Item 2: a tag's optional `write` block picks the statement the driver builds from its own
catalog-validated identifiers (no authored SQL; values always bound):
- Update (default, unchanged back-compat UPDATE ... WHERE key; 0 rows = BadNoData)
- Insert (key+value[+stamp]; append for a WideRow topByTimestamp tag)
- Upsert: SQL Server MERGE WITH (HOLDLOCK), PostgreSQL INSERT ... ON CONFLICT, MySQL
ON DUPLICATE KEY UPDATE (1-or-2 rows), Oracle MERGE from DUAL
- Procedure: named stored procedure resolved against the routine catalog by the catalog gate
(INFORMATION_SCHEMA.ROUTINES / ALL_PROCEDURES), value/key/timestamp params by name (MySQL positional)
- stampTimestamp sets the tag's timestamp column to the write time (UTC)
Odbc serves Update/Insert only (shared SqlWriteSupport table). Constraint failures map to
BadEntryExists (unique) / BadOutOfRange (other integrity, data exception); everything else,
permission denied included, stays BadCommunicationError. WriteIdempotent stays false.
The parser refuses malformed blocks (strict keys/enums/param charset); DraftValidator emits
blocking SqlWriteBlockInvalid / SqlWriteModeUnsupported from the driver's own parse; the AdminUI
editor surfaces the same message.
Items 1 + 4 (docs/drivers/Sql.md): ODBC stays the ANSI SQL:2008 profile (native providers for
SQL Server/MySQL, DB2 unsupported) with an ops note on driver manager + vendor driver on every
Odbc and AdminUI host; read-only drivers require a SELECT-only login, writable drivers a login
limited to their write targets.
Tests: SqlWriteModeTests (parse, every dialect's SQL, gate, status map, SQLite end-to-end),
DraftValidatorSqlWriteBlockTests, AdminUI round-trip; live SqlWriteModesLiveTests on SQL Server,
PostgreSQL, MySQL, Oracle (seeds gain write_targets + set_target) and an Odbc write leg.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
allowWrites is no longer inert: SqlDriver implements IWritable, default off.
- Gates (outermost first): node Writable + WriteOperate (server), driver
allowWrites, the tag's own TagConfig "writable": true (strict JSON boolean;
anything else refuses the tag, and the deploy gate says why), and a model that
names exactly one row — KeyValue, or WideRow by where-pair. topByTimestamp and
Query are BadNotWritable.
- SqlWritePlanner: the only statement a write can become is
UPDATE <table> SET <value col> = @v WHERE <key col> = @k, built from the
catalog-gate-canonical identifiers (dialect-quoted) with value and key bound;
value-before-key marker order so positional ODBC binds correctly. No authored
write SQL, INSERT, UPSERT or procedure.
- Executed in a transaction that commits only when exactly one row was touched:
0 rows -> BadNoData (never inserts), >1 -> rolled back, BadConfigurationError,
unknown count -> rolled back, BadNotSupported. Bounded by operationTimeout;
provider errors -> BadCommunicationError; health untouched.
- Discovery advertises Operate only where a write could succeed.
- AdminUI: driver form's Allow writes switch is live; tag editor gains a
per-tag write switch; model validates writable strictly (parity corpus).
- Factory no longer warns "allowWrites ignored"; it logs whether writes are on.
- Tests: SqlWriteTests (planner SQL/bind order/injection/coercion, every gate,
readback, absent key, two-row rollback, gate-rejected tag, discovery);
MySqlReadTests write legs against InnoDB (keyed row only, two-row rollback,
server-side grant refusal, default-off). Seed adds a setpoints table and the
one UPDATE grant.
(lmxopcua#753)
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
SqlProvider.Odbc is now constructed; every enum member is a working backend.
- OdbcDialect: System.Data.Odbc 10.0.14 (no vulnerable packages), ANSI double-
quote quoting, positional `?` markers, INFORMATION_SCHEMA catalog (system
schemas of the common backends excluded by name — the live gate caught
psqlODBC listing pg_catalog), FETCH FIRST n ROWS ONLY limits, a conservative
1000-parameter chunk. Positional binding is safe because every caller adds
parameters in marker order (planner IN list, catalog schema-then-table).
- Named queries on a positional provider are checked by `?` count against the
declared params (literals/comments ignored), since there is no name to match.
- Supported backends are those whose SQL accepts that profile (PostgreSQL via
psqlODBC proven, Snowflake-like); SQL Server/MySQL/DB2 should use their native
provider. The host needs the ODBC driver manager + vendor driver.
- Reserved-provider controls in factory/probe/browser tests now use an
undeclared ordinal (99); the AdminUI form offers Odbc and a test pins the
dropdown theory to SqlDialects.Supported.
