Class: SQLite3::ResultSet
- Inherits:
-
Object
- Object
- SQLite3::ResultSet
- 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, client’s should obtain a ResultSet instance via Statement#execute.
Defined Under Namespace
Classes: ArrayWithTypes, ArrayWithTypesAndFields, HashWithTypes
Instance Method Summary collapse
-
#close ⇒ Object
Closes the statement that spawned this result set.
-
#closed? ⇒ Boolean
Queries whether the underlying statement has been closed or not.
-
#columns ⇒ Object
Returns the names of the columns returned by this result set.
-
#each ⇒ Object
Required by the Enumerable mixin.
-
#eof? ⇒ Boolean
Query whether the cursor has reached the end of the result set or not.
-
#initialize(db, stmt, utf_16 = false) ⇒ ResultSet
constructor
Create a new ResultSet attached to the given database, using the given sql text.
-
#next ⇒ Object
Obtain the next row from the cursor.
-
#reset(*bind_params) ⇒ Object
Reset the cursor, so that a result set which has reached end-of-file can be rewound and reiterated.
-
#types ⇒ Object
Returns the types of the columns returned by this result set.
Constructor Details
#initialize(db, stmt, utf_16 = false) ⇒ 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 31 def initialize(db, stmt, utf_16 = false) @db = db @driver = @db.driver @stmt = stmt @utf_16 = utf_16 commence 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 155 def close @stmt.close end |
#closed? ⇒ Boolean
Queries whether the underlying statement has been closed or not.
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# File 'lib/sqlite3/resultset.rb', line 160 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 170 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 146 def each while row=self.next yield row end end |
#eof? ⇒ Boolean
Query whether the cursor has reached the end of the result set or not.
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# File 'lib/sqlite3/resultset.rb', line 70 def eof? @eof end |
#next ⇒ Object
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.
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# File 'lib/sqlite3/resultset.rb', line 87 def next return nil if @eof @stmt.must_be_open! unless @first_row result = @driver.step(@stmt.handle) check result end @first_row = false unless @eof row = [] @driver.data_count(@stmt.handle).times do |column| type = @driver.column_type(@stmt.handle, column) if type == Constants::ColumnType::NULL row << nil elsif type == Constants::ColumnType::BLOB row << @driver.column_blob(@stmt.handle, column) elsif type == Constants::ColumnType::INTEGER row << @driver.column_int64(@stmt.handle, column) elsif type == Constants::ColumnType::FLOAT row << @driver.column_double(@stmt.handle, column) else row << @driver.column_text(@stmt.handle, column, @utf_16) end end if @db.type_translation row = @stmt.types.zip(row).map do |type, value| @db.translator.translate(type, value) end end if @db.results_as_hash new_row = HashWithTypes[ *(@stmt.columns.zip(row).to_a.flatten) ] row.each_with_index { |value,idx| new_row[idx] = value } row = new_row else if row.respond_to?(:fields) row = ArrayWithTypes.new(row) else row = ArrayWithTypesAndFields.new(row) end row.fields = @stmt.columns end row.types = @stmt.types return row end nil 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 60 def reset(*bind_params) @stmt.must_be_open! @stmt.reset!(false) @driver.reset(@stmt.handle) @stmt.bind_params(*bind_params) @eof = false commence end |
#types ⇒ Object
Returns the types of the columns returned by this result set.
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# File 'lib/sqlite3/resultset.rb', line 165 def types @stmt.types end |