This is a known limitation with Excel worksheets.

This is a known limitation with Excel worksheets.

When you connect to Excel, the driver automatically scans the first eight rows in a column and applies the data type used in a majority of those rows to all rows in the column. Any rows that do not meet the majority data type display as null values.

Solution 1: Reformat worksheet column and values as text.

1. Open the worksheet in Excel.

2. Format the column that contains mixed data types as Text.

3. You can now connect to this spreadsheet from Toad without any null values displayed.

Solution 2: Create an ODBC connection.

You can force the ODBC driver to read all rows as Text to avoid null values; however, this can result in issues if you attempt to insert data.

1. Open the Create New Connection window and select ODBC from the Group list.

2. Complete the fields as described in Create ODBC Connections.

3. Enter "IMEX=1", in quotations, in the ExtraParameters field.

4. Click Connect.

The exclamation point character has a special meaning in Excel. If a column name contains an exclamation point, it is internally converted to a dollar sign ($) character.

Tables cannot be altered when the Excel connection is Read-Only.

Solution: Deselect Read-Only Connection in the Connection Properties dialog.

Excel is a spreadsheet, and does not support primary and foreign keys so these tabs are always blank.

The Excel ODBC driver does not support this functionality.

The worksheet you are querying does not have named ranges (regions) defined.

Solution:

You can query the worksheet from the Editor by entering a dollar sign ($) followed by a cell range to limit the results similar to the following statement: 

Select * from (MyWorksheet$A1:C10)

You can also query the entire worksheet by entering a dollar sign ($) after the worksheet name. However, this may also return the worksheet's empty rows and columns.

The Excel file does not have named ranges (regions) defined. If you click OK to close the message, the new connection is created, but no user tables display in Object Explorer. (System tables are displayed, if you selected to show these.)

Solution 1: In the Excel file, create named ranges.

Solution 2: Ask Toad to automatically create named ranges.

1. Disconnect from the file.
2. In Navigation Manager, right-click the file and select Properties | Advanced.

3. Select Automatically create ranges.

   The next time you connect, Toad automatically creates named ranges, which are then displayed as tables.

Create Excel Connections

The underlying data format cannot differentiate between an empty string and null data, so a query with a search condition that contains an empty string does not match any empty strings in the table. This occurs because the empty string is treated as a null value, and a null value never matches anything, not even another null value.

The Excel ODBC driver does not support this functionality. While it is possible to update values, DELETE statements do not remove a row from a table. Basically, you can only insert data in a table.

This error occurs if you have more than one named range (region) in the same worksheet, and the named ranges are not separated by blank rows.

Solution 1: You must add blank rows between named ranges. Add as many blank rows as you have new records to insert.

Solution 2: Include only one named range in each worksheet.

When exporting to Excel, be aware that Excel worksheets have limits for maximum number of rows and columns supported.

See Microsoft Excel specifications and limits for more information.

The Toad document window cannot display all Excel menus.

Solution:

Right-click the Excel toolbar and add the equivalent toolbar for the missing menu or functionality.

Toad document windows support one Excel instance at a time. Opening more than one Excel file disables the Excel toolbars for the additional files.

Solution:

Open only one Excel file at a time.