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SQLITE3_VTAB_RHS_VALUE(3)  Library Functions Manual  SQLITE3_VTAB_RHS_VALUE(3)

NAME
     sqlite3_vtab_rhs_value - constraint values in xBestIndex()

SYNOPSIS
     #include <sqlite3.h>

     int
     sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);

DESCRIPTION
     This API may only be used from within the xBestIndex method of a virtual
     table implementation.  The result of calling this interface from outside
     of an xBestIndex method are undefined and probably harmful.

     When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
     the xBestIndex method of a virtual table implementation, with P being a
     copy of the sqlite3_index_info object pointer passed into xBestIndex and
     J being a 0-based index into P->aConstraint[], then this routine attempts
     to set *V to the value of the right-hand operand of that constraint if
     the right-hand operand is known.  If the right-hand operand is not known,
     then *V is set to a NULL pointer.  The sqlite3_vtab_rhs_value(P,J,V)
     interface returns SQLITE_OK if and only if *V is set to a value.  The
     sqlite3_vtab_rhs_value(P,J,V) inteface returns SQLITE_NOTFOUND if the
     right-hand side of the J-th constraint is not available.  The
     sqlite3_vtab_rhs_value() interface can return an result code other than
     SQLITE_OK or SQLITE_NOTFOUND if something goes wrong.

     The sqlite3_vtab_rhs_value() interface is usually only successful if the
     right-hand operand of a constraint is a literal value in the original SQL
     statement.  If the right-hand operand is an expression or a reference to
     some other column or a host parameter, then sqlite3_vtab_rhs_value() will
     probably return SQLITE_NOTFOUND.

     Some constraints, such as SQLITE_INDEX_CONSTRAINT_ISNULL and
     SQLITE_INDEX_CONSTRAINT_ISNOTNULL, have no right-hand operand.  For such
     constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.

     The sqlite3_value object returned in *V is a protected sqlite3_value and
     remains valid for the duration of the xBestIndex method call.  When
     xBestIndex returns, the sqlite3_value object returned by
     sqlite3_vtab_rhs_value() is automatically deallocated.

     The "_rhs_" in the name of this routine is an abbreviation for "Right-
     Hand Side".

IMPLEMENTATION NOTES
     These declarations were extracted from the interface documentation at
     line 9971.

     SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);

SEE ALSO
     sqlite3_bind_blob(3), sqlite3_index_info(3), sqlite3_value(3),
     SQLITE_INDEX_CONSTRAINT_EQ(3), SQLITE_OK(3)

NetBSD 10.99                    August 24, 2023                   NetBSD 10.99