1. A computer-implemented method comprising: receiving natural language input at a computing device; processing the natural language input in a first conditional random field to obtain a first output from the first conditional random field, the processing in the first conditional random field comprising extracting at least a first entity and a second entity from the natural language input, labeling the first entity as a column value, and labeling the second entity as a column name, the first output comprising a column value label associated with the first entity and a column name label associated with the second entity; processing the natural language input and the first output in a second conditional random field to obtain a second output from the second conditional random field, the processing in the second conditional random field comprising identifying at least one relationship between the first entity and the second entity, the second output comprising information that represents the at least one relationship.