Guida di riferimento per l'utente

ST_MPointFromWKB

ST_MPointFromWKB rileva una rappresentazione WKB di tipo multipunto e un'identità del sistema di riferimento spaziale per restituire un multipunto.

Sintassi

db2gse.ST_MPointFromWKB(WKBMultiPoint Blob(1M), cr db2gse.coordref)

Tipo di ritorno

db2gse.ST_MultiPoint

Esempi

Questo frammento di codifica compila la tabella SPECIES_SITINGS.

La tabella SPECIES_SITINGS viene creata con tre colonne. Le colonne SPECIES e GENUS identificano le righe in modo univoco mentre il multipunto SITINGS memorizza le relative ubicazioni.

CREATE TABLE SPECIES_SITINGS (species  varchar(32),
                              genus varchar(32),
                              sitings  db2gse.ST_MultiPoint);
 
/* Create the SQL insert statement to populate the species, genus and
   sitings. The question marks are parameter markers that
   indicate the species, genus and sitings values that will be retrieved at
   runtime. */
strcpy (wkb_sql,"insert into SPECIES_SITINGS (species,genus,sitings)
values (?,?, db2gse.ST_MPointFromWKB (cast(? as blob(1m)),
db2gse.coordref()..srid(0)))");
 
/* Allocate memory for the SQL statement handle and associate the
   statement handle with the connection handle. */
rc = SQLAllocStmt (handle, &hstmt);
 
/* Prepare the SQL statement for execution. */
rc = SQLPrepare (hstmt, (unsigned char *)wkb_sql, SQL_NTS);
 
/* Bind the varchar species value to the first parameter. */
pcbvalue1 = species_len;
rc = SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR,
   SQL_CHAR, species_len, 0, &species, species_len, &pcbvalue1);
/* Bind the varchar genus value to the second parameter. */
pcbvalue2 = genus_len;
rc = SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR,
   SQL_CHAR, genus_len, 0, &name, genus_len, &pcbvalue2);
 
/* Bind the shape to the third parameter. */
pcbvalue3 = sitings_len;
rc = SQLBindParameter (hstmt, 3, SQL_PARAM_INPUT, SQL_C_BINARY,
     SQL_BLOB, sitings_len, 0, sitings_wkb, sitings_len, &pcbvalue3);
 
/* Execute the insert statement. */
rc = SQLExecute (hstmt);


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