class SQLite3::ResultSet
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
.
Public Class Methods
Create a new ResultSet
attached to the given database, using the given sql text.
# File lib/sqlite3/resultset.rb, line 49 def initialize db, stmt @db = db @stmt = stmt end
Public Instance Methods
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.
# File lib/sqlite3/resultset.rb, line 115 def close @stmt.close end
Queries whether the underlying statement has been closed or not.
# File lib/sqlite3/resultset.rb, line 120 def closed? @stmt.closed? end
Returns the names of the columns returned by this result set.
# File lib/sqlite3/resultset.rb, line 131 def columns must_be_open! @stmt.columns end
Required by the Enumerable mixin. Provides an internal iterator over the rows of the result set.
# File lib/sqlite3/resultset.rb, line 97 def each must_be_open! while node = self.next yield node end end
Provides an internal iterator over the rows of the result set where each row is yielded as a hash.
# File lib/sqlite3/resultset.rb, line 106 def each_hash while node = next_hash yield node end end
Query whether the cursor has reached the end of the result set or not.
# File lib/sqlite3/resultset.rb, line 64 def eof? @stmt.done? end
Obtain the next row from the cursor. If there are no more rows to be had, this will return nil
. If type translation is active on the corresponding database, the values in the row will be translated according to their types.
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.
# File lib/sqlite3/resultset.rb, line 81 def next must_be_open! if @db.results_as_hash return next_hash end row = @stmt.step return nil if @stmt.done? row = ArrayWithTypesAndFields.new(row) row.fields = @stmt.columns row.types = @stmt.types row end
Return the next row as a hash
# File lib/sqlite3/resultset.rb, line 137 def next_hash must_be_open! row = @stmt.step return nil if @stmt.done? # FIXME: this can be switched to a regular hash in 2.0 row = HashWithTypesAndFields[*@stmt.columns.zip(row).flatten] # FIXME: these methods are deprecated for version 2.0, so we can remove # this code in 2.0 row.fields = @stmt.columns row.types = @stmt.types row end
Reset the cursor, so that a result set which has reached end-of-file can be rewound and reiterated.
# File lib/sqlite3/resultset.rb, line 56 def reset( *bind_params ) must_be_open! @stmt.reset! @stmt.bind_params( *bind_params ) @eof = false end
Returns the types of the columns returned by this result set.
# File lib/sqlite3/resultset.rb, line 125 def types must_be_open! @stmt.types end
Private Instance Methods
# File lib/sqlite3/resultset.rb, line 154 def must_be_open! raise Exception, "#{self.class} is closed!" if closed? end