Progress
Language Reference
SET Statement
Requests input, and then puts the data in the screen buffer frame and in the specified fields or variables. The SET statement is a combination of these statements:
DATA MOVEMENT
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SYNTAX
STREAM stream
Specifies the name of a stream. If you do not name a stream, Progress uses the unnamed stream. See the DEFINE STREAM Statement reference entry in this book and the chapter on alternate I/O sources in the Progress Programming Handbook for more information on streams.
UNLESS-HIDDEN
Restricts SET to fields whose HIDDEN attribute is FALSE.
field
Represents the name of the field or variable whose value you want to store in the screen buffer and in the field or variable.
In the case of array fields, array elements with constant subscripts are treated as any other field. Array fields with no subscripts are expanded as though you typed in the implicit elements. See the DISPLAY Statement reference entry for information on how Progress handles array fields with expressions as subscripts.
view-as-phrase
Specifies the widget used to represent the field. For more information on view-as-phrase, see the VIEW-AS Phrase reference entry.
format-phrase
Specifies one or more frame attributes for a field, variable, or expression. For more information on format-phrase, see the Format Phrase reference entry.
WHEN expression
Sets the field only when expression has a value of TRUE. An expression is a field name, variable name, or expression whose value is logical.
TEXT
Defines a group of character fields or variables (including array elements) to use automatic word wrap. The TEXT option works with character fields only. When you insert data in the middle of a TEXT field, Progress wraps data that follows into the next TEXT field, if necessary. If you delete data from the middle of a TEXT field, Progress wraps data that follows into the empty area. If you enter more characters than the format for the field allows, Progress discards the extra characters. The character fields must be in the x(n) format.
A blank in the first column of a line marks the beginning of a paragraph. Lines within a paragraph are treated as a group and will not wrap into other paragraphs.
Table 39 lists the keys you can use within a TEXT field, and their actions.
In this procedure, the s-com, or Order Comments field is a TEXT field. Run the procedure and enter text in the field to see how the TEXT option works.
field = expression
Indicates that the value of field is determined by evaluating the expression rather than having it entered on the screen or from a file. An assignment statement is embedded within the SET statement.
constant AT n
A constant value that you want to display in the frame. The n is the column in which you want to start the display.
constant TO n
A constant value that you want to display in the frame. The n is the column in which you want to end the display.
^
Tells Progress to ignore an input field when input is being read from a file. Also, the following statement reads a line from an input file and ignores that line.
This is an efficient way to skip over lines.
SPACE [ ( n ) ]
Identifies the number (n) of blank spaces to insert after the expression on the display. The n can be 0. If the number of spaces you specify is more than the spaces left on the current line of the frame, Progress starts a new line and discards any extra spaces. If you do not use this option or do not use n, Progress inserts one space between items in the frame.
SKIP [ ( n ) ]
Identifies the number (n) of blank lines to be inserted after the expression is displayed. The n can be 0. If you do not use this option, a line is not skipped between expressions only if they do not fit on one line. If you use the SKIP option, but do not specify n, or if n is 0, a new line is started unless it is already at the beginning of a new line.
GO-ON ( keylabel . . . )
Tells Progress to take the GO action when the user presses any of the keys listed. The keys you list are used in addition to keys that perform the GO action by default or because of ON statements. When you list a key label in the GO-ON option, you use the keyboard label of that key. For example, if you want Progress to take the GO action when the user presses F1, you use the statement GO-ON(F1). If you list more than one key, separate them with spaces, not commas, as in GO-ON( F1 RETURN ).
frame-phrase
Specifies the overall layout and processing properties of a frame. For more information on frame-phrase, see the Frame Phrase reference entry.
editing-phrase
Identifies processing to take place as each keystroke is entered. This is the syntax for the editing-phrase.
For more information on editing-phrase, see the EDITING Phrase reference entry.
record
Represents the name of a record buffer. All of the fields in the record, except those with the data type RECID and ROWID, are processed exactly as if you set each individually. The record you name must contain at least one field.
To use SET with a record in a table defined for multiple databases, you must qualify the record’s table name with the database name. See the Record Phrase reference entry for more information.
