CAST_TO_BINARY_DOUBLE

The CAST_TO_BINARY_DOUBLE function converts a BINARY_DOUBLE value in the binary RAW representation into 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 values

A BINARY_DOUBLE value is returned.

Considerations

• If the RAW parameter exceeds 8 bytes in length, 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 return value is BINARY_DOUBLE_NAN.

• If the RAW parameter is less than 8 bytes in length, the VALUE_ERROR exception is thrown.

• The following list shows 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 BINARY_DOUBLE bytes are mapped to RAW bytes, as shown in the following matrix. rb0–rb7 are the RAW bytes, and db0–db7 are the BINARY_DOUBLE bytes.

  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 copied directly into the return BINARY_DOUBLE value. Passing big_endian on a big-endian machine has the same effect as passing little_endian on a little-endian machine.

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