Intermediate SQL Flashcards
A dictionary that you can use until you drop it
View
defines set of columns that uniquely identify row in a table only if the key values are not null.
Unique constraints
consists of sequence of query and/or update statement
Transaction
ensure that a value that appears in one relation (the referencing relation) for a give set of attributes also appears for a certain set of attributes in other relation (the referenced relation)
Referential integrity constraints
a combination of date and time.
timestamp
can specify that if a delete or update action on the referenced relation violates the constraint, then, instead of rejecting the action, the system must take steps to change the tuple in the referencing relation to restore constraint.
Foreign key clause
the time of day, in hours, minutes and seconds.
Time
ensure that changes made to the database by authorized users do not result in a loss of data consistency.
Integrity Constraints
Are virtual table formed by a query
View
Not updatable
View
Owned by database user and has the same name as that user
Schema
a operation that produces Cartesian product of two tables.
Cross Join
a join operation that allows you to specify a explicit join clause
Inner Join
a collection of database objects
Schema
It preserves the unmatched rows from the first (left) table, joining them with a NULL row in the shape of the second (right) table.
Left Outer Join
prohibits the insertion of a null value for the attribute.
Not Null
used to specify wide range of rules for the contents of a table
Check Constraints
are logical structure create by user
Schema Object
It preserves the unmatched rows from the first (right) table, joining them with a NULL in the shape of the first (left) table.
Right Outer Join
a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.
Index
a calendar date containing a (four-digit) year, month and day of the month.
Date
create implicit join clause for you based on the common columns in the two table being join.
Natural Join
