The ST_GeomFromWKB() function

The ST_GeomFromWKB() function takes a well-known binary representation and a spatial reference ID to return a geometry object.

The ST_GeomFromWKB() function does not support the ST_GeomCollection.

Syntax

ST_GeomFromWKB(WKB lvarchar, SRID integer)

Return type

ST_Geometry

Example

The following C code fragment contains ODBC functions included with the HCL® OneDB® spatial data type functions that insert data into the lots table.

The lots table was created with two columns: the lot_id, which uniquely identifies each lot, and the lot polygon column, which contains the geometry of each lot:
CREATE TABLE lots (lot_id  integer,
                   lot     ST_MultiPolygon);
The ST_GeomFromWKB() function converts WKB representations into HCL OneDB spatial geometry. The entire INSERT statement is copied into a wkb_sql CHAR string. The INSERT statement contains parameter markers to accept the lot_id and lot data, dynamically:
/* Create the SQL insert statement to populate the lots
     * table. The question marks are parameter markers that indicate
     * the column values that will be inserted at run time. */
    sprintf(sql_stmt,
            "INSERT INTO lots (lot_id, lot) "
            "VALUES(?, ST_GeomFromWKB(?, %d))", srid);

    /* Prepare the SQL statement for execution. */
    rc = SQLPrepare (hstmt, (unsigned char *)sql_stmt, SQL_NTS);

    /* Bind the lot_id to the first parameter. */
    pcbvalue1 = 0;
    rc = SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_SLONG,
                           SQL_INTEGER, 0, 0,
                           &lot_id, 0, &pcbvalue1);

    /* Bind the lot geometry to the second parameter. */
    pcbvalue2 = lot_wkb_len;
    rc = SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_BINARY,
                           SQL_INFX_UDT_LVARCHAR, lot_wkb_len, 0,
                           lot_wkb_buf, lot_wkb_len, &pcbvalue2);

    /* Execute the insert statement. */
    rc = SQLExecute (hstmt);