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Change Column Data Type

While transforming your data, you may need to change the data type of one or more columns. For example, data of String type may be the easiest to manipulate. Since there are no mismatched values for String data type, you may wish to change a column's data type to this baseline type.

  • Data types that you see in the Transformer page represent types that are understood by the product.

  • When data is imported from a separate datastore, Designer Cloud Powered by Trifacta Enterprise Edition may apply internal data types to the data. These types may differ from the original data typing in the source. As needed, the inferring of data types can be disabled at the file, connection, or global level. For more information, see Disable Type Inference.

  • When data is published from the product to a separate datastore, these types may be mapped to different data types in the target. For more information, see Type Conversions.

Tip

You can use the Change Column Type transformation to override the data type inferred for a column. However, if a new transformation step is added, the column data type is re-inferred, which may override your specific typing. You should consider applying Change Column Type transformations as late as possible in your recipes.

For more information on the available data types, see Supported Data Types.

Change Type

You can change a column's data type in one of the following ways:

Change from Column Menus

You can change the data type for individual columns through the following column menus:

  1. To the left of the column name, you can click the icon and select a new data type from the list.

    ChangeColumnDataType-DataTypeMenu.png

    Figure: Column Data Type Menu

  2. To the right of the column name, you can click the caret to open the column menu. Select Change Type and make a selection from the sub-menu.

Tip

Both of the above methods become individual steps in your recipe.

Change Data Type for Multiple Columns

If you must change the data type for multiple columns to a single data type, you can use a transformation like the following, which changes the columns LastName, FirstName, and Address to String data type.

Transformation Name

Change column type

Parameter: Column 1

LastName

Parameter: Column 2

FirstName

Parameter: Column 3

Address

Parameter: New Type

String

Note

When specifying a data type by name, you must use the internal value for the data type. The value in the column menu is the display name for the type.

For more information, see Valid Data Type Strings.

Change Datetime Data Type

If you are changing a column's data type to Datetime, you must also select a format string to apply to the column.

Via column menus

You can apply a Datetime data type through the column menus. When you choose the Datetime data type, you must apply a format for your Datetime values. For more information, see Choose Datetime Format Dialog.

Via Transform Builder

In the Transformer Builder, you can apply a specific transformation to format one or more columns to Datetime data type, using a specific format.

Tip

You can use the following transformation to change the format of a Datetime column.

This transformation looks like the following:

Transformation Name

Change column type

Parameter: Columns

Multiple

Parameter: Column 1

myDate

Parameter: New Type

Date/Time

Parameter: Date/time Type

month*dd*yyyy*hh:MMaX

For more information, see Datetime Data Type.

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