Category: Commands

Locates a particular member of a result set and makes it the current member.

Syntax

LOCATE [num] [set] [WHERE clause]

Parameters

Comments

LOCATE starts searching at the current member of the set. The last member located becomes the current member of set. The system variable $Located is set to the number of members located, indicating the number of members in the result set.

The WHERE clause can be used to logically limit the members located.

Example

find all employees where location=”Detroit” -> DetroitSet

locate DetroitSet where FirstName=”John” and LastName=”Smith”

locate 2 DetroitSet where FirstName=”John” and LastName=”Smith”

Because LOCATE starts with the current member of any set it searches, the current member after the last LOCATE command is the third record containing the name John Smith.

find all Employees where LastName=”Smith” -> Smiths

locate all where FirstName=”John”

output $located

compute all Employees where LastName=”Smith” and FirstName=”John” valuate (“”)

output $membercount

find all Employees where LastName=”Smith” and FirstName=”John”

output $setcount

All three of the preceding examples determine how many employees have the name John Smith.

while

locate DetroitSet where LastName=”Smith” and FirstName=”John”

if $located = 0

  return    % checks if done

endif

ProcessEmp ( )  % program to process this John Smith

endwhile

Each John Smith record in the designated set is processed.

See Also

BOTTOM

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NEXT

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UP

Ends execution of an application program and returns to the “previous” command level.

Syntax

RETURN [TO procedure]

Parameters

Comments

The RETURN command stops execution of the current procedure.

If a TO clause is omitted, execution control returns to the calling procedure (the “parent”) at the command immediately following the call that started execution of the current procedure.

If a TO clause is used, execution control returns to the specified procedure, provided that it is found along the chain of procedures that are “ancestors” of the current procedure. Execution resumes at the command immediately following the call that started execution of the offspring procedure in the current chain. If the specified procedure is not found along the chain of ancestors, execution control returns to the main prompt level.

If the RETURN command is entered at the main prompt level, the application session is ended (just as if a BYE command had been issued).

Example

To return control from the current procedure to the calling procedure when a FIND command returns an empty result set, enter

find all Employees where Salary > 10000

if $setcount = 0

 return

endif

To return to a grandparent procedure if a FIND command returns an empty result set, enter

01 procedure Grandparent ( )

02  Parent ( )        % goes to line 20

   … more commands …

18 endprocedure

19 %————————————————-

20 procedure Parent ( )

21  Child ( )        % goes to line 35

   … more commands …

33 endprocedure

34 %————————————————-

35 procedure Child ( )

36  find all Employees where Salary > 10000

37  if $setcount = 0

38    return to Grandparent  % goes to line 03

39  endif

   … more commands …

50 endprocedure

See Also

BYE

SET FLOW

STOP

TRANSACTION

TRANSFORM

Performs a Boolean AND of two logic expressions.

Syntax

expression1 AND expression2

Parameters

Return Value

Logical, as follows:

Comments

This AND is not the same as the AND used with the BETWEEN operator.

Example

ClaimType = ‘Auto’ and DamageCost > 3000 and LastName= ‘Andretti’

This Boolean expression is logically true only when the insurance claim type is Auto, the cost of the damage is greater than 3,000, and the last name of the person making the claim is Andretti. Otherwise, the Boolean expression is logically false.

See Also

[NOT] BETWEEN

NOT

XOR

OR

IN

Specifies the fields that are selected for a report

Syntax

DETAIL LINE [colheadings] [GRAPHIC [TEMPLATE name]] reportitem [:format:] [WHERE clause]

Parameters

Comments

The DETAIL LINE command is executed for every record of the set specified in the REPORT FROM command.

The column headings for all reportitems specified in the DETAIL LINE command are displayed, subject to any colheadings specification.

Only one detail line is produced for each record of the report set. If more than one DETAIL LINE command is used in a report specification, the DETAIL LINE command that is executed for a particular record in the report set is the first DETAIL LINE without a WHERE clause, or the first DETAIL LINE whose WHERE clause is true for that record.

For more information on format, see Available Format Options.

See Also

Boolean Expressions

Conditional Expressions

BREAK (Reports)

COLUMN BREAK

How to Use The Report Generator

How To Use Value Expressions

Presents online help information.

