FNC_SetStructuredAttributeByNdx | C Library Functions | Teradata Vantage - FNC_SetStructuredAttributeByNdx - Advanced SQL Engine - Teradata Database

Set the value of a non-LOB attribute of a structured type.

Syntax

void
FNC_SetStructuredAttributeByNdx ( UDT_HANDLE  udtHandle,
                                  int         attributeIndex,
                                  void       *newValue,
                                  int         nullIndicator,
                                  int         length )

Syntax Elements

udtHandle

the handle to a structured UDT.

attributeIndex

the index of an attribute at the top-most level of the UDT.

The range of values is from 0 to i-1, where 0 is the index of the first attribute in the UDT and i is the number of non-nested attributes in the UDT.

For example, consider a structured UDT called PointUDT that has two attributes: the first attribute is called x and the second attribute is called y. To set the x value, use an index of 0. Similarly, to set the y value, use an index of 1.

newValue

a pointer to a buffer containing the new value for the attribute.

If the specified attribute is a structured UDT, you can use the nullIndicator argument to set the attribute to null, but FNC_SetStructuredAttributeByNdx ignores the newValue and length arguments.

nullIndicator

whether to set the attribute to null.

If the value of nullIndicator is...

• -1, then FNC_SetStructuredAttributeByNdx sets the attribute to null.

  The newValue argument is ignored.

• 0, then FNC_SetStructuredAttributeByNdx sets the attribute to the value pointed to by newValue.

length

the size in bytes of the newValue buffer.

If the specified attribute is a structured UDT, you can use the nullIndicator argument to set the attribute to null, but FNC_SetStructuredAttributeByNdx ignores the newValue and length arguments.

Usage Notes

• To define the buffer pointed to by newValue, use the C data type that maps to the underlying type of the attribute. For example, if the distinct type represents an SQL INTEGER data type, you can define the buffer like this:

  INTEGER value;
  value = 2048;

  For information on the C data types you can use, see C Data Types.

  If the underlying type of the attribute is a character string, and the newValue character string is shorter than the size defined for the type, FNC_SetStructuredAttributeByNdx fills to the right with spaces.

  Because character data types allow embedded null characters, do not include null termination characters in the value you pass in for the length argument.

  To guarantee that the value you pass in for the length argument matches the length of the data type in Vantage, use these macros defined in the sqltypes_td.h header file.

  Macro	Description
  SIZEOF_CHARACTER_LATIN(len) SIZEOF_CHARACTER_KANJISJIS(len) SIZEOF_CHARACTER_KANJI1(len) SIZEOF_CHARACTER_UNICODE(len)	Returns the length in bytes of a CHARACTER data type of len characters. For example, the following returns a length of 6 (3 * 2 = 6): SIZEOF_CHARACTER_UNICODE(3)
  SIZEOF_VARCHAR_LATIN(len) SIZEOF_VARCHAR_KANJISJIS(len) SIZEOF_VARCHAR_KANJI1(len) SIZEOF_VARCHAR_UNICODE(len)	Returns the length in bytes of a VARCHAR data type of len characters. For example, the following returns a length of 6 (3 * 2 = 6): SIZEOF_VARCHAR_UNICODE(3)
  SIZEOF_BYTE(len) SIZEOF_VARBYTE(len)	Returns the length in bytes of the specified BYTE or VARBYTE data type, where len specifies the number of values.
  SIZEOF_GRAPHIC(len) SIZEOF_VARGRAPHIC(len)	Returns the length in bytes of the specified CHARACTER(n) CHARACTER SET GRAPHIC or VARCHAR(n) CHARACTER SET GRAPHIC data type, where len specifies the number of values.
  SIZEOF_BYTEINT SIZEOF_SMALLINT SIZEOF_INTEGER SIZEOF_BIGINT SIZEOF_REAL SIZEOF_DOUBLE_PRECISION SIZEOF_FLOAT SIZEOF_DECIMAL1 SIZEOF_DECIMAL2 SIZEOF_DECIMAL4 SIZEOF_DECIMAL8 SIZEOF_DECIMAL16 SIZEOF_NUMERIC1 SIZEOF_NUMERIC2 SIZEOF_NUMERIC4 SIZEOF_NUMERIC8 SIZEOF_NUMERIC16 SIZEOF_NUMBER	Returns the length in bytes of the specified numeric data type. For NUMBER, the length returned is 4 + 2 + 17 = 23 bytes since Vantage allocates max length (17 bytes) for the mantissa.
  SIZEOF_DATE SIZEOF_ANSI_Time SIZEOF_ANSI_Time_WZone SIZEOF_TimeStamp SIZEOF_TimeStamp_WZone	Returns the length in bytes of the specified DateTime type.
  SIZEOF_INTERVAL_YEAR SIZEOF_IntrvlYtoM SIZEOF_INTERVAL_MONTH SIZEOF_INTERVAL_DAY SIZEOF_IntrvlDtoH SIZEOF_IntrvlDtoM SIZEOF_IntrvlDtoS SIZEOF_HOUR SIZEOF_IntrvlHtoM SIZEOF_IntrvlHtoS SIZEOF_MINUTE SIZEOF_IntrvlMtoS SIZEOF_IntrvlSec	Returns the length in bytes of the specified Interval type.

• Setting the Value of a Nested Attribute
  To set the value of an attribute that is nested in the hierarchy of a UDT that is defined to be a return value to a UDF, UDM, or external stored procedure, follow these steps:

  1. Call FNC_GetStructuredAttributeByNdx to obtain the UDT handle of the next structured UDT attribute in the path to the target attribute.

     Repeat this step, passing in the newly obtained UDT handle as the udtHandle argument, n-2 times, where n is the nesting level of the target attribute.

  2. Call FNC_SetStructuredAttributeByNdx, passing in the UDT handle of the structured UDT attribute that contains the target attribute.

• An external stored procedure that uses CLIv2 to execute SQL must wait for any outstanding CLIv2 requests to complete before calling this function.