Class: SQLite3::ResultSet

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/sqlite3/resultset.rb

Overview

The ResultSet object encapsulates the enumerability of a query’s output. It is a simple cursor over the data that the query returns. It will very rarely (if ever) be instantiated directly. Instead, clients should obtain a ResultSet instance via Statement#execute.

Direct Known Subclasses

HashResultSet

Instance Method Summary collapse

Constructor Details

#initialize(db, stmt) ⇒ ResultSet

Create a new ResultSet attached to the given database, using the given sql text.



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# File 'lib/sqlite3/resultset.rb', line 14

def initialize db, stmt
  @db = db
  @stmt = stmt
end

Instance Method Details

#close ⇒ Object

Closes the statement that spawned this result set. Use with caution! Closing a result set will automatically close any other result sets that were spawned from the same statement.



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# File 'lib/sqlite3/resultset.rb', line 65

def close
  @stmt.close
end

#closed? ⇒ Boolean

Queries whether the underlying statement has been closed or not.

Returns:

  • (Boolean) 


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# File 'lib/sqlite3/resultset.rb', line 70

def closed?
  @stmt.closed?
end

#columns ⇒ Object

Returns the names of the columns returned by this result set.



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# File 'lib/sqlite3/resultset.rb', line 80

def columns
  @stmt.columns
end

#each ⇒ Object

Required by the Enumerable mixin. Provides an internal iterator over the rows of the result set.



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# File 'lib/sqlite3/resultset.rb', line 48

def each
  while (node = self.next)
    yield node
  end
end

#each_hash ⇒ Object

Provides an internal iterator over the rows of the result set where each row is yielded as a hash.



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# File 'lib/sqlite3/resultset.rb', line 56

def each_hash
  while (node = next_hash)
    yield node
  end
end

#eof? ⇒ Boolean

Query whether the cursor has reached the end of the result set or not.

Returns:

  • (Boolean) 


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# File 'lib/sqlite3/resultset.rb', line 27

def eof?
  @stmt.done?
end

#next ⇒ Object

Obtain the next row from the cursor. If there are no more rows to be had, this will return nil.

The returned value will be an array, unless Database#results_as_hash has been set to true, in which case the returned value will be a hash.

For arrays, the column names are accessible via the fields property, and the column types are accessible via the types property.

For hashes, the column names are the keys of the hash, and the column types are accessible via the types property.



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# File 'lib/sqlite3/resultset.rb', line 42

def next
  @stmt.step
end

#next_hash ⇒ Object

Return the next row as a hash



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# File 'lib/sqlite3/resultset.rb', line 85

def next_hash
  row = @stmt.step
  return nil if @stmt.done?

  @stmt.columns.zip(row).to_h
end

#reset(*bind_params) ⇒ Object

Reset the cursor, so that a result set which has reached end-of-file can be rewound and reiterated.



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# File 'lib/sqlite3/resultset.rb', line 21

def reset(*bind_params)
  @stmt.reset!
  @stmt.bind_params(*bind_params)
end

#types ⇒ Object

Returns the types of the columns returned by this result set.



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# File 'lib/sqlite3/resultset.rb', line 75

def types
  @stmt.types
end