16.20 - Syntax - 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)
void
FNC_GetStructuredAttributeInfo_EON ( UDT_HANDLE             AnyStructuredUdt,
                                     int                    attribute_position,
                                     int                    bufSize,
                                     attribute_info_eon_t  *attributeArray )
UDT_HANDLE AnyStructuredUdt
the handle to a structured UDT that is defined to be an input parameter to an external routine.
int attribute_position
whether this call returns information about one or all of the attributes.
If the value is...
  • 0 or greater, then the value identifies the position of the attribute in the structured UDT for which this call returns information. The position of the first attribute is 0.
  • -1, then this call returns information about all of the attributes.
int bufSize
the size in bytes that was allocated to the attributeArray argument.
attribute_info_eon_t *attributeArray
an array of one or more attribute_info_eon_t structures that describe the requested attribute or attributes in the structured UDT, as specified by attribute_position.
The attribute_info_eon_t structure is defined in sqltypes_td.h as:
typedef struct attribute_info_eon_t
{
   INTEGER_td       attrIndex;
   dtype_et         data_type;
   CHARACTER        attribute_name[FNC_MAXNAMELEN_EON];
   SMALLINT         udt_indicator;
   CHARACTER        udt_type_name[FNC_MAXNAMELEN_EON];
   INTEGER_td       max_length;
   FNC_LobLength_t  lob_length;
   SMALLINT         total_interval_digits;
   SMALLINT         num_fractional_digits;
   charset_et       charset_code;
} attribute_info_eon_t;
where:
  • attrIndex specifies the position of the attribute in the structured type, where the position of the first attribute is 0.
  • data_type specifies the data type of the attribute. The sqltypes_td.h header file defines dtype_et as:
    typedef int dtype_et;

    Valid values are defined by the dtype_en enumeration in sqltypes_td.h. For a list of the valid values, see the dtype[] argument in FNC_CallSP .

  • attribute_name specifies the attribute name.

    For dynamic UDTs with attributes that are defined by column names and no , the attribute name is the column name.

  • udt_indicator specifies whether the attribute is a UDT and if so, which kind:
    • 0 meaning that it is not a UDT.
    • 1 meaning that it is a structured UDT.
    • 2 meaning that it is a distinct UDT.
    • 3 meaning that it is a Teradata proprietary internal UDT.
    • 5 meaning that it is a JSON attribute.
  • udt_type_name specifies the UDT type name associated with the attribute.

    This is meaningful only if the attribute is a UDT.

  • max_length specifies the maximum length in bytes of the value of the attribute.

    If the attribute is a non-LOB type, you can use max_length as the size in bytes of the buffer you need to allocate before you make a call to FNC_GetStructuredAttribute to get the value of the structured attribute.

    If the attribute is a LOB, max_length indicates the LOB_REF length. The lob_length member provides the length of the LOB data itself.

    For a JSON attribute, max_length indicates the maximum possible length of the JSON attribute.

  • lob_length specifies the length of a LOB attribute.

    This is meaningful only if the attribute is a LOB.

    For a JSON attribute, lob_length specifies the maximum possible length of the JSON attribute in bytes if the data is stored as a LOB; otherwise, this value is 0.

    You can use lob_length as the length of the LOB object that you pass to FNC_LobOpen when you establish a read context for the LOB attribute.

  • total_interval_digits specifies the precision of certain attributes. The value of total_interval_digits corresponds to the n value of the following types:
    • DECIMAL(n, m)
    • INTERVAL YEAR(n)
    • INTERVAL YEAR(n) TO MONTH
    • INTERVAL MONTH(n)
    • INTERVAL DAY(n)
    • INTERVAL DAY(n) TO HOUR
    • INTERVAL DAY(n) TO MINUTE
    • INTERVAL DAY(n) TO SECOND(m)
    • INTERVAL HOUR(n)
    • INTERVAL HOUR(n) TO MINUTE
    • INTERVAL HOUR(n) TO SECOND(m)
    • INTERVAL MINUTE(n)
    • INTERVAL MINUTE(n) TO SECOND(m)
    • INTERVAL SECOND(n, m)

    If the data type of the attribute does not appear in the preceding list, total_interval_digits is not meaningful for the attribute.

  • num_fractional_digits specifies the precision or scale of certain attributes. The value of num_fractional_digits corresponds to the m value of the following types:
    • DECIMAL(n, m)
    • TIME(m)
    • TIME(m) WITH TIME ZONE
    • TIMESTAMP(m)
    • TIMESTAMP(m) WITH TIME ZONE
    • INTERVAL DAY(n) TO SECOND(m)
    • INTERVAL HOUR(n) TO SECOND(m)
    • INTERVAL MINUTE(n) TO SECOND(m)
    • INTERVAL SECOND(n, m)

    If the data type of the attribute does not appear in the preceding list, num_fractional_digits is not meaningful for the attribute.

  • charset_code specifies the server character set associated with the attribute.

    This is meaningful only if the attribute is a character type.

    The sqltypes_td.h header file defines charset_et as:
    typedef int charset_et;
    Valid values are defined by the charset_en enumeration in sqltypes_td.h:
    typedef enum charset_en
    {
       UNDEF_CT=0,
       LATIN_CT=1,
       UNICODE_CT=2,
       KANJISJIS_CT=3,
       KANJI1_CT=4
    } charset_en; 

    For a JSON attribute, charset_code is LATIN_CT or UNICODE_CT depending on how the JSON attribute was defined.