DuckDB supports exporting data to Excel .xlsx files via the excel extension. Please note that .xls files are not supported.

To install and load the extension, run:

INSTALL excel; LOAD excel; 

Exporting Excel Sheets

To export a table to an Excel file, use the COPY statement with the FORMAT xlsx option:

COPY tbl TO 'output.xlsx' WITH (FORMAT xlsx); 

The result of a query can also be directly exported to an Excel file:

COPY (SELECT * FROM tbl) TO 'output.xlsx' WITH (FORMAT xlsx); 

Or:

COPY (SELECT * FROM tbl) TO 'output.xlsx'; 

To write the column names as the first row in the Excel file, use the HEADER option:

COPY tbl TO 'output.xlsx' WITH (FORMAT xlsx, HEADER true); 

To name the worksheet in the resulting Excel file, use the SHEET option:

COPY tbl TO 'output.xlsx' WITH (FORMAT xlsx, SHEET 'Sheet1'); 

Type Conversions

Because Excel only really supports storing numbers or strings – the equivalent of VARCHAR and DOUBLE, the following type conversions are automatically applied when writing XLSX files:

• Numeric types are cast to DOUBLE.
• Temporal types (TIMESTAMP, DATE, TIME, etc.) are converted to Excel "serial" numbers, that is the number of days since 1900-01-01 for dates and the fraction of a day for times. These are then styled with a "number format" so that they appear as dates or times when opened in Excel.
• TIMESTAMP_TZ and TIME_TZ are cast to UTC TIMESTAMP and TIME respectively, with the timezone information being lost.
• BOOLEANs are converted to 1 and 0, with a "number format" applied to make them appear as TRUE and FALSE in Excel.
• All other types are cast to VARCHAR and then written as text cells.

But you can of course also explicitly cast columns to a different type before exporting them to Excel:

COPY (SELECT CAST(a AS VARCHAR), b FROM tbl) TO 'output.xlsx' WITH (FORMAT xlsx); 

See Also

DuckDB can also import Excel files. For additional details on Excel support, see the excel extension page.