Provided by: tcl8.6-tdbc_1.0.0-1_amd64 bug

NAME

       tdbc::resultset - TDBC result set object

SYNOPSIS

       package require tdbc 1.0
       package require tdbc::driver version

       tdbc::driver::connection create db ?-option value...?

       set stmt [db prepare sql-code]
       set resultset [$stmt execute ?args...?]

       $resultset columns
       $resultset rowcount
       $resultset nextrow ?-as lists|dicts? ?--? varname
       $resultset nextlist varname
       $resultset nextdict varname
       $resultset nextresults
       $resultset allrows ?-as lists|dicts? ?-columnsvariable name? ?--?
       $resultset foreach ?-as lists|dicts? ?-columnsvariable name? ?--? varname script
       $resultset close
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DESCRIPTION

       Every  database driver for TDBC (Tcl DataBase Connectivity) implements a result set object
       that represents a the results  returned  from  executing  SQL  statement  in  a  database.
       Instances  of  this  object  are  created  by  executing  the  execute object command on a
       statement object.

       The columns obect command returns a list of the names of the columns in  the  result  set.
       The  columns  will  appear  in  the  same order as they appeared in the SQL statement that
       performed the database query. If the SQL statement does not return a set of  columns  (for
       instance,  if  it  is  an  INSERT,  UPDATE, or DELETE statement), the columns command will
       return an empty list.

       The rowcount object command returns the number of rows in the database that were  affected
       by  the  execution  of an INSERT, UPDATE or DELETE statement.  For a SELECT statement, the
       row count is unspecified.

       The nextlist object command sets the variable given by varname in the  caller's  scope  to
       the  next  row  of  the  results,  expressed  as  a list of column values. NULL values are
       replaced by empty strings. The columns of the result row appear in the same order in which
       they  appeared  on  the  SELECT  statement.  The  return of nextlist is 1 if the operation
       succeeded, and 0  if the end of the result set was reached.

       The nextdict object command sets the variable given by varname in the  caller's  scope  to
       the  next  row of the results, expressed as a dictionary. The dictionary's keys are column
       names, and the values are the values of those columns in the row. If a column's  value  in
       the  row  is  NULL,  its  key  is  omitted  from  the  dictionary.  The keys appear in the
       dictionary in the same order in which the columns appeared on the  SELECT  statement.  The
       return  of  nextdict  is 1 if the operation succeeded, and 0  if the end of the result set
       was reached.

       The nextrow object command is precisely equivalent to  the  nextdict  or  nextlist  object
       command, depending on whether -as dicts (the default) or -as lists is specified.

       Some  databases  support  the  idea  of  a  single statement that returns multiple sets of
       results. The nextresults object command is  executed,  typically  after  the  nextlist  of
       nextdict object command has returned 0, to advance to the next result set. It returns 1 if
       there is another result set to process, and 0 if the result set  just  processed  was  the
       last.  After  calling  nextresults  and getting the return value of 1, the caller may once
       again call columns to get the column descriptions of the next result set, and then  return
       to  calling  nextdict  or  nextlist  to process the rows of the next result set.  It is an
       error to call columns, nextdict, nextlist or nextrow after nextresults has returned 0.

       The allrows object command sets the variable designated by the -columnsvariable option (if
       present)  to the result of the columns object command. It then executes the nextrow object
       command repeatedly until the end of the result set is reached. If  nextresults  returns  a
       nonzero  value,  it  executes  the  above  two steps (columns followed by iterated nextrow
       calls) as long as further  results  are  available.  The  rows  returned  by  nextrow  are
       assembled  into  a  Tcl  list and become the return value of the allrows command; the last
       value returned from columns is what the application will see in -columnsvariable.

       The foreach object command sets the variable designated by the -columnsvariable option (if
       present)  to the result of the columns object command. It then executes the nextrow object
       command repeatedly until the end of the result set is reached, storing the successive rows
       in  the variable designated by varName. For each row, it executes the given script. If the
       script terminates with an error, the  error  is  reported  by  the  foreach  command,  and
       iteration  stops.  If  the  script  performs  a  break operation, the iteration terminates
       prematurely. If the script performs a continue operation, the iteration  recommences  with
       the  next  row.   If  the  script  performs  a return, results are the same as if a script
       outside the control of foreach had returned. Any other unusual return code terminates  the
       iteration and is reported from the foreach.

       Once nextrow returns 0, the foreach object command tries to advance to the next result set
       using nextresults.  If nextresults returns 1, the above steps (columns and  nextrow,  with
       script invocation) are repeated as long as more result sets remain. The script will always
       see the correct description of the columns of the  current  result  set  in  the  variable
       designated  byt  -columnsvariable.  At  the  end  of  the call, the variable designated by
       -columnsvariable will have the description of the columns of the last result set.

       The close object command deletes the result set and frees any associated system resources.

SEE ALSO

       encoding(3tcl),      tdbc(3tcl),      tdbc::connection(3tcl),       tdbc::statement(3tcl),
       tdbc::tokenize(3tcl)

KEYWORDS

       TDBC,  SQL,  database,  connectivity,  connection,  resultset,  statement, bound variable,
       stored procedure, call

COPYRIGHT

       Copyright (c) 2008 by Kevin B. Kenny.