In SQL in Excel or SQL in Access,update statements are used to update multiple data sets in batches.
If table A and table B have the same structure, as follows:ID field, data field 1, data field 2, data field N
Where, the ID field primary key (set index in access). The data field has N columns,N is greater than 2 and less than 20
Suppose that table A now has 100,000 entries;There are 50,000 pieces of data in table B, 10,000 of which are new ID fields that table A does not have, 20,000 pieces of which are existing in table A but at least one corresponding data field has changed, and 20,000 pieces of which are existing in table A but all the data fields have not changed at all.