Class: DB::MariaDB::Native::Result

Inherits:
FFI::Pointer
  • Object
show all
Defined in:
lib/db/mariadb/native/result.rb

Overview

A result set from a database query with row iteration and type casting.

Instance Method Summary collapse

Constructor Details

#initialize(connection, types = {}, address) ⇒ Result

Initialize a new result set wrapper.



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# File 'lib/db/mariadb/native/result.rb', line 25

def initialize(connection, types = {}, address)
  super(address)
  
  @connection = connection
  @fields = nil
  @types = types
  @casts = nil
end

Instance Method Details

#cast!(row) ⇒ Object

Cast row values to appropriate Ruby types.



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# File 'lib/db/mariadb/native/result.rb', line 79

def cast!(row)
  @casts ||= self.field_types
  
  row.size.times do |index|
    if cast = @casts[index]
      row[index] = cast.parse(row[index])
    end
  end
  
  return row
end

#each ⇒ Object

Iterate over each row in the result set.



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# File 'lib/db/mariadb/native/result.rb', line 94

def each
  row = FFI::MemoryPointer.new(:pointer)
  field_count = self.field_count
  
  while true
    status = Native.mysql_fetch_row_start(row, self)
    
    while status != 0
      @connection.wait_for(status)
      
      status = Native.mysql_fetch_row_cont(row, self, status)
    end
    
    pointer = row.read_pointer
    
    if pointer.null?
      break
    else
      yield cast!(pointer.get_array_of_string(0, field_count))
    end
  end
  
  @connection.check_error!("Reading recordset")
end

#field_count ⇒ Object

Get the number of fields in this result set.



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# File 'lib/db/mariadb/native/result.rb', line 36

def field_count
  Native.mysql_num_fields(self)
end

#field_names ⇒ Object Also known as: keys

Get the field names for this result set.



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# File 'lib/db/mariadb/native/result.rb', line 56

def field_names
  fields.map(&:name)
end

#field_types ⇒ Object

Get the type converters for each field.



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# File 'lib/db/mariadb/native/result.rb', line 62

def field_types
  fields.map{|field| @types[field.type]}
end

#fields ⇒ Object

Get the field metadata for this result set.



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# File 'lib/db/mariadb/native/result.rb', line 42

def fields
  unless @fields
    pointer = Native.mysql_fetch_fields(self)
    
    @fields = field_count.times.map do |index|
      Field.new(pointer +  index * Field.size)
    end
  end
  
  return @fields
end

#map(&block) ⇒ Object

Map over each row in the result set.



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# File 'lib/db/mariadb/native/result.rb', line 123

def map(&block)
  results = []
  
  self.each do |row|
    results << yield(row)
  end
  
  return results
end

#row_count ⇒ Object Also known as: count

Get the number of rows in this result set. In the context of unbuffered queries, this is the number of rows that have been fetched so far.



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# File 'lib/db/mariadb/native/result.rb', line 69

def row_count
  Native.mysql_num_rows(self)
end

#to_a ⇒ Object

Convert the entire result set to an array.



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# File 'lib/db/mariadb/native/result.rb', line 135

def to_a
  rows = []
  
  self.each do |row|
    rows << row
  end
  
  return rows
end