RODBCtables              package:RODBC              R Documentation

_O_p_e_r_a_t_i_o_n_s _o_n _T_a_b_l_e_s _i_n _O_D_B_C _d_a_t_a_b_a_s_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Operations on tables in ODBC databases.

_U_s_a_g_e:

     sqlClear(channel, sqtable, errors = TRUE)

     sqlDrop(channel, sqtable, errors = TRUE)

     sqlColumns(channel, sqtable, errors = FALSE, as.is = TRUE,
                special = FALSE)

     sqlPrimaryKeys(channel, sqtable, errors = FALSE, as.is = TRUE)

_A_r_g_u_m_e_n_t_s:

 channel: connection object as returned by 'odbcConnect'.

 sqtable: character: a database table name accessible from the
          connected dsn.

  errors: if TRUE halt and display error, else return -1

   as.is: as in 'sqlGetResults'.

 special: return only the column(s) needed to specify a row uniquely. 
          Depending on the database, there might be none.

_D_e_t_a_i_l_s:

     'sqlClear' deletes the content of the table 'sqtable'.  No
     confirmation is requested.

     'sqlDrop' removes the table 'sqtable'.  No confirmation is
     requested.

     'sqlColumns' and 'sqlPrimaryKeys' return information as data
     frames.  The column names are not constant across ODBC versions so
     the data should be accessed by column number.  The argument
     'special' to 'sqlColumns' returns the columns needed to specify a
     row uniquely.  This is intended to form the basis of a WHERE
     clause for updates (see 'sqlUpdate').

_V_a_l_u_e:

     A data frame on success, or character/numeric on error depending
     on the 'errors' parameter.  If no data is returned, either a
     zero-row data frame or an error. (For example, if there are no
     primary keys or special column(s) in this table an empty data
     frame is returned, but if primary keys are not supported by the
     DBMS, an error code results.)

_A_u_t_h_o_r(_s):

     Michael Lapsley and Brian Ripley

_S_e_e _A_l_s_o:

     'odbcConnect', 'sqlQuery', 'sqlFetch', 'sqlSave', 'sqlTables',
     'odbcGetInfo'

_E_x_a_m_p_l_e_s:

     ## Not run: 
     ## example results from MySQL
     data(USArrests) # R < 2.0.0 only
     channel <- odbcConnect("test")
     sqlDrop(channel, "USArrests", errors = FALSE) # precautionary
     sqlSave(channel, USArrests)
     sqlColumns(channel, "USArrests")
     sqlColumns(channel, "USArrests", special = TRUE)
     sqlPrimaryKeys(channel, "USArrests")
     sqlColumns(channel, "USArrests")
     ##   Table_cat Table_schema Table_name Column_name Data_type Type_name
     ## 1                         USArrests    rownames        12   varchar
     ## 2                         USArrests      murder         8    double
     ## 3                         USArrests     assault         4   integer
     ## 4                         USArrests    urbanpop         4   integer
     ## 5                         USArrests        rape         8    double
     ##   Column_size Buffer_length Decimal_digits Num_prec_radix Nullable Remarks
     ## 1         255           255           <NA>           <NA>        0
     ## 2          22             8             31             10        1
     ## 3          11             4              0             10        1
     ## 4          11             4              0             10        1
     ## 5          22             8             31             10        1
     sqlColumns(channel, "USArrests", special = TRUE)
     ##   Scope Column_name Data_type Type_name Precision Length Scale
     ## 1     2    rownames        12   varchar         0      0     0
     ##   Pseudo_column
     ## 1             1
     sqlPrimaryKeys(channel, "USArrests")
     ##   Table_qualifer Table_owner Table_name Column_name Key_seq Pk_name
     ## 1           <NA>        <NA>  USArrests    rownames       1 PRIMARY
     sqlClear(channel, "USArrests")
     sqlDrop(channel, "USArrests")
     close(channel)
     ## End(Not run)

