access.selection.criteria Definition/Access: Verbs

access.selection.criteria

Command access.selection.criteria Definition/Access: Verbs
Applicable release versions: AP, R83
Category Access: Verbs (152)
Description determines which items are to be processed by Access and is designated by the "with" or "if" modifiers.

Without any "selection clauses" in an Access sentence, every item in the file is eligible for processing.

Compound selection clauses are formed with the "and" or "or" relational operators. When two clauses are connected by an "and", both conditions must evaluate to "true" for an item to be selected for processing. When two selection clauses are connected with an "or", or no relational operator is specified between selection clauses, either condition may evaluate to true for the item to be selected for processing.

The value specified in the "valuestring" clause must match exactly with the stored value for selection to occur. For example, in the sentence:

list entity with city = "irv" city

Only those items which contain "irv" in the "city" attribute are eligible for processing.

String searching:

Access permits the use of "string searching" (sometimes called "wild cards") which allow introducing variables into the selection criteria. For example, in the sentence:

list entity with city = "irv]" city

The "]" character specifies that any character(s) may follow the literal string, "irv". This means that both "irvine" and "irving" are selected. In the sentence:

list entity with name "[inc."

Any item whose "name" attribute ended with "inc." is eligible for processing.

The "bracket" ("string searching") characters may also state an "including" or "containing" condition, as in the form:

list entity with name = "[pick]"

Which includes in the report any item whose "name" attribute contains the string "pick". This includes "Pick Systems", "Movenpick Restauraunts" and "The First Pick".
Syntax
Options
Example
list entity with name "ar]" name

In this selection criteria, only those items whose "name" field 
begins with "ar" are selected. 

list entity with name "mi]" and with phone "804]"

This example shows two selection clauses connected with an "and", 
which means that both conditions must be evaluated as true in order for the 
items to be selected for processing.

list entity with name "re]" or with city "irv]" name city

This example shows a mutually exclusive set of selection crtieria connected 
with an "or". Either condition evaluating to true will accept the 
item for processing. That is, if the "name" attribute begins with 
"ar", or the "city" attribute begins with "irv", 
the item will be selected for output.

list entity with name "ar]" and with city "irv]" or with 
city "san]" and with contact "[joe]"

There is virtually no limit to compound selection criteria in an Access 
sentence, with the exception of the fact that Access limits a sentence to a 
maximum of 9 "and" clauses.
Purpose
Related access.selection.processor
wildcards
access.with
tcl.sortc
access.without
access.sreformat
access.t-dump
access.s-dump
access.sort
access.sselect
access.t-load
access.sort-label
access.stat
access.sum
access.select
access.nselect
access.introduction
tcl.ld
access.list-label
access.count
access.list-item
access.list
access.verbs
collation.order
access.itemlist