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This language that enable user to access or manipulate data as ORGANIZED by appropriate data model.

•  Procedural DML or LOW level: DML requires a user to SPECIFY what data are needed and how to get those data.
•  Non-Procedural DML or High level: DML requires a user to specify what data are needed WITHOUT specifying how to get those data.

This language that enable user to access or manipulate data as organized by appropriate data model.

It is the NUMBER of ENTITY TYPE PARTICIPATING.

It is the number of entity type participating.

RELATIONSHIP type defines a SET of associations or a relationship set among a given set of ENTITY TYPES.

Relationship type defines a set of associations or a relationship set among a given set of entity types.

The COLLECTION (or SET) of SIMILAR RELATIONSHIPS.

The collection (or set) of similar relationships.

A simple view can be thought of as a subset of a table. It can be USED for retrieving data, as well as updating or DELETING rows. Rows updated or deleted in the view are updated or deleted in the table the view was created with. It should also be noted that as data in the original table changes, so does data in the view, as VIEWS are the way to look at part of the original table. The RESULTS of using a view are not permanently stored in the database. The data ACCESSED through a view is actually constructed using standard T-SQL select command and can come from one to many different base tables or even other views.

A simple view can be thought of as a subset of a table. It can be used for retrieving data, as well as updating or deleting rows. Rows updated or deleted in the view are updated or deleted in the table the view was created with. It should also be noted that as data in the original table changes, so does data in the view, as views are the way to look at part of the original table. The results of using a view are not permanently stored in the database. The data accessed through a view is actually constructed using standard T-SQL select command and can come from one to many different base tables or even other views.

A TRIGGER is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. TRIGGERS are stored in and managed by the DBMS. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or executed; the DBMS AUTOMATICALLY fires the trigger as a result of a data modification to the associated table. Triggers can be viewed as SIMILAR to stored procedures in that both consist of procedural logic that is stored at the database level. Stored procedures, however, are not event-drive and are not attached to a specific table as triggers are. Stored procedures are explicitly executed by invoking a CALL to the procedure while triggers are implicitly executed. In addition, triggers can ALSO execute stored procedures.

A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. Triggers are stored in and managed by the DBMS. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or executed; the DBMS automatically fires the trigger as a result of a data modification to the associated table. Triggers can be viewed as similar to stored procedures in that both consist of procedural logic that is stored at the database level. Stored procedures, however, are not event-drive and are not attached to a specific table as triggers are. Stored procedures are explicitly executed by invoking a CALL to the procedure while triggers are implicitly executed. In addition, triggers can also execute stored procedures.

1NF: Eliminate Repeating Groups Make a SEPARATE table for each set of related attributes, and give each table a primary key. Each field contains at most one value from its attribute domain.

2NF: Eliminate Redundant Data If an attribute depends on only part of a multi-valued key, remove it to a separate table.

3NF: Eliminate Columns Not Dependent On Key If attributes do not contribute to a description of the key, remove them to a separate table. All attributes must be directly dependent on the primary key.

BCNF: Boyce-Codd Normal Form If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.

4NF: Isolate Independent Multiple RELATIONSHIPS No table may CONTAIN two or more 1:n or n:m relationships that are not directly related.

5NF: Isolate Semantically Related Multiple Relationships There may be practical constrains on information that justify separating logically related many-to-many relationships.

ONF: Optimal Normal Form A model limited to only simple (elemental) facts, as expressed in OBJECT Role Model notation.

DKNF: Domain-Key Normal Form A model free from all modification anomalies. Remember, these normalization guidelines are cumulative. For a database to be in 3NF, it must first fulfill all the criteria of a 2NF and 1NF database.

1NF: Eliminate Repeating Groups Make a separate table for each set of related attributes, and give each table a primary key. Each field contains at most one value from its attribute domain.

2NF: Eliminate Redundant Data If an attribute depends on only part of a multi-valued key, remove it to a separate table.

3NF: Eliminate Columns Not Dependent On Key If attributes do not contribute to a description of the key, remove them to a separate table. All attributes must be directly dependent on the primary key.

BCNF: Boyce-Codd Normal Form If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.

4NF: Isolate Independent Multiple Relationships No table may contain two or more 1:n or n:m relationships that are not directly related.

5NF: Isolate Semantically Related Multiple Relationships There may be practical constrains on information that justify separating logically related many-to-many relationships.

ONF: Optimal Normal Form A model limited to only simple (elemental) facts, as expressed in Object Role Model notation.

DKNF: Domain-Key Normal Form A model free from all modification anomalies. Remember, these normalization guidelines are cumulative. For a database to be in 3NF, it must first fulfill all the criteria of a 2NF and 1NF database.

RELATIONAL Data BASE Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained ACROSS and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. INTERDEPENDENCIES among these tables are expressed by data values rather than by pointers. This allows a high degree of data independence. An RDBMS has the capability to RECOMBINE the data items from different files, providing powerful tools for data usage.

Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers. This allows a high degree of data independence. An RDBMS has the capability to recombine the data items from different files, providing powerful tools for data usage.