| # 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. | |
| } | |