Syntax

HELP [topic]

Parameters

For files that invoke the winhelp executable

Note: For Explorer-style hypertext Help files, topic is a character string or a number, or an expression that evaluates to a character string or a number which identifies a particular help topic in the help file. It invokes the name of one of the .html files that were used to build the . chm file.

Comments

The HELP command displays online help about a given topic. By default, the command accesses the help file, ZDL.CHM, in the directory containing the software. To use another help file, set the system variable $ HelpFile to the name of the desired help file.

In the Windows environment, the HELP command determines, based on the extension of the help file, whether to invoke the Internet Explorer’s hypertext help viewer ( hh.exe) or to invoke the Windows help driver ( winhelp.exe) to display the help topics.

Winhelp help files

If the help topic is specified as a character string, the HELP command passes the string to the help driver as a keyword. If an exact match is not found, the help driver displays a warning message, following the topic search window.

If the character string contains the pattern-matching wildcard character $, HELP passes the string to the help driver, up to the first $ character, as a keyword prefix. Keywords that match the prefix are displayed in a topic search window for selection.

If the help topic is specified as a number (any numeric data type), HELP passes the number to the help driver as a topic identifier. If the identifier is invalid, the help driver displays a warning message, followed by the topic search window.

If no help file can be found, the software raises an error.

Hypertext help files

The hypertext help viewer accepts only strings as topic names and they must match the html files that were used to build the . chm file.

See Also

$HelpFile

Starts and defines a procedure.

Syntax

PROCEDURE procname ([IN|OUT|INOUT] parm) [LOCAL (var)]

Parameters

Comments

PROCEDURE declares the start of a procedure program. (A procedure program can have many local procedures, but only one main procedure.)

The call to the procedure must contain a corresponding expression for each parameter. The order of the expressions in the call must match the order of the parameters in the procedure declaration. If the number of expressions in the call differs from the number of declared parameters, then the call is ignored. Within the procedure, formal parameters are treated as if they were variables.

A PROCEDURE command must always have a corresponding ENDPROCEDURE command that marks the end of the procedure.

The number of formal parameters, plus the number of local variables, must not exceed the maximum parameters entry in the configuration file. The parameter size entry in the configuration file determines the maximum size of each formal parameter and local variable.

Example

procedure MyProc (item1, in item2, out item3, inout item 4)

Item1 and item2 are formal IN parameters, item3 is a formal OUT parameter, and item4 is a formal INOUT parameter.

procedure Summarize (DeptName, out AvgSalary) local (WorkVar)

WorkVar is a local variable (known only to procedure Summarize).

See Also

LOCALPROCEDURE

Defines and marks the start of a local procedure within an application program.

Syntax

LOCALPROCEDURE procname> ([IN|OUT|INOUT] parm)[LOCAL(var)]

Parameters

Comments

The body of a local procedure is a sequence of commands. A LOCALPROCEDURE must always end with a corresponding ENDPROCEDURE command.

Local procedure declarations must appear at the beginning of their application program document, before the main procedure or before the commands of a macro program. A local procedure cannot be nested within the body of another procedure or local procedure. Local procedures obey all the same call/return rules as standard procedures, and possess the same capabilities as a standard procedure.

A local procedure can call other procedures in the same application program document or in other program documents. However, a local procedure can be called only by other procedures defined in the same program document.

Example

localprocedure LocalProc1 ()

 transform LocalProc2 ()

endprocedure

%——————————————-

localprocedure LocalProc2 ()

 output “Hi from LocalProc2”

endprocedure

%——————————————-

procedure MainProc (Param1, Param2)

  LocalProc1 ()

  LocalProc2 ()

endprocedure

The main procedure calls two local procedures. The first local procedure transfers control to the second through a TRANSFORM command.

See Also

ENDPROCEDURE

PROCEDURE

Breaks the body of column-oriented reports into summary groups.

Syntax

COLUMN BREAK level [HEADING reportitem [:format:]]

[FOOTING reportitem [:format:]]

Parameters

Comments

The COLUMN BREAK command breaks the body of a column-oriented report into summary groupings.

