# tdbcpostgres.tcl -- # # Class definitions and Tcl-level methods for the tdbc::postgres bridge. # # Copyright (c) 2009 by Slawomir Cygan # # See the file "license.terms" for information on usage and redistribution # of this file, and for a DISCLAIMER OF ALL WARRANTIES. # #------------------------------------------------------------------------------ package require tdbc ::namespace eval ::tdbc::mypostgres { namespace export connection datasources drivers } #------------------------------------------------------------------------------ # # tdbc::postgres::connection -- # # Class representing a connection to a Postgres database. # #------------------------------------------------------------------------------- ::oo::class create ::tdbc::postgres::connection { superclass ::tdbc::connection # The constructor is written in C. It takes alternating keywords # and values pairs as its arguments. (See the manual page for the # available options.) # The 'statementCreate' method delegates to the constructor of the # statement class forward statementCreate ::tdbc::postgres::statement create # The 'prepareCall' method gives a portable interface to prepare # calls to stored procedures. It delegates to 'prepare' to do the # actual work. method preparecall {call} { regexp {^[[:space:]]*(?:([A-Za-z_][A-Za-z_0-9]*)[[:space:]]*=)?(.*)} \ $call -> varName rest if {$varName eq {}} { my prepare \\{$rest\\} } else { my prepare \\{:$varName=$rest\\} } } # The 'init', 'begintransaction', 'commit, 'rollback', 'tables' # and 'columns' methods are implemented in C. } #------------------------------------------------------------------------------ # # tdbc::postgres::statement -- # # The class 'tdbc::postgres::statement' models one statement against a # database accessed through a Postgres connection # #------------------------------------------------------------------------------ ::oo::class create ::tdbc::postgres::statement { superclass ::tdbc::statement # The 'resultSetCreate' method forwards to the constructor of the # result set. forward resultSetCreate ::tdbc::postgres::resultset create # Methods implemented in C: # # constructor connection SQLCode # The constructor accepts the handle to the connection and the SQL code # for the statement to prepare. It creates a subordinate namespace to # hold the statement's active result sets, and then delegates to the # 'init' method, written in C, to do the actual work of preparing the # statement. # params # Returns descriptions of the parameters of a statement. # paramtype paramname ?direction? type ?precision ?scale?? # Declares the type of a parameter in the statement } #------------------------------------------------------------------------------ # # tdbc::postgres::resultset -- # # The class 'tdbc::postgres::resultset' models the result set that is # produced by executing a statement against a Postgres database. # #------------------------------------------------------------------------------ ::oo::class create ::tdbc::postgres::resultset { superclass ::tdbc::resultset # The 'nextresults' method is stubbed out; tdbcpostgres does not # allow a single call to return multiple results. method nextresults {} { while {[my nextdict rubbish]} {} return 0 } # Methods implemented in C include: # constructor statement ?dictionary? # -- Executes the statement against the database, optionally providing # a dictionary of substituted parameters (default is to get params # from variables in the caller's scope). # columns # -- Returns a list of the names of the columns in the result. # nextdict # -- Stores the next row of the result set in the given variable in # the caller's scope as a dictionary whose keys are # column names and whose values are column values, or else # as a list of cells. # nextlist # -- Stores the next row of the result set in the given variable in # the caller's scope as a list of cells. # rowcount # -- Returns a count of rows affected by the statement, or -1 # if the count of rows has not been determined. }