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.
[R] | columns | An array of the column names for this result set (may be empty) |
[R] | types | An array of the column types for this result set (may be empty) |
Module SQLite::ResultSet::TypesContainer
- Enumerable
Create a new ResultSet attached to the given database, using the given sql text.
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# File lib/sqlite/resultset.rb, line 62 62: def initialize( db, sql ) 63: @db = db 64: @sql = sql 65: commence 66: end
Close the result set. Attempting to perform any operation (including close) on a closed result set will have undefined results.
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# File lib/sqlite/resultset.rb, line 90 90: def close 91: API.finalize( @vm ) 92: end
Required by the Enumerable mixin. Provides an internal iterator over the rows of the result set.
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# File lib/sqlite/resultset.rb, line 160 160: def each 161: while row=self.next 162: yield row 163: end 164: end
Query whether the cursor has reached the end of the result set or not.
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# File lib/sqlite/resultset.rb, line 104 104: def eof? 105: @eof 106: 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.
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# File lib/sqlite/resultset.rb, line 121 121: def next 122: return nil if @eof 123: 124: if @current_row 125: result, @current_row = @current_row, nil 126: else 127: result = API.step( @vm ) 128: check_eof( result ) 129: end 130: 131: unless @eof 132: row = result[:row] 133: 134: if @db.type_translation 135: row = @types.zip( row ).map do |type, value| 136: @db.translator.translate( type, value ) 137: end 138: end 139: 140: if @db.results_as_hash 141: new_row = Hash[ *( @columns.zip( row ).flatten ) ] 142: row.each_with_index { |value,idx| new_row[idx] = value } 143: row = new_row 144: else 145: row.extend FieldsContainer unless row.respond_to?(:fields) 146: row.fields = @columns 147: end 148: 149: row.extend TypesContainer 150: row.types = @types 151: 152: return row 153: end 154: 155: nil 156: end
Reset the cursor, so that a result set which has reached end-of-file can be rewound and reiterated. Note: this uses an experimental API, which is subject to change. Use at your own risk.
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# File lib/sqlite/resultset.rb, line 97 97: def reset 98: API.finalize( @vm ) 99: commence 100: @eof = false 101: end