Data Import
Detection Steps
The detected types can be individually overridden using the `types` option. This option takes either of two options:  
* A list of type definitions (e.g., `types = ['INTEGER', 'VARCHAR', 'DATE']`). This overrides the types of the columns in-order of occurrence in the CSV file.
* Alternatively, `types` takes a `name` → `type` map which overrides options of individual columns (e.g., `types = {'quarter': 'INTEGER'}`).  
The set of column types that may be specified using the `types` option is not as limited as the types available for the `auto_type_candidates` option: any valid type definition is acceptable to the `types`-option. (To get a valid type definition, use the [`typeof()`](#docs:sql:functions:utility::typeofexpression) function, or use the `column_type` column  of the [`DESCRIBE`](#docs:guides:meta:describe) result.)  
The `sniff_csv()` function's `Column` field returns a struct with column names and types that can be used as a basis for overriding types.