NO-ERROR
Specifies that any errors that occur in the attempt to set the value are suppressed. After the SET statement completes, you can check the ERROR-STATUS system handle for information on any errors that occurred.
EXCEPT field
Affects all fields except those fields listed in the EXCEPT phrase.
EXAMPLESThe
r-set.p
procedure reads each item record, displays the item-num and lets the user enter information for the item-name, on-hand, allocated, and price fields. When you run this procedure, notice that it does not display existing values for the item-name, on-hand, allocated, and price fields.
On each iteration of the block, the FOR EACH statement reads a single record into the item record buffer. The DISPLAY statement moves the item-num from the record buffer to the screen buffer where you can see it. The SET statement prompts for data, stores the data in screen buffers, and moves the data to the record buffer, overwriting whatever is already there. Therefore, even though the item-name, on-hand, allocated, and price fields are put into the item record buffer by the FOR EACH statement, you never see the values for those fields.
The
r-set2.p
procedure displays the cust-num, name, and credit-limit for a customer and lets you change the credit-limit field. The HELP option in the SET statement displays help information at the bottom of the screen when you are changing the credit-limit. The VALIDATE option in the SET statement makes sure that the credit-limit value is greater than 0. If it isn’t, VALIDATE displays the message “Invalid credit limit.”
After you modify credit-limit, the procedure creates an order for the customer and assigns the customer.cust-num value to the cust-num field in the order record. The SET statement lets you enter information for the order-num and ship-date fields. The VALIDATE option in the SET statement makes sure that the ship date is greater than TODAY.
NOTES
- If any field is a field in a database record, the SET statement upgrades the record lock condition to EXCLUSIVE-LOCK before updating the record.
- If any field is part of a record retrieved with a field list, the SET statement rereads the complete record before updating it.
- SET does not move data into the field or variable if there is no data in the corresponding screen field. There is data in a screen field if a DISPLAY of the field was done or if you enter data into the field. If you set a field or variable that has not been DISPLAYed in the frame and key in blanks, then the field or variable is not changed because the screen field is changed only if the data differs from what was in the frame field.
- When Progress compiles a procedure, it designs all the frames used by that procedure. When you run the procedure, the SET statement puts data into those fields.
- In a SET statement, Progress first prompts for all specified fields and then assigns the values of those fields, moving from left to right. During this left to right pass of the field list, Progress processes embedded assignments (field = assignment) as it encounters them.
- If you are getting input from a device other than the terminal, and the number of characters read by the SET statement for a particular field or variable exceeds the display format for that field or variable, Progress returns an error. However, if you are setting a logical field that has a format of y/n and the data file contains a value of YES or NO, Progress converts that value to “y” or “n”.
- If you type blanks into a field in which data has never been displayed, the ENTERED function returns FALSE and the SET or ASSIGN statement does not update the underlying field or variable. Also, if Progress has marked a field as entered, and the SET statement prompts for the field again and you do not enter any data, Progress no longer considers the field an entered field.
- If you use a single qualified identifier with the SET statement, the Compiler first interprets the reference as dbname.tablename. If the Compiler cannot resolve the reference as dbname.tablename, it tries to resolve it as tablename.fieldname.
When using SET to set fields, you must use table names that are different from field names to avoid ambiguous references. See the Record Phrase reference entry for more information.
- The SET statement causes the ASSIGN and WRITE events to occur and fires all related database ASSIGN and WRITE triggers. The ASSIGN triggers execute before the WRITE triggers and after the field is actually updated. The WRITE triggers only execute if the ASSIGN triggers do not return an error. If an ASSIGN trigger fails (or executes a RETURN statement with the ERROR option), the SET statement is undone. This means that any changes to the database from that SET statement are backed out. If the SET statement occurs within a transaction, any changes to variables, worktable fields, and temporary table fields are also undone unless they are defined with the NO-UNDO option. Also, if a WRITE trigger fails (or executes a RETURN statement with the ERROR option), the SET statement is undone. See the Progress Programming Handbook for more information on database triggers.
SEE ALSO
DEFINE STREAM Statement, EDITING Phrase, Format Phrase, Frame Phrase, PROMPT-FOR Statement, UPDATE Statement
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