebra) and Relational algebra · See more »
Restriction (mathematics)
In mathematics, the restriction of a function f is a new function f\vert_A obtained by choosing a smaller domain A for the original function f. The notation f is also used.
New!!: Projection (relational algebra) and Restriction (mathematics) · See more »
Select (SQL)
The SQL SELECT statement returns a result set of records from one or more tables.
New!!: Projection (relational algebra) and Select (SQL) · See more »
Set (mathematics)
In mathematics, a set is a collection of distinct objects, considered as an object in its own right.
New!!: Projection (relational algebra) and Set (mathematics) · See more »
Set theory
Set theory is a branch of mathematical logic that studies sets, which informally are collections of objects.
New!!: Projection (relational algebra) and Set theory · See more »
SQL
SQL (S-Q-L, "sequel"; Structured Query Language) is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).
New!!: Projection (relational algebra) and SQL · See more »
String (computer science)
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.
New!!: Projection (relational algebra) and String (computer science) · See more »
String operations
In computer science, in the area of formal language theory, frequent use is made of a variety of string functions; however, the notation used is different from that used for computer programming, and some commonly used functions in the theoretical realm are rarely used when programming.
New!!: Projection (relational algebra) and String operations · See more »
Subset
In mathematics, a set A is a subset of a set B, or equivalently B is a superset of A, if A is "contained" inside B, that is, all elements of A are also elements of B. A and B may coincide.
New!!: Projection (relational algebra) and Subset · See more »
Tuple
In mathematics, a tuple is a finite ordered list (sequence) of elements.
New!!: Projection (relational algebra) and Tuple · See more »
Unary operation
In mathematics, a unary operation is an operation with only one operand, i.e. a single input.
New!!: Projection (relational algebra) and Unary operation · See more »
Redirects here:
Projection (database), Projection in relational algebra.
References
[1] https://en.wikipedia.org/wiki/Projection_(relational_algebra)