- Tests: OdbcDialectTests (unit, any host). OdbcReadTests + Docker/odbc/
run-odbc-gate.sh run the built suite in a throwaway Linux SDK container with
unixODBC + psqlODBC against a throwaway seeded PostgreSQL: KV IN-list
positional binding, where-pair, topByTimestamp via FETCH FIRST, a two-
parameter named query, and the browse walk. macOS has no vendor ODBC driver,
so there the suite skips.
(lmxopcua#753)
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
SqlProvider.MySql is now a constructed backend instead of a reserved name.
- MySqlDialect (Driver.Sql.Dialect): MySqlConnector 2.6.2 (MIT, fully managed,
no vulnerable packages), backtick quoting with MySQL's 64-char / no-trailing-
space rules, information_schema catalog SQL with the database as the schema
(system databases excluded, aliases pinned), trailing LIMIT, a type map that
also reads the reader-side spellings (INT UNSIGNED -> UInt32, BOOL -> Boolean).
- SqlDialects: the one provider -> dialect map. The factory, the Test Connect
probe and the browse picker each carried their own switch (and drifted once);
they now all read this, and their refusals list the supported/reserved sets
from it.
- AdminUI driver form offers MySql.
- Tests: MySqlDialectTests (golden quoting/catalog/type map/planner SQL); the
provider-gate tests in factory, probe, browser and form now treat MySql as
supported and Odbc as the reserved control. MySqlReadTests + Docker/mysql
(throwaway mysql:8.4, SELECT-only login): liveness, KV/wide-row/topByTimestamp,
INT keys vs authored text, case folding against case-sensitive table names,
catalog rejection, browse walk, factory+probe, named query with a bound
parameter, and a writing stored function whose effect the rolled-back
transaction discards.
(lmxopcua#753)
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Two disposable docker fixtures (postgres:17-alpine on 15432, gvenzl/oracle-free:
23-slim on 11521) shaped like the existing mssql one — project label, distinct
container name, healthcheck, one-shot seed service — plus a live suite per
provider, gated on SQL_PG_* / SQL_ORACLE_* and skipping clean offline.
Each suite covers what a DIALECT can get wrong, rather than re-running the
provider-agnostic read semantics already pinned against SQL Server and SQLite:
liveness + catalog load, a KeyValue read, the provider's own row-limit syntax via
topByTimestamp (LIMIT 1 / FETCH FIRST 1 ROWS ONLY, where T-SQL emits TOP 1),
identifier case-folding through the design §8.1 catalog gate, and the AdminUI
browse walk driven through SqlDriverBrowser.
Two seed decisions are load-bearing rather than scaffolding:
- The Postgres schema is owned by a role the suite is NOT; the connecting login
holds USAGE + SELECT only. That is the exact provisioning PostgresDialect's
ListSchemasSql exists for (information_schema.schemata lists only schemas the
role OWNS, so a granted-not-owning poller would see none and every tag would be
rejected). A fixture that owned its own schema would pass either way.
- Every identifier in both seeds is created UNQUOTED, so the catalogs hold
lower-case (Postgres) and UPPER-case (Oracle) spellings. The case-folding legs
author the opposite case and pin SqlCatalog.TryMatch's REAL contract — exact
ordinal first, then a UNIQUE case-insensitive match whose catalog spelling is
substituted — which on both providers is what makes mixed-case authoring work
at all, since both dialects emit case-sensitive double-quoted identifiers.
Connection strings are composed through dialect.Factory.CreateConnectionString-
Builder() and the abstract DbConnectionStringBuilder indexer, so the csproj keeps
its no-direct-provider-reference discipline; every key used was verified accepted
through that indexer. The csproj gains only Driver.Sql.Browser, for the browse leg.
Live-run evidence (local OrbStack, both images arm64): Postgres 5/5 green;
Oracle 6/6 green after the ORA-01745 dialect fix this suite found. Offline the
whole project is 33 skipped / 0 failed.
Adds the frozen-peer / BadTimeout gate for the Sql driver — the single
highest-value integration test. Mirrors the S7 R2-01 blackhole gate:
docker pause a DEDICATED mssql mid-poll, assert the next read surfaces
BadTimeout within the client-side operationTimeout (≈3s) and well below
the server-side CommandTimeout backstop (30s), the driver degrades
(Degraded + host Stopped), and docker unpause recovers to Healthy/Running.
- Docker/docker-compose.yml: disposable `otopcua-sql-blackhole` mssql on
:14333 (never the shared :14330 ConfigDb server) + one-shot seed.
- Docker/seed.sql: the two sample tables.
- SqlBlackholeTimeoutTests.cs: env-gated (SQL_BLACKHOLE_ENDPOINT); pauses
ONLY the hard-coded container name; skips loudly if the endpoint is the
shared port 14330; bounds its own wait so a wedged impl fails, not hangs.
Offline: clean skip (no socket, no docker shell-out).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty