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URL: https://www.cdata.com/kb/tech/cvent-odbc-foxpro.rst

⇱ Work with Cvent Data in FoxPro

Work with Cvent Data in FoxPro

👁 Jerod Johnson
Jerod Johnson
Director, Technology Evangelism
Load Cvent data into a FoxPro database. This article includes full code and a walk-through of the process.

The CData ODBC driver for Cvent enables you to access Cvent data using the ODBC standard. You can use the CData ODBC Driver for Cvent to integrate Cvent data into your FoxPro project. The procedure below provides a walk-through of the included code sample, which saves Cvent data into tables in a FoxPro database.

Connect to Cvent as an ODBC Data Source

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

NOTE: Set the 'Map To WVarchar' connection property to FALSE (FoxPro uses the ODBC W API and returns the WCHAR for the value type).

Before you can authenticate to Cvent, you must create a workspace and an OAuth application.

Creating a Workspace

To create a workspace:

  1. Sign into Cvent and navigate to App Switcher (the blue button in the upper right corner of the page) >> Admin.
  2. In the Admin menu, navigate to Integrations >> REST API.
  3. A new tab launches for Developer Management. Click on Manage API Access in the new tab.
  4. Create a Workspace and name it. Select the scopes you would like your developers to have access to. Scopes control what data domains the developer can access.
    • Choose All to allow developers to choose any scope, and any future scopes added to the REST API.
    • Choose Custom to limit the scopes developers can choose for their OAuth apps to selected scopes. To access all tables exposed by the driver, you need to set the following scopes:
      event/attendees:readevent/attendees:writeevent/contacts:read
      event/contacts:writeevent/custom-fields:readevent/custom-fields:write
      event/events:readevent/events:writeevent/sessions:delete
      event/sessions:readevent/sessions:writeevent/speakers:delete
      event/speakers:readevent/speakers:writebudget/budget-items:read
      budget/budget-items:writeexhibitor/exhibitors:readexhibitor/exhibitors:write
      survey/surveys:readsurvey/surveys:write

Creating an OAuth Application

After you have set up a Workspace and invited them, developers can sign up and create a custom OAuth app. See the Creating a Custom OAuth Application section in the Help documentation for more information.

Connecting to Cvent

After creating an OAuth application, set the following connection properties to connect to Cvent:

  • InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
  • OAuthClientId: The Client ID associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.
  • OAuthClientSecret: The Client secret associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.

Connect and Transfer

To get started, add the code sample to a new project. You can execute the following command to save all tables without displaying them:

DO C:\Temp\sqldump.prg WITH "CData Cvent Source", "TESTDB", .f.

Below is the process that the program follows:

  1. Create a new FoxPro database.

  2. Open a connection to Cvent data with the line below:

    m.hSQLconnection = SQLCONNECT(m.cODBCDSN)

  3. If the connection was successful, you can now retrieve the list of tables using the SQLTABLES function. The code below saves the list of tables in sys_tables.dbf:

    WAIT WINDOW "Fetching tables for data source '" + m.cODBCDSN + "'..." NOWAIT NOCLEAR
m.nSQLTABLES = SQLTABLES(m.hSQLconnection)

IF lUseDistinctConnections
 WAIT WINDOW "Closing ODBC Connection for data source '" + m.cODBCDSN + "'..." NOWAIT NOCLEAR
 SQLDISCONNECT(m.hSQLconnection)
 m.hSQLconnection = 0 * SQLCONNECT needs to be called again
ENDIF

IF m.nSQLTABLES > 0
 * create local table containing list of tables in db
 COPY TO (m.cImportData + "sys_tables")
 USE

 * convert each table to DBF
 USE (m.cImportData + "sys_tables")
 ALTER TABLE DBF("sys_tables") ;
 ADD COLUMN records i ;
 ADD COLUMN dbfname m
  4. Scan over each table, saving it to a DBF file. The function ODBCtoDBF stores the table in a DBF file and then opens a grid if the lBrowse parameter is set to true: 
    FUNCTION ODBCtoDBF (cTableName as String, cTableType as String, lBrowse as Logical, lhSQLConnection as Integer)

 WAIT WINDOW ;
 "Converting " + m.cTableType + ' "' + m.cTableName + '" to DBF...' ;
 NOWAIT NOCLEAR

 ACTIVATE SCREEN

 * strip characters incompatible with FoxPro out of the name of the DBF file
 m.cTableAlias		= ""
 m.nTableNameLen		= LEN(m.cTableName)
 m.nTableNameStart	= 1
 
