isIdCurrent             package:RSQLite             R Documentation

_C_h_e_c_k _w_h_e_t_h_e_r _a_n _d_b_O_b_j_e_c_t_I_d _h_a_n_d_l_e _o_b_j_e_c_t _i_s _v_a_l_i_d _o_r _n_o_t

_D_e_s_c_r_i_p_t_i_o_n:

     Support function that verifies that an dbObjectId holding a
     reference to a foreign object is still valid for communicating
     with the RDBMS

_U_s_a_g_e:

     isIdCurrent(obj)

_A_r_g_u_m_e_n_t_s:

     obj: any `dbObjectId' (e.g., `dbDriver', `dbConnection',
          `dbResult'). 

_D_e_t_a_i_l_s:

     `dbObjectId' are R/S-Plus remote references to foreign (C code)
     objects. This introduces differences to the object's semantics
     such as persistence (e.g., connections may be closed
     unexpectedly), thus this function provides a minimal verification
     to ensure  that the foreign object being referenced can be
     contacted.

_V_a_l_u_e:

     a logical scalar.

_S_e_e _A_l_s_o:

     `dbDriver' `dbConnect' `dbSendQuery' `dbGetQuery' `fetch'

_E_x_a_m_p_l_e_s:

     cursor <- dbSendQuery(con, sql.statement)
     isIdCurrent(cursor)

