Statement Support

tonic matches statements to action classes before execution. Unsupported actions are rejected before a session opens.

Action Matrix

Action	Postgres	Snowflake	SQLite	MySQL	DuckDB
select	yes	yes	yes	yes	yes
insert	yes	yes	yes	yes	yes
update	yes	yes	yes	yes	yes
delete	yes	yes	yes	yes	yes
merge	yes	yes	no	no	yes
replace	no	no	yes	yes	no
create	yes	yes	yes	yes	yes
copy	no	yes	no	no	no
alter	yes	yes	yes	yes	yes
drop	yes	yes	yes	yes	yes
truncate	yes	yes	no	yes	yes
attach	no	no	yes	no	yes
detach	no	no	yes	no	yes
show	yes	yes	no	yes	yes
describe	no	yes	no	yes	yes
explain	yes	yes	yes	yes	yes
values	yes	yes	yes	yes	yes
call	yes	yes	no	yes	yes
transaction	yes	yes	yes	yes	yes

Backend support means tonic authorizes and forwards that class of statement. The database can still return native syntax or version errors for unsupported server details.

Special Cases

RETURNING does not turn a write into select.

insert into users (email) values ('a@example.com') returning id;

This is kind=query and action=insert.

WITH is inspected for nested data-modifying statements.

with deleted as (delete from jobs where done returning id)
select count(*) from deleted;

This requires both delete and select.

EXPLAIN requires the explain action plus the inner statement action when recognized.

CREATE ... AS SELECT, CREATE ... AS WITH, and CREATE ... AS VALUES require create plus the recognized read action.

Snowflake COPY INTO ... is kind=command and action=copy.

Transaction Action

These map to action=transaction:

• begin
• start transaction
• commit
• rollback
• rollback to ...
• savepoint ...
• release savepoint ...