The problem is, as long as we do support something, we want to support it consistently. */ /* Strings. With a true singleton, you don't have to instantiate the context class, but you would provide a "LoginContext.Current" property. So best programming practice is that whenever use the exclusive-lock also use the no-wait. What a PITA. We cannot compile an include file. 3) It would be very nice if the warning message itself were in the file and could be edited. You can use this pointer to: Position to and retrieve a record from a results list. Could a subterranean river or aquifer generate enough continuous momentum to power a waterwheel for the purpose of producing electricity? Is it possible to give different formats to the variables while defining using shared and new shared statements? The output to statement is your tool for redirecting the default stream to another destination. Q:- Is there a difference between a FIND and a FIND FIRST when the index is unique? How about using PUBLISH and SUBSCRIBE? 5. Ans:- Argument:- U can pass the argument at compile time. If going-way-back developers want to use them fine, but they should be moving to other technologies. 4. You can also get some basic help from the compiler (assuming you have a development license of some kind). What are the 4 ways to connect a Database? The update statement let you make changes to the record and progress upgrades the shared-lock to an Exclusive Lock. Mftitle.i - It contains all the globally defined variables in progress. Would My Planets Blue Sun Kill Earth-Life? How are engines numbered on Starship and Super Heavy? As, it is certain features that are prone to mis-use, (such as shared variables, CAN-DO and USE-INDEX) are, far too prominently featured in the documentation, and, in many cases, are held up as exemplars when. What are the different types of Blocks? Defines and identifies a variable that can be used by any procedure that names that variable using the DEFINE SHARED VARIABLE statement. Frames and dialog boxes contain field groups, and field groups contain field-level widgets or other frames. The called procedure must name the same variable in a DEFINE SHARED VARIABLE statement. Progress 4GL - Define variable month/year Ask Question Asked 7 years, 10 months ago Modified 7 years, 10 months ago Viewed 2k times 1 Here's the problem, i need to create a date range on the variable below. But, I'm not arguing that PSC shouldn't enhance their tool set, I'm just arguing that I don't want mandatory nagging in the compiler. Asking for help, clarification, or responding to other answers. Is there any way to store a session variable in OpenEdge SQL similar to how Oracle's RETURNING INTO clause works? This lock remains until the end of the transaction, which may be the end of Repeat Block. Of course, couldn't one simply put the despised keywords into the forget list and get error messages now? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. It can be created, stored and compiled separately from all other procedures as an operating system file. But how are you going to find this singleton object when: - there is no "static" specifier in the OO4GL (there is no "METHOD PUBLIC STATIC " nor a "STATIC CLASS " as far as I know). By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I don't think it's reasonable to expect a developer to read the entire handbook when they're looking for information on one language element. Specifying NO-UNDO for a variable is useful if you want to indicate an error condition as the value of the variable, perform an UNDO, and later take some action based on that error condition. What were the most popular text editors for MS-DOS in the 1980s? define variable s_date as character format "99/9999" no-undo. of a reverse reserved keyword kind of thing. Mfrchk.i to leave the loop when the report is running by using the endkey, Mfreset.i - when this is defined it will reset all the values stored after the iteration is over, Mfnp.i to display the datas from the table for the corresponding when you scroll using arrow keys. Not only does that provide the programmer new to this area with guidance in the right usage pattern, but it will help to educate him or her on how he or she might rework older code. Yes, I think the original question is asking about passing parameters into a start-up command line. They don't want to make people feel like they have to change what they are doing in order to move to the latest release. github.com/abevoelker/do/tree/add-openedge-adapter/do_openedge, How a top-ranked engineering school reimagined CS curriculum (Ep. Define shared variable variable name during the definition of the variable in other sub programs. Progress uses that buffer to store one record at a time from the table as the records are needed during the procedure. Searches the directories and libraries defined in the PROPATH environment variable for a file. Progress 4GL is an application development language which has a highly readable syntax employing a default behavior while performing the work of multiple 3GL statements. For a better experience, please enable JavaScript in your browser before proceeding. Individual positions i the array is accessed using "standard" c-style brackets. What should I follow, if two altimeters show different altitudes? Reactions:trmrahim One of the, places I see this a lot, and it really drives me nuts, is in, Actuate Basic, which is OO. But let's foster and maintain a professional and friendly tone. I need a column value set by a trigger to be available after running an INSERT without having to do another SELECT. Learn progress-4gl - Progress ABL is statically typed. For first can use multiple indexes and Find cab use only one index. People are just lazy about learning how. I would submit that whenever old language elements are described, something needs to be included saying they're old / historical and references made to other techniques which provide better / safer ways of accomplishing the same thing. For first can use multiple indexes and Find cab use only one index. We have ProLint for telling us things like the use of deprecated features. 3. "Don't want" is not a requirement I take very. Brooks proved that there are none of those to be had 20 years ago. OpenEdge SQL: 'variable' feature similar to Oracle PL/SQL "RETURNING INTO"? Record Buffer - A temporary storage area in data memory for a record, field or variable. The STREAM-IO option allows you to redirect the output of a report-generating. Yes, and one can make a good case that static variables are also evil and are bad OO. If you need more than one record at a time from a table, you can use the DEFINE BUFFER statement to define additional buffers for that table. How much RAM does my database and processes use. How to accept input parameters in Progress procedure The "Evil-ness" of something isn't necessarily about their existence, but how they're used or are abused in order to (wrongly) accomplish a particular goal. That states that no undo handling is wanted for this specific variable in case of a transactional roll-back. Q:- Progress supports how many types of variable? Interesting to read that ABL triggers run in the context of the client, while SQL triggers run on the server (source: OpenEdge 11 SQL Development p151). For is a progress block and find is a progress statement. Define new shared variable variable name during the first time the variable is defined in the main program. I'm skimming John Sadd's OE 4GL handlebook "expert series" (http://www.psdn.com/library/entry.jspa?categoryID=239&externalID=474) and came across this reference on page 14-24: The traditional Progress programming technique of using SHARED variables. Continue to blog.Data Engineering ServicesAI & ML SolutionsData Analytics ServicesData Modernization Services. What is deadlock? Returns a 0 if the expression is not in the list. So it's not like PSC hasn't marked things as deprecated before. Why refined oil is cheaper than cold press oil? This should always be the default unless transactional control over this variable is a requirement. Shared variables are a technology fraught with dangers and has long since been obsoleted by other, better technologies in the ABL. However, in my case the only communication I have with OpenEdge is through the JDBC driver to the SQL-92 engine. C# example: Any code that uses "person.GetName()" will get a compiler warning "Use Name instead". When you view a frame, that frame and all widgets contained within it are displayed except those widgets whose HIDDEN attributes are set to TRUE. Yes, there are. AS primitive-type-name That's not true, since you have instantiated and deleted this context object all over your code! Such as using shared variables / temp-tables as an example of procedural programming in the new OO intro docs translation here. Is it necessary to use a READKEY Statement in the EDITING Phrase? 1. BTW -- I do agree that the documentation should be done differently. DEFINE VARIABLE chand AS CHARACTER NO-UNDO. If there existed a SQL function that would return a special session ID that corresponded to the client's transient connection to the SQL engine, it would be possible to have the client and trigger/stored procedure communicate using a pre-determined table as a request queue (by using the session ID as a key). What is the difference between Prompt-For statement and Set Statement? After the procedure execution completes the values are deleted. And .Net has a nifty feature: the ObsoleteAttribute. Normalization is a design technique that is widely used as a guide in designing relational databases. Will look for the string "shared var" in any case in all *.p files. Without nag messages everyone gets to profess surprise that such and such a feature is deprecated when we have all known forever that it was a bad thing. Progress Documentation . //A case sensitive ('a' <> 'A') variable. Perhaps there should even be a section in the docs on "practices to be avoided", BTW -- I do agree that the documentation should be, done differently. . This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. Purchase orders contain a single delivery date for each line item. What are types of locks? See Trademarks for appropriate markings. Ans:- Transaction is a set code which completely done the program or completely undone the program. ', referring to the nuclear power plant in Ignalina, mean? Unique Index - An indexed field where every index key must be different. What is an Include file? 1. Get monthly updates about new articles, cheatsheets, and tricks. What is the definition of shared variable? Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Delphi connection to OpenEdge Progress-4GL Database, progress 4gl OpenEdge abl delete file from directory, Reflection in OpenEdge ABL / Progress 4GL, OpenEdge - Progress ABL: How to open a web browser inside a dialog window, OpenEdge Progress 4GL Query returns (MISSING) after % sign, Progress 4GL - How to create infinite scroll browse, PROCESS EVENTS not working inside the OUTPUT TO - PROGRESS 4GL. DEFINE VARIABLE a AS CHARACTER EXTENT 5 NO-UNDO. Progress Documentation It allows you to modularize your code and reduce the number of external files in an application. So maybe we should be documenting "worst practices". Multi-table deadlocks can be avoided by locking the tables in same order in all applications, thus preventing a deadlock condition. Defines or forward declares a user-defined function. Word Index - An index that contains all the words from a text field or array of text fields so you can search for records containing specific words or phrases. What is the difference between ENABLE and VIEW Statement? Which was the first Sci-Fi story to predict obnoxious "robo calls"? Identify blue/translucent jelly-like animal on beach. All relevant tables associated with the online maintenance are updated correctly. Other languages provide equivalent constructs with the "static" keyword for session wide, global variables and "ThreadLocal" or "thread static" variables for thread-scoped variables. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. an SP or singleton object designed to provide such values and, simply retrieve it as necessary. Another factor is that a set of best practice, standards is not well established and universally. If some nags were to (finally) be inserted in OE10 we might begin to see some general recognition that, oh say shared variables, are a bad idea by the time version 13 rolls out. Character, Date, Decimal, Integer, RowID, RecID, Raw, Logical, Handle, MEMPTR. For a better experience, please enable JavaScript in your browser before proceeding. What is a trigger and what are the different types of triggers? In above example if u doesnt mention the NO-WAIT clause and mean while if user1 has gone for some other work/tea, then user2 will hit the database every time to update the record, means progress will not move the next line of code until it will not get the release of exclusive-lock. Weak Scoped Reference - if you have weak scope referenced buffer, you can reference that same buffer outside the weak scoped block. Did I not indicate that it is very possible to write bad OO code? Identifies the process that follows each keystroke during a PROMPT-FOR, SET, or UPDATE statement. UNFORMATTED - Tells Progress to display each expression in the same format produced by the EXPORT statement, but without quotes. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Yes, it is a workaround, but it is a workaround that works! Session triggers are defined as part of a particular application and are only in effect for that particular application. PROGRESS supports 2 types of database triggers: Always execute when a specified event occurs, regardless of what application initiates the event. We all understand why PSC has chosen to support historical syntax in later versions. After half a year, I began understand the intricacies of working with this server and procedures written in ABL. The DESCENDING option sorts the records in descending order as opposed to the default ascending order. Typically each block begins with the header statement and ends with the END statement. A trigger is a block of 4GL code that executes whenever a specific event occurs. DEFINE VARIABLE whand AS HANDLE NO-UNDO. To be sure, there are lots of us out here with legacy apps filled with shared variables. This has long been one of PSC's, great strengths and the failure of people to, keep moving forward has certainly turned into. But obsolete if not dangerous techniques shouldn't be listed as examples of how to work with the product's current technology when there are better and safer ways to accomplish the same thing. Please give a brief about no-undo and undo option. User interface trigger - A block of 4GL code associated with an event-object pair. I wrote a Progress 4GL procedure which is actually a script saved in OS (not in database). Connect and share knowledge within a single location that is structured and easy to search. What will you write in the CIM program to specify F1, F4 key, Enter and for Default option? I want to set SESSION:TEMP-DIRECTORY without hard-cording the value in pf file. Shared lock is the default lock used in progress. If no locks are specified then it will be specified as shared lock. will include (any day now, we promise, Thomas). Are compiled separately from the procedure that initiates their execution, they do not have access to the procedures frame, widgets and variables. 3. And, another factor I think is that PSC seems to be very conscious of the fact that there are a lot of people who are not out at the leading edge, especially if they are sitting on million line bodies of existing code. If it was easier for legacy developers to move things forward, maybe they would. Normalization theory is based on the concepts of normal forms. OUTPUT PARAMETER - Defines a parameter that returns a value to one of the following destinations: If the calling procedure runs the current (called) procedure synchronously, the value is returned to the corresponding OUTPUT parameter of the RUN statement in the calling procedure. It is important to continue to support existing code, at least for a significant period. Non-Persistent Procedure maintains and creates its context only it returns from execution. It may not display this or other websites correctly. //An character array with length = 5, DEFINE VARIABLE j AS INTEGER EXTENT NO-UNDO. You can always use operating system utilities like grep. DEFINE VARIABLE i AS INT64 INITIAL -200 NO-UNDO. I can understand existing "shared" support remaining in the language, but adding support for shared "stuff" in new technology like PDS??? /* These variables are declared with `NO-UNDO`. provide an immediate value for the PK themselves, provide a sequence that corresponds to the table that they are updating. What will be the lock when we read the record and update the record? Data integrity means that Progress stores completed data and does not store incomplete data in the. DEFINE VARIABLE statement - Progress.com Persistent Procedure creates it context when it executes and then maintains it context after it runs until the end of the progress session, or until it explicitly deleted. Does internal procedure create .r file during execution? Would My Planets Blue Sun Kill Earth-Life? We use the temp table in client server architecture. In some cases, they might even be a, necessary evil, but I advocate making sure that everyone