Tandem ENFORM 058057, Reference Manual

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ENFORM Terminology
Introduction
058057 Tandem Computers Incorporated
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By-items. Field names modified by the BY or BY DESC clauses described in Section 5.
The values of the fields are used to sort and group the query output.
Request-qualification. A condition or conditions that a data base element must meet
before it is selected to contribute to your query output. A request-qualification begins
with a WHERE keyword followed by a logical expression.
Compiler/report writer. The ENFORM process that compiles your query and writes a
report (if one is requested). The compiler/report writer issues error messages for
syntax errors. If no errors exist, the compiler/report writer passes your compiled
query specifications along with information obtained from the dictionary to the query
processor. After the query processor returns the retrieved data (in the form of the
target-records described later in this section), the compiler/report writer formats and
writes the report.
Dictionary. Physical files that contain information called record descriptions. A record
description provides ENFORM with information about the name of the record being
accessed, the name and data type of any fields within the record, the record and field
length, the name of any primary or alternate key fields, and the name of the physical
file associated with the record description. The dictionary is created by the Data
Definition Language (DDL) compiler from record descriptions written in DDL. The
dictionary must exist before your query specifications are processed. Refer to the Data
Definition Language (DDL) Programming Manual and the ENFORM User’s Guide for
more information about the dictionary.
Query processor. The ENFORM process that uses the information provided by the
compiler/report writer to retrieve information from the data base. The query
processor also performs other functions such as creating a new physical file and
transmitting records to a host language program. Creating a new physical file is
described with the FIND statement in Section 5 of this manual. The host language
interface is described in the ENFORM User’s Guide.
Target-records. The records built by the query processor from which your ENFORM
output is produced. The query processor returns the target-records to the
compiler/report writer if the ENFORM output is to be formatted and written as a
report.
Data base. The collection of physical files from which the query processor retrieves
data. Any physical file from which data is retrieved must be associated with the
record description obtained from the dictionary.