Optional SQL and DATATRIEVE formatting clauses allow you to
modify data displays or query characteristics for interactive SQL
users, DATATRIEVE users, or both. The optional formatting clauses
(QUERY NAME and EDIT STRING) and DATATRIEVE clauses (QUERY HEADER
and DEFAULT VALUE) can be used with the following statements:
o CREATE TABLE
o CREATE DOMAIN
o CREATE VIEW
o ALTER TABLE
o ALTER DOMAIN
The following diagram shows the format for these clauses:
sql-and-dtr-clause =
-+-> QUERY HEADER IS -+> <quoted-string> +-------------------+->
| +------ / <--------+ |
+-> EDIT STRING IS <quoted-string> -------------------------+
| |
+-> QUERY NAME FOR -+-> DTR --------+-> IS <quoted-string> -+
| +-> DATATRIEVE -+ |
+-> DEFAULT VALUE FOR -+-> DTR --------+-> IS literal ----+
+-> DATATRIEVE -+
o A query header specifies a string, enclosed in quotation
marks, that interactive SQL or DATATRIEVE displays in place
of the column name when it retrieves values from a column.
Query headers allow you to specify descriptive headings for
columns.
Both interactive SQL and DATATRIEVE display any query headers
you specify in SQL definitions.
o An edit string specifies a string, enclosed in quotation
marks, that controls how interactive SQL or DATATRIEVE formats
the display of values in a column.
Both interactive SQL and DATATRIEVE use edit strings you
specify in SQL definitions to control display formatting for
those definitions.
DATATRIEVE recognizes columns with null values and displays
them according to the edit string for the missing value.
o A query name specifies a string, enclosed in quotation marks,
that you can use instead of the column name when formulating
DATATRIEVE queries. Query names are useful for abbreviating
long column names in DATATRIEVE queries.
SQL does not recognize query names in interactive queries; the
QUERY NAME clause is useful only when you use DATATRIEVE to
retrieve the data.
o If you specify a default value for a column and do not specify
that column in a DATATRIEVE STORE or MODIFY statement,
DATATRIEVE stores the default value specified in the SQL
definition.
SQL does not recognize default values in INSERT or UPDATE
statements; the DEFAULT VALUE clause is useful only when you
use DATATRIEVE STORE or MODIFY statements.
Additional Information:
explode
extract