Cascading delete or cascading update operations that either delete a row containing a Primary Key or updates a Primary Key value referenced by Foreign Key columns in existing rows in other tables. On a cascading delete, all the rows whose Foreign Key values reference the deleted Primary Key value are also deleted. On a cascading update, all the Foreign Key values are updated to match the new Primary Key value.
CASE expression
A complex expression that handles multiple-branch conditional logic.
CAST
The CAST function converts data from one type to another and is based on the ANSI SQL-92 standard as opposed to the CONVERT function.
CHECK constraint
Defines what values are acceptable in a column. You can apply CHECK constraints to multiple columns, and you can apply multiple CHECK constraints to a single column. When a table is dropped, CHECK constraints are also dropped.
Client Network utility
The Client Network utility is used to manage the client net-libraries and define server alias names. It can also be used to set the default options used by DB-Library applications.
client/server
A physically or logically implemented system where a device or application called the server requests services or data from another device or application and the server fulfills the request.
clustered index
A clustered index in SQL Server is a type of index in which the logical order of key values determines the actual data rows; thereby the data rows are kept sorted. Using a clustered index causes the actual data rows to move into the leaf level of the index.
collation (sequence)
A set of rules that determines how data is compared, ordered, and presented. Character data is sorted using collation information, including locale, sort order, and case sensitivity.
column list
The column list, or select list, is the part of the SELECT statement that specifies the columns being accessed.
comment
Inline documentation used to explain what a set of T-SQL statements is doing. This is also a technique used to temporarily prevent statements from running for diagnostic and troubleshooting reasons; usually used in the sense "comment out."
constraint
A property assigned to a table column that prevents certain types of invalid data values from being placed in the column. For example, a UNIQUE or PRIMARY KEY constraint prevents you from inserting a value that is a duplicate of an existing value; a CHECK constraint prevents you from inserting a value that does not match a search condition; and NOT NULL prevents you from inserting a NULL value.
CREATE
A command used to create a database object, such as a view or stored procedure.
CREATE TRIGGER
Using the CREATE TRIGGER statement is the T-SQL way to create a trigger, but they can also be created using the Enterprise Manager. As with CREATE VIEW, you can specify useful arguments, such as WITH ENCRYPTION.
Current Activity window
The window view in the Enterprise Manager that enables you to see current processes, objects, and locks held by SQL Server.
cursor
A construct that holds a rowset from a SELECT statement, which can then be stepped through row by row for various operations.