Each time a BREAK command triggers a break at a specified level, the COLUMN BREAK for that level and all levels lower in the hierarchy are triggered.

Report items in the COLUMN BREAK heading can include individual values from the first member of the current group. Report items in the COLUMN BREAK footing can include individual values only from the last member of the current group. However, summary data computed over all members of the group can be displayed in the footing. Use aggregate functions.

If both the heading and footing clauses are omitted, a column break at the indicated level causes report formatting to recommence at the left-hand side of the page, beneath any previously formatted columns.

See Also

DETAIL LINE

ENDREPORT

REPORT FOOTING

REPORT FROM

REPORT HEADING

Enables conditional execution of commands.

Syntax

CASE

WHEN expression

commands1

[OTHERWISE

commands2]

ENDCASE

Parameters

Comments

A CASE command must always have a corresponding ENDCASE. Any number of WHEN clauses can appear between CASE and ENDCASE.

The WHEN phrases between CASE and ENDCASE are evaluated in order. Execution control transfers to the commands associated with the first WHEN clause whose expression is determined to be logically true. If none of the WHEN phrases contain an expression that evaluates to “true”, the commands associated with OTHERWISE (if used) are executed. Execution then resumes at the first command following ENDCASE.

If a WHEN expression includes fields from the current set, then the expression uses the values found in the current member of the current set.

If a BYE, RETURN, STOP, or TRANSFORM command exits a procedure in the middle of a CASE structure, the “open” CASE command is automatically closed. Also, if the end of the current procedure is reached before a necessary ENDCASE is encountered, the “open” CASE command is closed.

If the ENDCASE is missing, all subsequent commands in the current procedure are treated as part of the CASE structure.

Example

If the value for salary is neither less than 20,000, nor between 20,00 and 30,000, the first and second set of commands are skipped, and the third set of commands executed.

case

when salary < 20000

… first set of commands …

when Salary between 20000 and 20000

… second set of commands …

otherwise

… third set of commands …

endcase

The following program fragment illustrates how WHEN conditions in a CASE command can handle an application user’s choice of accelerator keys in an application. Depending on the key pressed by the application user, a particular procedure is executed.

form display input

case

when Event.EventName = “F3”

return

when Event.EventName = “F1”

AddNewRecord ()

when Event.EventName = “F2”

ChangeRecord ()

when Event.EventName = “F4”

DeleteRecord()

otherwise

GiveHelp ()

endcase

Finds records that match specified conditions, producing a result set.

Syntax

FIND [ num] [ setspec] [EVALUATE clause] [-> clause]

Parameters

Comments

Sets found using the FIND command are not stored permanently; they exist only for the current application session or until a DISPOSE SET command is executed.
If the -> clause is omitted, a result set is still produced. The unnamed result set can be referred to as CurrentSet for as long as it remains the current set.
Changes made to a record in an EntitySet or relationship are reflected in the result set, and vice versa.
$ SetCount and $ MemberCount are assigned a value equal to the number of members in the result set found by the FIND command.

Example

To find all employees whose last name is Smith, enter

find all Employees where LastName = “Smith” -> SmithSet

If you are working interactively at the command prompt, you could find it convenient to use the current unnamed result set when narrowing down a set of records. In the repeated FIND command, the second and third commands use the current set as their implicit setpsec:

> find Employees where Location = “Canada”

2019 selected

> find where LastName = “S”?

146 selected

> find where DeptNum = “D01”

7 selected

The name CurrentSet can also be used explicitly.
In application programs, you should explicitly name the result sets that you create with a FIND command. This technique is especially useful if you plan to compile a program that contains FIND commands:

procedure GetSet1 (a, b)

if a=b

find all Employees WorkIn Department -> KeepEmps

else

find all Employees WorkIn Department where LastName = a -> KeepEmps

endif

list all KeepEmps

endprocedure

You can use the FIND command to locate data, as shown in the following example:

find all Employees where LName = fEmployees.LastName

if $ setcount > 0

list all

else

  output “Nobody who works here is named: ” fEmployees.LastName

endif

You can also use FIND with forms as shown below:

find fItems where fItems.Qty > 0  % find values entered

See Also

$MemberCount

$SetCount

COMPUTE

INTERSECT

MINUS

UNION