I need to compare a numeric field in access to a custom field in quickbooks, creating a custom field in quickbooks seems to default to text and in order for the query to work the custom field must be numeric in quickbooks. Opening a linked table from Access wont let me change the data type and I found no setting in quickbooks that lets me change the datatype of the custom field to numeric.

I suppose I could move some data in access to a table with a field that is text instead of numeric...

Any other ideas?

First of all, we can't change the format type of a column. The format type of a field is predetermined by QuickBooks, not us, and all custom fields are strings. You can however change the type of a returned column (providing there's valid data), for example:

SELECT TxnID, {fn CONVERT(InvoiceLineSeqNo, SQL_INTEGER)} as LineNo,
InvoiceLineServiceDate, InvoiceLineItemRefFullName, InvoiceLineDesc,
InvoiceLineQuantity, InvoiceLineRate, InvoiceLineAmount FROM InvoiceLine

CONVERT(value_exp, data_type) - The function returns the value specified by value_exp converted to the specified data_type, where data_type is one of the following keywords:

SQL_BIGINT, SQL_BINARY, SQL_BIT, SQL_CHAR, SQL_DATE, SQL_DECIMAL, SQL_DOUBLE, SQL_FLOAT, SQL_INTEGER, SQL_LONGVARBINARY, SQL_LONGVARCHAR, SQL_NUMERIC, SQL_REAL, SQL_SMALLINT, SQL_TIME, SQL_TIMESTAMP, SQL_TINYINT, SQL_TYPE_DATE, SQL_TYPE_TIME, SQL_TYPE_TIMESTAMP, SQL_VARBINARY, SQL_VARCHAR