 FOR m.nTableNameStart = 1 TO m.nTableNameLen
 m.cCharacter = SUBSTR(m.cTableName, m.nTableNameStart, 1)	
 IF !ISALPHA(m.cCharacter) .and. (m.nTableNameStart = 1 .or. !ISDIGIT(m.cCharacter))
 m.cTableAlias = m.cTableAlias + "_"
 ELSE
 m.cTableAlias = m.cTableAlias + m.cCharacter
 ENDIF
 ENDFOR

 m.cFromTable = m.cTableName
 m.cTempViewAlias	= m.cTableType + "_" + m.cTableAlias

 LOCAL loException as Exception
 LOCAL lnResultSets
 
 TRY
 * run query
 m.lnResultSets = SQLEXEC(m.lhSQLConnection, ;
 "SELECT * FROM " + m.cFromTable, ;
 m.cTempViewAlias, ;
 aSQLResult)
	 
 IF m.lnResultSets#1
 SET STEP ON
 ENDIF
	
 ACTIVATE SCREEN

 CATCH TO m.loException
 ACTIVATE SCREEN
 ? "Error opening " + m.cTempViewAlias + ":"
 ? m.loException.Message
 ? m.loException.Details
 ENDTRY

 IF !USED(m.cTempViewAlias)
 RETURN
 ENDIF

 * copy records from view cursor to disk
 SELECT * FROM (m.cTempViewAlias) ;
 INTO TABLE (m.cImportData + m.cTableAlias)

 IF USED(m.cTableAlias)

 ACTIVATE SCREEN

 FLUSH	&& flush the buffer to write the data to disk

 IF m.lBrowse
 * pop the table up on screen
 SELECT (m.cTableAlias)
 BROWSE NORMAL NOMODIFY NOWAIT
 ACTIVATE SCREEN
 ELSE
 * close on-disk table for now
 USE IN (m.cTableAlias)
 ACTIVATE SCREEN
 ENDIF
 ENDIF

 IF USED(m.cTempViewAlias)
 USE IN &cTempViewAlias && close SQL view
 ACTIVATE SCREEN
 ENDIF

 WAIT CLEAR

ENDFUNC
  5. You can now save tables of Cvent data as DBF files.

Below is the full code, in FoxPro 9 syntax: 

PARAMETERS cODBCDSN, cDatabaseName, lBrowseAfterConvert

*	cODBCDSN				The ODBC data source name, used for the name of the folder where the DBF tables are stored.
*	cDatabaseName			The name of the FoxPro database to use. This database is created if it does not exist. The default is DATABASE_NAME.
*								
*	lBrowseAfterConvert		If ".t." display each table with the BROWSE command after importing it. If ".f." close each table before moving on to the next one.

#define		ODBC_DATASOURCE		"DataSourceName"
#define		DATABASE_NAME		"odbcdata"

m.m_tpath = ".\" && root directory for data

ON ERROR
SET SAFETY OFF

IF VARTYPE(m.cODBCDSN)#"C" .or. EMPTY(m.cODBCDSN)
 m.cODBCDSN = ODBC_DATASOURCE
ENDIF
IF VARTYPE(m.cDatabaseName)#"C" .or. EMPTY(m.cDatabaseName)
 m.cDatabaseName = DATABASE_NAME
ENDIF

m.cImportData = m.cODBCDSN + "\"

CLOSE TABLES ALL
CLOSE DATABASES ALL

IF !DIRECTORY(m.cImportData)
	MKDIR (m.cImportData)
ENDIF

CREATE DATABASE (m.cDatabaseName)
CREATE CONNECTION (m.cDatabaseName) DATASOURCE (m.cODBCDSN) DATABASE (m.cDatabaseName)

WAIT WINDOW "Opening ODBC Connection for data source '" + m.cODBCDSN + "'..." NOWAIT NOCLEAR
m.hSQLconnection = SQLCONNECT(m.cODBCDSN)

IF m.hSQLconnection > 0
 * Connection successful; get list of tables
 WAIT WINDOW "Fetching tables for data source '" + m.cODBCDSN + "'..." NOWAIT NOCLEAR
 m.nSQLTABLES = SQLTABLES(m.hSQLconnection)

 IF m.nSQLTABLES > 0
 * Create local table containing list of tables in db
 COPY TO (m.cImportData + "sys_tables")
 USE

