Although chained mode implicitly begins transactions with data retrieval or modification statements, you can nest transactions only by explicitly using begin transaction statements. Once the first transaction implicitly begins, further data retrieval or modification statements no longer begin transactions until after the first transaction commits or aborts. For example, in the following query, the first commit transaction commits all changes in chained mode; the second commit is unnecessary:
insert into publishers values ("9907", null, null, null) insert into publishers values ("9908", null, null, null) commit transaction commit transaction
In chained mode, a data retrieval or modification statement begins a transaction whether or not it executes successfully. Even a select that does not access a table begins a transaction.
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