FNC_TblOpGetExternalQuery Function | C Library Functions | Teradata Vantage - FNC_TblOpGetExternalQuery - Advanced SQL Engine - Teradata Database

Purpose

Generates the text query string for the foreign server and returns the interface version that is currently supported.

Syntax

void
FNC_TblOpGetExternalQuery(FNC_TblOpColumnDef_t *colDefs,
                          ServerType             serverType,
                          ExtOpSetType           opSet,
                          int                  *interfaceVersion,
                          unsigned char       **extQryPtr,
                          unsigned int         *extQryLenPtr)

FNC_TblOpColumnDef_t *colDefs

IN parameter

A list of column definitions that may occur in a WHERE clause by the foreign server.

ServerType serverType

IN parameter

ServerType is defined as follows:

typedef enum
{
   ANSISQL = 1,
   HADOOP = 2
} serverType_et;

typedef int ServerType;

• If ANSI SQL, the entire subquery for the table of the foreign server is returned.
• If HADOOP, only the WHERE clause portion of the query is returned.

ExtOpSetType opSet

IN parameter

A set of valid operators supported on the foreign server.

ExOpSetType is defined as follows:

typedef enum
{
   Eq_ET,
   Ne_ET,
   Gt_ET,
   Le_ET,
   Lt_ET,
   And_ET,
   Or_ET,
   Not_ET,
   Between_ET,
   In_ET,
   NotIn_ET,
   Ge_ET,
   Like_ET
} extoptype_et;

typedef BYTE ExtOpType;
typedef unsigned int ExtOpSet;

typedef struct ExtOpSetType {
   ExtOpSet ExtOpSetList;
} ExtOpSetType;

int *interfaceVersion

IN/OUT parameter

A pointer to the interface version:

• The caller passes in the desired interface version as the argument.
• The routine returns the actual interface version that is currently returns the actual interface version that is currently

unsigned char **extQryLenPtr

OUT parameter

A pointer to the generated text query string for the foreign server. The query string is null-terminated.

unsigned int *extQryLenPtr

OUT parameter

A pointer to the length of the external query (in bytes).

Usage Notes

This routine is callable on a PE vproc only by a table operator.