nbenn opened a new issue, #4820:
URL: https://github.com/apache/arrow-adbc/issues/4820
Executed without a result stream, a statement that changes no rows reports
the row count of the previous `INSERT`, `UPDATE` or `DELETE` in the SQLite
driver. With the driver built from `main` at f1378d6 against SQLite 3.45.1:
```r
library(adbcdrivermanager)
db <- adbc_database_init(adbc_driver("adbc_driver_sqlite"), uri = ":memory:")
con <- adbc_connection_init(db)
execute <- function(sql) {
stmt <- adbc_statement_init(con)
on.exit(adbc_statement_release(stmt))
adbc_statement_set_sql_query(stmt, sql)
adbc_statement_execute_query(stmt)
}
execute("CREATE TABLE t (a INTEGER)")
#> [1] 0
execute("INSERT INTO t VALUES (1), (2), (3)")
#> [1] 3
execute("CREATE TABLE u (b INTEGER)")
#> [1] 3
execute("DROP TABLE u")
#> [1] 3
```
The update path adds `sqlite3_changes()` for every statement without result
columns
([source](https://github.com/apache/arrow-adbc/blob/f1378d664b61ce65f25a54c3b863aa62ea9d2480/c/driver/sqlite/sqlite.cc#L1127-L1129)),
and `sqlite3_changes()` returns the count of the most recent completed
`INSERT`, `UPDATE` or `DELETE`, which other statements leave unchanged
([docs](https://www.sqlite.org/c3ref/changes.html)). It came up in adbi, which
runs statements with a result stream and so gets `-1` from every one of them
(r-dbi/adbi#92); running them without a stream fixes that, but passes these
counts on for DDL.
RSQLite avoids this by taking the difference in `sqlite3_total_changes()`
across the statement
([source](https://github.com/r-dbi/RSQLite/blob/201287ef6db6dce4d5c3e13b1ae6453ea0f570f3/src/SqliteResultImpl.cpp#L123)).
Counting `sqlite3_changes()` only when that total moved does the same here:
```diff
+ const int total_changes = sqlite3_total_changes(conn_);
while (sqlite3_step(stmt_) == SQLITE_ROW) {
output_rows++;
}
- if (sqlite3_column_count(stmt_) == 0) {
+ if (sqlite3_column_count(stmt_) == 0 &&
+ sqlite3_total_changes(conn_) != total_changes) {
changed_rows += sqlite3_changes(conn_);
}
```
With that change, the `CREATE TABLE` and `DROP TABLE` above report 0, as
does a `CREATE INDEX`. The DML counts I checked stay as they were: 3 for an
`INSERT` of 3 rows whose trigger inserts 3 more, 3 for a bound `INSERT` of 3
rows, 0 for an `UPDATE` that matches no rows, and 5 for a `DELETE` of 5. I have
not run the driver's test suite with it. I can open a PR.
This report was drafted with an AI assistant; the code above was run as
shown.
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