Tuple: Line
Properties: Columns
Relational tables
Domain: column legitimate worthy collection
Atomicity: an integral element in the set of domains
Relationship Example: Table a particular set of rows
Relational Mapping: Corresponding program design variables
Mapping relational schema: corresponding to the type definition programming; the sequence and its attribute domains
Examples mapping relation: Concepts variable value corresponding to a program designed to
Database schema: logical database design
Database instance: a snapshot of a time data in the database
Ultra Code: set of one or more attributes in a relationship that uniquely identifies the tuple
Candidate Code: any subset of the super size is not super code, this code is called super-minimum candidate code
Main Code: designer selects the candidate code used to distinguish the different tuples
The outer code: Mode another relation (r2) of the primary key attribute a relational schema (r1) appearing, r1 this property is referred to with reference to the reference relation is referred to as the outer code .r1 r2 outer code dependent, r2 called outer code It is referring to relations
Integrity constraints: primary key, foreign key, a non-integrity constraints waited in vain; prohibit any SQL database update destroy the integrity constraints
Referential integrity constraints: the reference value of any tuple in the relation on a specific attribute must be equal to the value of a tuple in a particular attribute is with reference to the relationship
Connecting operation: the two element combination relations into a single tuple and
Natural join operation: tuples from two relations, if the same value on the same property, then the tuple appears in results
Cartesian product operation:
Data Definition Language: define relationships mode, delete relations, relational schema modification
Integrity: Integrity constraint data definition language-defined data to meet the needs of
View: View defined data definition language
Data Manipulation Language: CRUD tuple
Transaction control:
Authorization:
Embedded and dynamic sql: