IBM i (AS400) fans only ' Realtime exchange rate for any pair of physical and digital currency reading JSON data from a webservice with RPG, SQL and HTTPGETCLOB function

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Realtime exchange rate for any pair of digital or physical currency using HTTP GET and JSON_TABLE reading with SQL HTTPGETCLOB.


This CLP is intended to test the FREX00.SQLRPGLE utility.


 
FREX00CL.CLP - convert exchange rates between two currencies

PGM        PARM((&CURRENCY_1) +                
                (&CURRENCYN2) +                
                (&CURRENCY_3) +                
                (&CURRENCYN4) +                
                (&EXCHANGER5) +                
                (&EXCHANGED6) +                
                (&TIME_ZONE7) +                
                (&BID_PRICE8) +                
                (&ASK_PRICE9) +                
                (&ERROR_CODA))                 
                                               
DCL        VAR(&CURRENCY_1) TYPE(*CHAR) LEN(03)
DCL        VAR(&CURRENCYN2) TYPE(*CHAR) LEN(50)
DCL        VAR(&CURRENCY_3) TYPE(*CHAR) LEN(03)
DCL        VAR(&CURRENCYN4) TYPE(*CHAR) LEN(50)
DCL        VAR(&EXCHANGER5) TYPE(*CHAR) LEN(15)
DCL        VAR(&EXCHANGED6) TYPE(*CHAR) LEN(20)
DCL        VAR(&TIME_ZONE7) TYPE(*CHAR) LEN(03)
DCL        VAR(&BID_PRICE8) TYPE(*CHAR) LEN(25)
DCL        VAR(&ASK_PRICE9) TYPE(*CHAR) LEN(25)                 
DCL        VAR(&ERROR_CODA) TYPE(*CHAR) LEN(01)                 
                                                                
CALL       PGM(FREX00)        +                                 
           PARM((&CURRENCY_1) +                                 
                (&CURRENCYN2) +                                 
                (&CURRENCY_3) +                                 
                (&CURRENCYN4) +                                 
                (&EXCHANGER5) +                                 
                (&EXCHANGED6) +                                 
                (&TIME_ZONE7) +                                 
                (&BID_PRICE8) +                                 
                (&ASK_PRICE9) +                                 
                (&ERROR_CODA) )                                 
                                                                
SNDUSRMSG  MSG('1. From_Currency Code:' *CAT %TRIM(&CURRENCY_1))
SNDUSRMSG  MSG('2. From_Currency Name:' *CAT %TRIM(&CURRENCYN2))
SNDUSRMSG  MSG('3. To_Currency Code  :' *CAT %TRIM(&CURRENCY_3))
SNDUSRMSG  MSG('4. To_Currency Name  :' *CAT %TRIM(&CURRENCYN4))
SNDUSRMSG  MSG('5. Exchange Rate     :' *CAT %TRIM(&EXCHANGER5))
SNDUSRMSG  MSG('6. Last Refreshed    :' *CAT %TRIM(&EXCHANGED6))
SNDUSRMSG  MSG('7. Time Zone         :' *CAT %TRIM(&TIME_ZONE7))
SNDUSRMSG  MSG('8. Bid Price         :' *CAT %TRIM(&BID_PRICE8))
SNDUSRMSG  MSG('9. Ask Price         :' *CAT %TRIM(&ASK_PRICE9))
SNDUSRMSG  MSG('                     :' *CAT %TRIM(&ERROR_CODA))
                                                                
ENDPGM                                                          


FREX00      SQLRPGLE    convert exchange rates between two currencies

**free
  // **********************************************************************************************
  //                                                                                              *
  // Realtime Currency Exchange Rate Reader                                                       *
  //                                                                                              *
  // How to get json data from a webservice with RPG, SQL and HTTPGETCLOB function                *
  //                                                                                              *
  // **********************************************************************************************
  //                                                                                              *
  // I have been using AlphaVantage's API service for financial market data and I am extremely    *
  // impressed with the quality of their data and the ease of use of their platform.              *
  // Their API is well-documented and easy to integrate into my projects, and I appreciate the    *
  // fact that they offer a free tier of service for small-scale projects.                        *
  // The data provided by AlphaVantage is accurate and up-to-date, and I have found it to be      *
  // an invaluable resource for my test.                                                          *
  // Their customer support team is also very responsive and helpful in answering any questions   *
  // I have had.                                                                                  *
  // Overall, I highly recommend AlphaVantage to anyone who needs reliable and high-quality       *
  // financial market data.                                                                       *
  // Thank you, AlphaVantage, for providing such a great service!                                 *
  //                                                                                              *
  // I have successfully used AlphaVantage's API "Realtime Currency Exchange Rate" in this        *
  // RPGfree with SQL embedded sample program                                                     *
  //                                                                                              *
  // Type to test this program:                                                                   *
  // CALL PGM(FREX00CL) PARM(('GBP') (' ') ('EUR') (' ') (' ') (' ') (' ') (' ') (' ') (' '))     *
  // **********************************************************************************************
  //                                                                                              *
  // Another interesting AlphaVantage API is the 'Global Quote'. I plan to publish an example     *
  // that uses this API shortly.                                                                  *
  // https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=IBM&apikey=demo               *
  //                                                                                              *
  // **********************************************************************************************
  ctl-opt option(*nodebugio:*srcstmt:*nounref) dftactgrp(*no)
  ALWNULL(*USRCTL) ;

  dcl-c cURL1 'https://www.alphavantage.co/';
  dcl-c CURL2 'query?function=CURRENCY_EXCHANGE_RATE';
  dcl-c cURL3 '&from_currency=';
  // EUR
  dcl-c cURL4 '&to_currency=';
  // JPY
  dcl-c cURL5 '&apikey=EGFIVJ80H10MTIP6';

  dcl-s URL char(123);

  dcl-ds Pgm psds qualified ;
    User             char(10) pos(358); // 358 367 Current user
  end-ds ;

  dcl-pi FREX00;
    CURRENCY_1 char(03);
    CURRENCYN2 char(50);
    CURRENCY_3 char(03);
    CURRENCYN4 char(50);
    EXCHANGER5 char(15);
    EXCHANGED6 char(20);
    TIME_ZONE7 char(03);
    BID_PRICE8 char(25);
    ASK_PRICE9 char(25);
    ERROR_CODA char(01);
  end-pi;

  exec sql set option Commit = *None;
  exec sql set option SRTSEQ = *LANGIDSHR;

  // **************************************************
  // start working
  // **************************************************
  ERROR_CODA = 'E'; // Error
  URL = cURL1 + cURL2 + cURL3 + %trim(CURRENCY_1) + cURL4 +
        %trim(CURRENCY_3) + cURL5;
  exec sql select * into :CURRENCY_1, :CURRENCYN2, :CURRENCY_3, :CURRENCYN4,
                         :EXCHANGER5, :EXCHANGED6, :TIME_ZONE7, :BID_PRICE8,
                         :ASK_PRICE9
    from JSON_TABLE(SYSTOOLS.HTTPGETCLOB(:URL, null),
             'lax $."Realtime Currency Exchange Rate"' COLUMNS (
              FromCurrencyCode varchar(03) path '$."1. From_Currency Code"',
              FromCurrencyName varchar(50) path '$."2. From_Currency Name"',
              ToCurrencyCode   varchar(03) path '$."3. To_Currency Code"',
              ToCurrencyName   varchar(50) path '$."4. To_Currency Name"',
              ExchangeRate     varchar(15) path '$."5. Exchange Rate"',
              LastRefreshed    varchar(20) path '$."6. Last Refreshed"',
              TimeZonex        varchar(03) path '$."7. Time Zone"',
              BidPrice         varchar(25) path '$."8. Bid Price"',
              AskPrice         varchar(25) path '$."9. Ask Price"'
            ) empty on error
    );
    if sqlcode = 0;
      ERROR_CODA = ' ';
    endif;
  *inlr = *on;

Type the following to test the program:
CALL PGM(FREX00CL) PARM(('GBP') (' ') ('EUR') (' ') (' ') (' ') (' ') (' ') (' ') (' '))

I appreciate all the comments made on this blog.


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