by Roger Carlson
Non-updateable recordsets are a problem that may have many causes and may produce many different error messages. Some of those include:
"This recordset is not updateable."
"Operation must use an updateable query."
"Recordset is not updateable" (seen in the status bar of a query, form, or datasheet view of a table.)
What does this mean? Well, sometimes you can edit data in the Datasheet View of a query to change the information in the underlying table. Other times, you can't. When you can't, the query is "non-updateable". When you try to create a recordset object based on a non-updateable query, the recordset becomes non-updateable.
The Microsoft Office Access Help system has a fairly extensive list that details when queries are updateable and non-updateable. However, this list is difficult to find. It is also in different places depending on the Access version you're using. You would think that typing "updateable recordset" would find the information, but it doesn't.
In Access 2003, you can find this information if you type: "When can I update data from a query?"
In Access 2007, type: "edit data in a query"
I thought it would be useful to list the information in a place that's a little easier to find.
When Recordsets Are Always Updateable
A recordset is always updateable when:
- It is based on a single table.
- It is based on a query based on a single table.
- It is based on a query based on tables with a one-to-one relationship.
A recordset is never updateable when:
- It is based on a Crosstab query.
- It is based on a Union Query.
- It is an Aggregate Query that calculates a sum, average, count or other type of total on the values in a field.
- It is an Update Query that references a field in the Update To row from either a crosstab query, select query, or subquery that contains totals or aggregate functions
Note: By using a domain aggregate function in the Update To row of an update query, you can reference fields from either a crosstab query, select query, or subquery that contains totals or aggregate functions.
- It is based on a Query that includes a linked ODBC table with no unique index.
- The database was opened as read-only or is located on a read-only drive.
- It is a SQL pass-through query.
- It is a query whose UniqueValues property is set to Yes. (That is, it is a query with a DISTINCT predicate.)
- Cartesian Joins (that is, a query that includes more than one table or query, and the tables or queries aren't joined by a join line in Design view.)
- Query based on three or more tables in which there is a many-to-one-to-many relationship.
Note: Though you can't update the data in the query directly, you can update the data in a form or data access page based on the query if the form's RecordsetType property is set to Dynaset (Inconsistent Updates).
- Calculated fields. Even if the query itself is updateable, if a column in a query is based on a formula, the field cannot be updated. However, if the other fields in the formula are updated, the calculated field will automatically update.
Some queries, especially those involved in a Join, will not be updateable under some conditions, but will be under others. In other queries, even if the query itself is updateable, some of the fields will not be. The following are cases of query problems and their corresponding solutions.
1. Query based on a Join of tables with no Relationship.
- Problem: If a query is based on two or more tables that DO NOT have a relationship established (with Referential Integrity enabled), the query will be non-updateable.
- Solution: Create a Primary Key or Unique Index on ALL of the fields used in the Join on the "one-side" table. To be clear, this means ONE primary key or unique index based on all of the fields, not separate indexes on each field.
2. Join field from the "one" side
- Problem: If you have a 1:M relationship created between two tables, you cannot change the primary key field (used in the Join) of the table on the "one" side of the relationship.
- Solution: Enable cascading updates between the two tables.
- Problem: In a query based on a 1:M relationship, you can create a new record and fill in the fields that come from the "one" side table, but if the join field from the "many" side table is not visible in the query (that is, the foreign key), you cannot add data to the "many" side fields.
- Solution: Add the join field from the "many" side table (ie, foreign key) to your query to allow adding new records.
- Problem: When adding a new record, if you try to type into the "one" side fields, you will be attempting to create a new record. Even if you use the same primary key values, it will give you an error.
- Solution: Add a value to the "many" side join field (foreign key) that matches the "one" side join field (primary key) of an already existing record. The "one" side values will simply appear.
- Problem: If you are currently editing fields from the "one" side of the relationship, you cannot change the "many" side join field (foreign key).
- Solution: Save the record; then you'll be able to make changes to the "many" side join field.
- Problem: This is different than #5 under Never Updateable. In this case, the primary key of the linked ODBC table exists, but is not added to the query.
- Solution: Select all primary key fields of ODBC tables to allow inserts into them.
- Problem: Query (or underlying table) for which Update Data permission isn't granted.
- Solution: To modify data, permissions must be assigned.
- Problem: Query (or underlying table) for which Delete Data permission isn't granted
- Solution: To delete data, permissions must be assigned.
The causes of non-updateable recordsets are many and varied. Some have solutions and others don't. Hopefully, this list will help you know the difference.
Addendum (January 28, 2010):
This is in response to a comment below. I thought it was important enough to add to the main article.
Linked Excel Sheets Not Updateable
The question is why are my linked sheets from an Excel Workbook non-updateable? The answer is not technical but legal. Several years ago, Microsoft lost a patent infringement lawsuit that involved the ability to update records in Excel from Access. The upshot is that in Access 2003 and later versions, by design, you can no longer update data in Excel spreadsheets.