I am trying to join my csv data to TIGER census block group shapefiles. Every time I bring the table into QGIS it changes the string for the GEOID into a number so the join comes up null. My csv only has the block group ID to make the link, no address info or coordinates.


1 Answer 1


Several ways to define a field type

  1. Before importing the CSV, create a csvt file that defines the field types

After importing the CSV, change the field type:

  1. In QGIS 2.8 or later, Use the Refactor Field algorithm (found in the Processing Toolbox) to change the field type

  2. Use the Field Calculator to create a new field of the desired data type. For the field value, use the name of the original field in double quotation marks, eg if the field is called GEOID, use this expression:


    Note that two fields cannot have the same name, so the new field must have a different name than the original field. If you need the new field to have the same name as the original, create a new field with a different name, delete the original field, then create another new field with the original name.

  3. In QGIS 2.18 or older, use the Table Manager plugin to change the field type

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    – csk
    Jul 12, 2018 at 16:00

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