Example: Using FNC_GetXMLBlob to Retrieve an XML Type Input Value - Analytics Database - Teradata Vantage

The following function takes an XML type parameter, retrieves the BLOB representation of the XML, and returns the BLOB to the user.

CREATE FUNCTION xmlUDF5(P1 XML)
RETURNS BLOB AS LOCATOR
NO SQL
PARAMETER STYLE SQL
DETERMINISTIC
LANGUAGE C
EXTERNAL NAME 'CS!xmlUDF5!xmlUDF5.c';

void xmlUDF5(XML_HANDLE  *xml_handle,
              LOB_RESULT_LOCATOR *return_blob,
              int*       indicator_thisXML,
              int*       indicator_returnLOB,
              char       sqlstate[6],
              SQL_TEXT   extname[129],
              SQL_TEXT   specific_name[129],
              SQL_TEXT   error_message[257] )
{
     LOB_LOCATOR xmlBlob;
     BYTE buffer[100000];
     LOB_CONTEXT_ID id;
     FNC_LobLength_t actlen;
     int trunc_err = 0;
     FNC_XMLSize_t xmlSize;
     int numLobs;

     /* Get the XML Size */
      FNC_GetXMLInfo(*xml_handle, &xmlSize, &numLobs); 

     if(numLobs ==1 )
     {
    
      /* Read XML value */ 
       FNC_GetXMLBlob(*xml_handle,&xmlClob); 

      /* Use LOB FNC calls to read the XML BLOB and return it */                                                                                                                           
       FNC_LobOpen(*xmlBlob, &id, 0, 0);
       while( FNC_LobRead(id, buffer, 100000, &actlen) == 0 && !trunc_err)
          trunc_err = FNC_LobAppend(*return_blob, buffer, actlen, &actlen);

       FNC_LobClose(id);
      *indicator_returnLob = 0;
    }
 }