16.20 - FNC_MBRGetValue - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL External Routine Programming

Product
Advanced SQL Engine
Teradata Database
Release Number
16.20
Release Date
April 2020
Content Type
Programming Reference
Publication ID
B035-1147-162K
Language
English (United States)

Purpose

Returns a buffer containing four double precision values representing the xmin, ymin, xmax, and ymax coordinates that define an MBR (minimum bounding rectangle) type.

Syntax

void
FNC_MBRGetValue(GEO_HANDLE    mbrHandle,
                double *      mbrBuffer,
                int *         mbrSize  )
GEO_HANDLE mbrHandle
A handle to an MBR type that is defined to be an input parameter to an external routine.
double* mbrBuffer
A pointer to a buffer that will hold the four double precision values that define the MBR.
int* mbrSize
Size in bytes of the value returned in the mbrBuffer buffer.

Usage Notes

FNC_MBRGetValue retrieves the xmin, ymin, xmax, and ymax values of an MBR type. The values are returned in the mbrBuffer as four double precision values. The caller of the function needs to allocate sufficient memory for the mbrBuffer buffer to hold four double precision values.

Example: Using FNC calls to get an MBR type value

The following function takes an MBR type parameter and returns an array of four double precision values representing the xmin, ymin, xmax, and ymax values that define the MBR.

CREATE TYPE MBR_ARRAY AS DOUBLE PRECISION ARRAY[4];
CREATE FUNCTION mbrUDF1(P1 MBR)
RETURNS MBR_ARRAY
NO SQL
PARAMETER STYLE SQL
DETERMINISTIC
LANGUAGE C
EXTERNAL NAME 'CS!mbrUDF1!mbrUDF1.c';

void mbrUDF1 (GEO_HANDLE* mbr_handle,
              ARRAY_HANDLE* resultArray,
              int* indicator_thismbr,
              int* indicator_Result,
              char       sqlstate[6],
              SQL_TEXT   extname[129],
              SQL_TEXT   specific_name[129],
              SQL_TEXT   error_message[257] )
{
     double* mbrBuffer;
     int returnSize;
     int mbrBufferSize;
     array_info_t arrayInfo;
     bounds_t arrayScope[FNC_MAXARRAYDIMENSIONS];
     NullBitVecType    *NullBitVector;

     mbrBufferSize = 4 * SIZEOF_DOUBLE_PRECISION;
     mbrBuffer = (double*)FNC_Malloc(mbrBufferSize);
     /* Get the MBR value */
      FNC_MBRGetValue(*mbr_handle,mbrBuffer,&returnSize); 

      /* get element type information for the ARRAY */
      FNC_GetArrayTypeInfo(*((ARRAY_HANDLE*)resultArray),
                           &arrayInfo,
                           arrayScope);     
     /* Allocate a new NullBitVector */
      NullBitVector = (NullBitVecType*)FNC_malloc(1);

      /* Set array elements within the range. */
      FNC_SetArrayElementsWithMultiValues(
                      *((ARRAY_HANDLE*)resultArray),
                       arrayScope,
                      (void*)mbrBuffer,
                       mbrBufferSize, NullBitVector,1);

    *indicator_Result = 0;
     FNC_free(NullBitVector);
     FNC_free(mbrBuffer);
}