DB_Column.parse

parsetypeformaton_problems

Group: Conversions

Documentation

Parses a text column into values. In the Database backends, the default formatting settings of the particular database are used. In the in-memory backend, the default parser options only parse values where the process is reversible (e.g., 0123 would not be converted to an integer as there is a leading 0). However, settings in the Data_Formatter can control this.

Arguments

• type: The type to parse the column to. Defaults to Auto meaning that the type will be inferred from the data. In the Database backends, Auto is not supported, so a specific type must be selected.
• format: The formatting settings to use when parsing the column. For Date, Time_Of_Day and Date_Time, a Java date time style can be used. For Boolean, it should be two values that represent true and false, separated by a |. Alternatively, a Data_Formatter can be passed to provide complete customisation of the formatting. If "" is provided, the default formatting settings of the backend will be used. "" is currently the only setting accepted by the Database backends.
• on_problems: Specifies how to handle if a problem occurs, raising as a warning by default.

Errors

• If the column is not a text column, an Invalid_Value_Type error is raised.
• If some values in the column did not match the expected datatype format, an Invalid_Format problem is reported. The problematic cells are replaced with Nothing.
• If custom formatting settings were provided, but the database backend does not support customization, an Unsupported_Database_Operation error is reported.