Merge tables

Fusion Tables enables combining data from multiple sources and people -- that is, merging different tables. For example, you could merge eight different tables with various survey results for US hospitals to create one useful hospital information resource. Or you might want to combine a table with county boundaries with a table of county census data to show population trends graphically on a map. This unique ability to combine or fuse data that may be owned by different people is why we're called "Fusion" Tables.

You can tell a table is merged when columns have different background colors. Each color reflects a different source table. Check File > About to see the tables that have been merged into this one. 

The merge function is also quite useful to create custom intensity maps or extract subsets of larger data.

Merged tables are just a virtual combination of the tables that make them up. Changes in the original tables' data will be seen in the merged table.

To merge two tables, you need to identify a column in each table to use for matching up values. (For SQL fans, this is a join on primary key.) The merge will use an exact case-insensitive text match.  Usually it's best if the table you start from has only unique values in the column you'll use to merge. 

Value Will match Will not match
California CALIFORNIA CA
SANTA CLARA COUNTY, CA Santa Clara County, CA County of Santa Clara
Barack Obama barack obama Obama, Barack

To merge tables:

  1. Choose File > Merge. (If inactive, sign in first.) 
  2. Select the table to merge with from your Google Drive list, or paste in the URL of a table. Click Next
  3. For both tables, select a column from the Match columns dropdown menu.
    Choose columns that contain the same text, examples of which are previewed here.
    Tip: This isn't a preview of how the values will match up - these samples may be from different parts of the tables.
  4. Review the columns for the new table, and uncheck any you don't wish to include.
  5. Click "Create merged table."

When starting from a merged table, you'll have the option to merge the new columns into the existing table.

Limitations of merged tables

These features are not available on merged tables:

  • File > Make a copy
    • Use File > Download and then import the .csv to a new table.
  • File > Import new rows
    • New rows will appear if matching rows are added to the base tables.
  • Edit > Delete all rows
    • Rows will go away if they no longer match from the base tables.
  • File > Create view
  • Edit > Add column
  • Edit > Add formula column
  • Deleting a column

Adding new columns to merged tables

New columns added to base tables will not be available to the merged tables. To include new columns, the merge of the base tables must be created again.

After merging two or more tables, you cannot use Edit > Add column to add additional columns to the merged table. You can only merge more columns in. These new columns must come from a table that isn't already part of the merge.