Changed layout to support tagging and branching

1 files changed, 218 insertions, 0 deletions

diff --git a/lib/sqlite3/statement.rb b/lib/sqlite3/statement.rb
new file mode 100644
index 0000000..8d2e3d5
--- /dev/null
+++ b/lib/sqlite3/statement.rb
@@ -0,0 +1,218 @@
+#--
+# =============================================================================
+# Copyright (c) 2004, Jamis Buck (jgb3@email.byu.edu)
+# All rights reserved.
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+#     * Redistributions of source code must retain the above copyright notice,
+#       this list of conditions and the following disclaimer.
+# 
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+# 
+#     * The names of its contributors may not be used to endorse or promote
+#       products derived from this software without specific prior written
+#       permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =============================================================================
+#++
+
+require 'sqlite3/errors'
+require 'sqlite3/resultset'
+
+class String
+  def to_blob
+    SQLite3::Blob.new( self )
+  end
+end
+
+module SQLite3
+
+  # A class for differentiating between strings and blobs, when binding them
+  # into statements.
+  class Blob < String; end
+
+  # A statement represents a prepared-but-unexecuted SQL query. It will rarely
+  # (if ever) be instantiated directly by a client, and is most often obtained
+  # via the Database#prepare method.
+  class Statement
+
+    # This is any text that followed the first valid SQL statement in the text
+    # with which the statement was initialized. If there was no trailing text,
+    # this will be the empty string.
+    attr_reader :remainder
+
+    # The underlying opaque handle used to access the SQLite @driver.
+    attr_reader :handle
+
+    # Create a new statement attached to the given Database instance, and which
+    # encapsulates the given SQL text. If the text contains more than one
+    # statement (i.e., separated by semicolons), then the #remainder property
+    # will be set to the trailing text.
+    def initialize( db, sql, utf16=false )
+      @db = db
+      @driver = @db.driver
+      result, @handle, @remainder = @driver.prepare( @db.handle, sql )
+      Error.check( result, @db )
+    end
+
+    def close
+      @driver.finalize( @handle )
+    end
+
+    # Binds the given variables to the corresponding placeholders in the SQL
+    # text.
+    #
+    # See Database#execute for a description of the valid placeholder
+    # syntaxes.
+    #
+    # Example:
+    #
+    #   stmt = db.prepare( "select * from table where a=? and b=?" )
+    #   stmt.bind_params( 15, "hello" )
+    #
+    # See also #execute, #bind_param, Statement#bind_param, and
+    # Statement#bind_params.
+    def bind_params( *bind_vars )
+      index = 1
+      bind_vars.each do |var|
+        if Hash === var
+          var.each { |key, val| bind_param key, val }
+        else
+          bind_param index, var
+          index += 1
+        end
+      end
+    end
+
+    # Binds value to the named (or positional) placeholder. If +param+ is a
+    # Fixnum, it is treated as an index for a positional placeholder.
+    # Otherwise it is used as the name of the placeholder to bind to.
+    #
+    # See also #bind_params.
+    def bind_param( param, value )
+      if Fixnum === param
+        case value
+          when Integer then
+            @driver.bind_int( @handle, param, value )
+          when Numeric then
+            @driver.bind_double( @handle, param, value.to_f )
+          when Blob then
+            @driver.bind_blob( @handle, param, value )
+          when nil then
+            @driver.bind_null( @handle, param )
+          else
+            @driver.bind_text( @handle, param, value )
+        end
+      else
+        index = @driver.bind_parameter_index(
+          @handle, param.to_s )
+        raise Exception, "no such bind parameter '#{param}'" if index == 0
+        bind_param index, value
+      end
+    end
+
+    # Execute the statement. This creates a new ResultSet object for the
+    # statement's virtual machine. If a block was given, the new ResultSet will
+    # be yielded to it; otherwise, the ResultSet will be returned.
+    #
+    # Any parameters will be bound to the statement using #bind_params.
+    #
+    # Example:
+    #
+    #   stmt = db.prepare( "select * from table" )
+    #   stmt.execute do |result|
+    #     ...
+    #   end
+    #
+    # See also #bind_params, #execute!.
+    def execute( *bind_vars )
+      @driver.reset( @handle ) if @results
+
+      bind_params *bind_vars unless bind_vars.empty?
+      @results = ResultSet.new( @db, self )
+
+      if block_given?
+        yield @results
+      else
+        return @results
+      end
+    end
+
+    # Execute the statement. If no block was given, this returns an array of
+    # rows returned by executing the statement. Otherwise, each row will be
+    # yielded to the block.
+    #
+    # Any parameters will be bound to the statement using #bind_params.
+    #
+    # Example:
+    #
+    #   stmt = db.prepare( "select * from table" )
+    #   stmt.execute! do |row|
+    #     ...
+    #   end
+    #
+    # See also #bind_params, #execute.
+    def execute!( *bind_vars )
+      result = execute( *bind_vars )
+      rows = [] unless block_given?
+      while row = result.next
+        if block_given?
+          yield row
+        else
+          rows << row
+        end
+      end
+      rows
+    end
+
+    # Return an array of the column names for this statement. Note that this
+    # may execute the statement in order to obtain the metadata; this makes it
+    # a (potentially) expensive operation.
+    def columns
+      get_metadata unless @columns
+      return @columns
+    end
+
+    # Return an array of the data types for each column in this statement. Note
+    # that this may execute the statement in order to obtain the metadata; this
+    # makes it a (potentially) expensive operation.
+    def types
+      get_metadata unless @types
+      return @types
+    end
+
+    # A convenience method for obtaining the metadata about the query. Note
+    # that this will actually execute the SQL, which means it can be a
+    # (potentially) expensive operation.
+    def get_metadata
+      @columns = []
+      @types = []
+
+      column_count = @driver.column_count( @handle )
+      column_count.times do |column|
+        @columns << @driver.column_name( @handle, column )
+        @types << @driver.column_decltype( @handle, column )
+      end
+
+      @columns.freeze
+      @types.freeze
+    end
+    private :get_metadata
+
+  end
+
+end