Hello Igor Zhilin,
Welcome to Tableau !
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You can change the data type for a field either on the Data Source page or in the Data pane.
Sometimes, it might happen, Tableau incorrectly interprets the data type of a field. For example, Tableau might interpret a field that contains dates as an integer data type, rather than a date data type.
You can change the data type for a field that was part of the original data source (as opposed to a calculated field created in Tableau) on the Data Source page.
- Click the data type icon for the field (as shown in the table above).
- Choose a new data type from the drop-down list:
Tip: Be sure to change data types before you create an extract. Otherwise, your data may not be accurate. For example, if a floating-point field in the original data source is interpreted as an integer by Tableau, and you create your extract before you change the field's data type, the resulting floating-point field in Tableau will have some of its precision truncated.
For information on changing data types on the Data Source page, see Data Source Page.
This article from our knowledge base might help you as well: Data Types
Let me know if you need further assistance!
Lénaïc RIÉDINGER, Global Community Engineer Tableau
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