is clear, that they are still evil because otherwise people just start using, them freely, the way they have with shared variables. Q:- What is difference between STREAM , OUTPUT TO, and OUTPUT TO VALUE? For is a progress block and find is a progress statement. Boy, you step out of the room for a minute (well, to, Greece and back and various other places) and all. What is Wario dropping at the end of Super Mario Land 2 and why? Explain the data moves between the calling procedure and the called procedure depending on the Parameter type. (Could be thought somehow as the 'reverse' to the existing keyword forget list). //A variable with a label. Set - is the combination of Prompt-For + Assign. It is the most basic procedure, which can contain a single 4GL statement, many statements, or it can be an empty file. SYNTAX:- NUM-ENTRIES ( list [ , character ] ). Unexpected uint64 behaviour 0xFFFF'FFFF'FFFF'FFFF - 1 = 0? If you haven't got a Progress session then you can run it from the command prompt with the statement rrojo7229 gave. What are the different types of data types available in progress? Shared Variable - Defines a variable that was created by another procedure that used the DEFINE NEW SHARED VARIABLE or DEFINE NEW GLOBAL SHARED VARIABLE statement. Ans:- Progress provides you with one buffer for each table that you use in a procedure. Shared variables have uses too. At data movement time, Progress overlays any existing data in the receiving temp table unless you define the receiving temp table with the APPEND option. rev2023.5.1.43405. Can-do function :- Checks a string value against two types of comma-separated lists: An ID list of one or more user permission strings that indicate what users have access to the current procedure. 2. find returns the value as per where clause and can-find returns the logical value. This behavior supports recursive procedures and bill-of-materials applications. That does not make it a virtue to guide people toward usage which we now recognize as undesireable. All validation used in these programs during normal data entry is available during a CIM load. put even more strongly, it's because the book was, trying to strike a balance between material for those, who may be maintaining older applications and those, There are a number of places in the book. So I would say that shared variables were discussed in the book "for historical reference", and if their disadvantages weren't sufficiently emphasized, well, shoot me, but we are doing our best to move the community forward while at least acknowledging that newer better programming mechanisms co-exist (happily, for the most part) with older code that remains successful for what it does and will continue to do so. How will you avoid that? 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. Screen Buffer:- to display the data on screen from record buffer. SYNTAX:- R-INDEX ( source , target [ , starting ] ). It would cause people, with some code bases to avoid upgrading and it would, break a lot of automated build processes. The, compiler should be silent unless there is something, fatal or a good reason to expect that the code will, not perform as intended (like moving colon. Which was the first Sci-Fi story to predict obnoxious "robo calls"? You will have to look into converting it to fit your form. Progress ABL is a strongly typed, late-bound, English-like programming language with growing support for object orientation. For Starship, using B9 and later, how will separation work if the Hydrualic Power Units are no longer needed for the TVC System? I know I didn't read the entire book, and I have no intention of doing so since I was only looking for specific material I need to figure out. Untill then the data can be undone using undo statement. Why does Acts not mention the deaths of Peter and Paul? It is a block of code defined within an external procedure that you can execute by name within the context of the containing external procedures. Progress has the ability to use and understand SQL, but the overwhelming majority of application development is done using the native 4GL, which is held in high regard because it gives programmers the power that SQL has historically lacked, and that products like Oracle's PL/SQL and Power builders Transact/SQL attempt to provide with varying degrees of success. For First fetch the data from record list and Find first fetch the data from record buffer. To learn more, see our tips on writing great answers. There is a start_date column in my db (format "99/99/9999"(dd/mm/yyyy)) the date when a customer sales order was entered. Can we use it in the where clause? The third line will procude the following error: You can use the INITIAL option on the DEFINE VARIABLE statement to set initial values. But seriously, OO is an interesting idea that makes some problem domains simpler. Maintenance - Add / Modify / Delete database record, Inquiry - Simple formatted extract without batch id option, Report - Detail formatted extract with batch id option with. As it stands there is no incentive for anyone to change bad habits -- and there are plenty of bad habits that need changing. Being able to use 'deprecated' langauge elements is one thing. . I can go with that a few releases, but sooner or later the docs need to be. is there such a thing as "right to be heard"? Without wanting to intensify the war, shared variables are in fact a very powerful things and there are some very specific cases where shared variables can have very positive side affects, like improved performance. Nor is it a silver bullet. There are a number of places in the book where I try to describe outdated features, while leaving it to others in the company to make formal definitions of what is "deprecated" and what that really means. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.