| Previous | Contents | Index |
This example shows how to access the actual field data using field expressions.
| Example 15-26 Field Expressions in ASK TABLE FIELD |
|---|
open table cl: name 'sheerpower:samples\client'
do
clear
print at 1, 1:;
ask_fields
if _back or _exit then exit do
show_data
loop
close table cl
stop
routine ask_fields
do
if _error then set error off
print 'Field List: '; &
'ID, LAST, FIRST, MIDDLE, STREET, CITY, STATE, ZIP, PHONE'
print
line input 'Select fields to display': field_list$
if _back or _exit then exit do
for f = 1 to elements(field_list$)
field$ = element$(field_list$, f)
ask table cl, field #field$: number z
if z = 0 then
message error: 'Illegal field: '; field$
end if
next f
loop while _error
end routine
routine show_data
print
extract table cl
for f = 1 to elements(field_list$)
field$ = element$(field_list$, f)
print cl(#field$),
next f
print
end extract
delay
end routine
end
Field List: ID, LAST, FIRST, MIDDLE, STREET, CITY, STATE, ZIP, PHONE
Select fields to display? last,first,phone
Smith Sam (809) 555-8789
Kent Keith (619) 967-5021
Johnson Paul (619) 489-5551
Waters Wayne (619) 564-1231
Rodrigues Homero ( ) - 0
Donaldson George ( ) - 0
Errant Earl (408) 844-7676
Abott Al (202) 566-9892
Brock Bud (218) 555-4322
Cass Cathy (619) 743-8582
Porter Pete (619) 778-6709
Derringer Dale (818) 223-9014
Farmer Fred (305) 552-7872
|
ASK TABLE table_name, FIELD field_name: ACCESS str_var
|
ACCESS retrieves the access (read and write) rules for the specified field. This information tells if the field can be read and written to. N is normal--meaning the field can be read and written to if the structure is also "N"ormal. Depending on whether security levels have been set on the table and/or field, the letter can be in the range of A thru Z. Sheerpower defaults to N when the table is created and fields are defined.
| Example 15-27 ACCESS - Field Definition Item |
|---|
open table inv: name 'sheerpower:samples\invoice', access input ask table inv, field custnbr: access x$ print x$ close table inv end READ:N, WRITE:N |
ASK TABLE table_name, FIELD field_expr: APPLICATION str_var
|
APPLICATION returns a name of an application for the specified field in a string variable. This is optional information the user provides when the field is defined.
| Example 15-28 APPLICATION - Field Definition Item |
|---|
open table cl : name 'sheerpower:samples\client' ask table cl, field id: application str$ print str$ close table cl end REPORTING_ID |
ASK TABLE table_name, FIELD field_expr: ATTRIBUTES str_var
|
ATTRIBUTES returns the Sheerpower field semantics (NUM - number, UC - upper-case, etc.) for the specified field in a string variable.
Refer to Section 16.3.1.9, Semantics for detailed information on field attributes.
ASK TABLE table_name, FIELD field_expr: CHANGEABLE num_var
|
CHANGEABLE returns a value of TRUE or FALSE. If the field specified by field_expr can be changed, the value is TRUE. If the field cannot be changed, the value is FALSE.
| Example 15-29 CHANGEABLE - Field Definition Item |
|---|
open table cl: name 'sheerpower:samples\client' ask table cl, field id: changeable z ask table cl, field city: changeable z1 print z print z1 close table cl end 0 1 |
ASK TABLE table_name, FIELD field_expr: DATATYPE str_var
|
DATATYPE returns the field data type, such as CH (character), IN (integer), etc., in a string variable.
Refer to Section 16.3.1.4, Data Type for detailed information on field data types.
ASK TABLE table_name, FIELD field_expr: DESCRIPTION str_var
|
DESCRIPTION returns the description for the specified field in a string variable.
ASK TABLE table_name, FIELD field_expr: HEADING str_var
|
HEADING returns the report column heading for the specified field in a string variable. This is the heading that would appear in a Guided Query Language (GQS) report column.
ASK TABLE table_name, FIELD field_expr: HELP str_var
|
HELP returns the help text for the specified field in a string variable.
ASK TABLE table_name, FIELD field_expr: KEYED num_var
|
KEYED returns a value of TRUE or FALSE in a numeric variable. If the specified field is a key field, the value is TRUE. Otherwise, the value is FALSE.
ASK TABLE table_name, FIELD field_expr: LENGTH num_var
|
LENGTH returns the length of the specified field in a numeric variable.
ASK TABLE table_name, FIELD field_expr: NAME str_var
|
NAME returns the name of the specified field in a string variable.
ASK TABLE table_name, FIELD field_name: NULL int_var
|
If the specified field is NULL (i.e. contains no data), this statement returns TRUE. If the field is not NULL, the statement returns FALSE.
ASK TABLE table_name, FIELD field_expr: NUMBER num_var
|
NUMBER returns the field number of the specified field in a numeric variable. Fields are numbered sequentially. If the field does not exist, Sheerpower returns a value of 0.
ASK TABLE table_name, FIELD field_expr: OPTIMIZED num_var
|
OPTIMIZED returns a value of TRUE or FALSE in a specified numeric variable. If the key field in field_expr is optimized, the value is TRUE. Otherwise, the value is FALSE.
| Example 15-30 OPTIMIZED - Field Definition Item |
|---|
open table cl: name 'sheerpower:samples\client' ask table cl, field id: optimized z print z close table cl end 1 |
| Previous | Next | Contents | Index |