 * Convert each table to DBF
 USE (m.cImportData + "sys_tables")
 ALTER TABLE DBF("sys_tables") ;
 ADD COLUMN records	i ;
 ADD COLUMN dbfname	m

 SCAN	
 m.cCurrentTable	= TRIM(sys_tables.table_name)
 m.cCurrentTableType	= TRIM(sys_tables.table_type) && Valid values are "SYSTEMTABLE", "TABLE", and "VIEW".
 IF m.cCurrentTableType = "TABLE" or m.cCurrentTableType = "VIEW"

 ODBCtoDBF(m.cCurrentTable, m.cCurrentTableType, m.lBrowseAfterConvert, m.hSQLConnection)
 ELSE
 ACTIVATE SCREEN
 ? "ERROR:", m.cCurrentTable, "Couldn't open ODBC connection."
 =MESSAGEBOX("couldn't open data source " + m.cODBCDSN + " for table " + m.cCurrentTable + ".")
 ENDIF

 ENDSCAN
 BROWSE NORMAL NOWAIT

 ELSE
 =MESSAGEBOX("No tables found in data source " + m.cODBCDSN + ".")
 SET STEP ON
 ENDIF
 
 SQLDISCONNECT(m.hSQLconnection)
 
ELSE
 =MESSAGEBOX("Could not open data source " + m.cODBCDSN + ".")
 SET STEP ON
ENDIF

FUNCTION ODBCtoDBF (cTableName as String, cTableType as String, lBrowse as Logical, lhSQLConnection as Integer)

 WAIT WINDOW ;
 "Converting " + m.cTableType + ' "' + m.cTableName + '" to DBF...' ;
 NOWAIT NOCLEAR

 ACTIVATE SCREEN

 * Strip characters incompatible with FoxPro out of the name of the DBF file
 m.cTableAlias		= ""
 m.nTableNameLen		= LEN(m.cTableName)
 m.nTableNameStart	= 1
 
 FOR m.nTableNameStart = 1 TO m.nTableNameLen
 m.cCharacter = SUBSTR(m.cTableName, m.nTableNameStart, 1)	
 IF !ISALPHA(m.cCharacter) .and. (m.nTableNameStart = 1 .or. !ISDIGIT(m.cCharacter))
 m.cTableAlias = m.cTableAlias + "_"
 ELSE
 m.cTableAlias = m.cTableAlias + m.cCharacter
 ENDIF
 ENDFOR

 m.cFromTable = m.cTableName
 m.cTempViewAlias	= m.cTableType + "_" + m.cTableAlias

 LOCAL loException as Exception
 LOCAL lnResultSets
 
 TRY
 * Run query
 m.lnResultSets = SQLEXEC(m.lhSQLConnection, ;
 "SELECT * FROM " + m.cFromTable, ;
 m.cTempViewAlias, ;
 aSQLResult)
	 
 IF m.lnResultSets#1
 SET STEP ON
 ENDIF
	
 ACTIVATE SCREEN

 CATCH TO m.loException
 ACTIVATE SCREEN
 ? "Error opening " + m.cTempViewAlias + ":"
 ? m.loException.Message
 ? m.loException.Details
 ENDTRY

 IF !USED(m.cTempViewAlias)
 RETURN
 ENDIF

 * Copy records from view cursor to disk
 SELECT * FROM (m.cTempViewAlias) ;
 INTO TABLE (m.cImportData + m.cTableAlias)

 IF USED(m.cTableAlias)

 ACTIVATE SCREEN

 FLUSH	&& Flush the buffer to write the data to disk

 IF m.lBrowse
 * Display the table on screen
 SELECT (m.cTableAlias)
 BROWSE NORMAL NOMODIFY NOWAIT
 ACTIVATE SCREEN
 ELSE
 * Close on-disk table
 USE IN (m.cTableAlias)
 ACTIVATE SCREEN
 ENDIF
 ENDIF

 IF USED(m.cTempViewAlias)
 USE IN &cTempViewAlias && Close SQL view
 ACTIVATE SCREEN
 ENDIF

 WAIT CLEAR

ENDFUNC

Ready to get started?

Download a free trial of the Cvent ODBC Driver to get started:

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Cvent ODBC Driver

The Cvent ODBC Driver is a powerful tool that allows you to connect with live data from Cvent, directly from any applications that support ODBC connectivity.

Access Cvent data like you would a database - read, write, and update Cvent 0, etc. through a standard ODBC Driver interface.