Work with IBM Cloud Object Storage Data in FoxPro


Load IBM Cloud Object Storage data into a FoxPro database. This article includes full code and a walk-through of the process.

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

Connect to IBM Cloud Object Storage 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).

Register a New Instance of Cloud Object Storage

If you do not already have Cloud Object Storage in your IBM Cloud account, follow the procedure below to install an instance of SQL Query in your account:

  1. Log in to your IBM Cloud account.
  2. Navigate to the page, choose a name for your instance and click Create. You will be redirected to the instance of Cloud Object Storage you just created.

Connecting using OAuth Authentication

There are certain connection properties you need to set before you can connect. You can obtain these as follows:

API Key

To connect with IBM Cloud Object Storage, you need an API Key. You can obtain this as follows:

  1. Log in to your IBM Cloud account.
  2. Navigate to the Platform API Keys page.
  3. On the middle-right corner click "Create an IBM Cloud API Key" to create a new API Key.
  4. In the pop-up window, specify the API Key name and click "Create". Note the API Key as you can never access it again from the dashboard.

Cloud Object Storage CRN

If you have multiple accounts, specify the CloudObjectStorageCRN explicitly. To find the appropriate value, you can:

  • Query the Services view. This will list your IBM Cloud Object Storage instances along with the CRN for each.
  • Locate the CRN directly in IBM Cloud. To do so, navigate to your IBM Cloud Dashboard. In the Resource List, Under Storage, select your Cloud Object Storage resource to get its CRN.

Connecting to Data

You can now set the following to connect to data:

  • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
  • ApiKey: Set this to your API key which was noted during setup.
  • CloudObjectStorageCRN (Optional): Set this to the cloud object storage CRN you want to work with. While the connector attempts to retrieve this automatically, specifying this explicitly is recommended if you have more than Cloud Object Storage account.

When you connect, the connector completes the OAuth process.

  1. Extracts the access token and authenticates requests.
  2. Saves OAuth values in OAuthSettingsLocation to be persisted across connections.

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 IBMCloudObjectStorage Source", "TESTDB", .f.

Below is the process that the program follows:

  1. Create a new FoxPro database.

  2. Open a connection to IBM Cloud Object Storage 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 IBM Cloud Object Storage 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 IBM Cloud Object Storage ODBC Driver to get started:

 Download Now

Learn more:

IBM Cloud Object Storage Icon IBM Cloud Object Storage ODBC Driver

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

Access IBM Cloud Object Storage data like you would a database - read, write, and update IBM Cloud Object Storage IBMCloudObject, etc. through a standard ODBC Driver interface.

In this article

Related articles