CAST_TO_BINARY_DOUBLE

The CAST_TO_BINARY_DOUBLE function converts a BINARY_DOUBLE value represented in RAW binary format to a BINARY_DOUBLE value.

Syntax

UTL_RAW.CAST_TO_BINARY_DOUBLE (
   r          IN RAW
   endianess  IN PLS_INTEGER DEFAULT 1)
RETURN BINARY_DOUBLE;

Parameters

Return value

A BINARY_DOUBLE value.

Considerations

• If the RAW parameter exceeds 8 bytes, only the first 8 bytes are used, and the remaining bytes are ignored. If the result is -0, +0 is returned. If the result is NaN, the returned value is BINARY_DOUBLE_NAN.

• If the RAW parameter is less than 8 bytes, an exception VALUE_ERROR is raised.

• The following table lists the mapping between an 8-byte BINARY_DOUBLE value and the IEEE 754 double-precision format:

  byte 0: bit 63 ~ bit 56
  byte 1: bit 55 ~ bit 48
  byte 2: bit 47 ~ bit 40
  byte 3: bit 39 ~ bit 32
  byte 4: bit 31 ~ bit 24
  byte 5: bit 23 ~ bit 16
  byte 6: bit 15 ~ bit  8
  byte 7: bit  7 ~ bit  0
  

• The endianess parameter describes how the bytes of a BINARY_DOUBLE value are mapped to the bytes of the RAW parameter, as shown in the following matrix. Here, rb0 to rb7 represent the bytes of the RAW parameter, and db0 to db7 represent the bytes of the BINARY_DOUBLE value.

  endianess	rb0	rb1	rb2	rb3	rb4	rb5	rb6	rb7
  big_endian	db0	db1	db2	db3	db4	db5	db6	db7
  little_endian	db7	db6	db5	db4	db3	db2	db1	db0

• For machine-endian, the 8 bytes of the RAW parameter are directly copied to the returned BINARY_DOUBLE value. If you specify big_endian on a big-endian machine or little_endian on a little-endian machine, the result is the same.

Examples

obclient> SELECT UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF') FROM DUAL;
+---------------------------------------------------+
| UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF') |
+---------------------------------------------------+
|                           3.4750462962832636E-308 |
+---------------------------------------------------+
1 row in set

obclient> SELECT UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF', 1) FROM DUAL;
+-----------------------------------------------------+
| UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF',1) |
+-----------------------------------------------------+
|                             3.4750462962832636E-308 |
+-----------------------------------------------------+
1 row in set

obclient> SELECT UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF', 2) FROM DUAL;
+-----------------------------------------------------+
| UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF',2) |
+-----------------------------------------------------+
|                                                 Nan |
+-----------------------------------------------------+
1 row in set

obclient> SELECT UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF', 3) FROM DUAL;
+-----------------------------------------------------+
| UTL_RAW.CAST_TO_BINARY_DOUBLE('0018FCFF18FCFFFF',3) |
+-----------------------------------------------------+
|                                                 Nan |
+-----------------------------------------------------+
1 row in set