| name | gaussdb-adaptation |
| description | Use this skill when porting SQL Server or vanilla PostgreSQL code to Huawei GaussDB (Kernel 505.x / openGauss-based). TRIGGER when source code or SQL contains any of — `Microsoft.Data.SqlClient`, `SqlBulkCopy`, `NEXT VALUE FOR`, `ON COMMIT DROP`, `CREATE TEMPORARY SEQUENCE`, `dbo.`, `NVARCHAR`, `ISNULL(`, `GETDATE()`, `OPTION (MAXDOP`, `TOP N`, `@@IDENTITY`, `WITH (NOLOCK)`, `[bracketed]` identifiers, `#tempTable`; OR csproj references `DotNetCore.GaussDB`, `DotNetCore.EntityFrameworkCore.GaussDB`, `HuaweiCloud.Driver.GaussDB`, `HuaweiCloud.EntityFrameworkCore.GaussDB`, `Npgsql.EntityFrameworkCore.PostgreSQL` alongside a GaussDB target; OR appsettings has `Persistence.Provider=GaussDb`; OR user mentions GaussDB / openGauss / 高斯数据库 / SHA256 SASL / `password_encryption_type` / apuração GaussDB migration. |
GaussDB Adaptation
Overview
GaussDB (Huawei, kernel 505.x / openGauss-based) speaks a PG-compatible but not identical dialect. Code that compiles and runs against SQL Server — or even vanilla PostgreSQL — often fails on GaussDB in three categories:
- SQL dialect — e.g.
CREATE TEMPORARY SEQUENCE and ON COMMIT DROP are rejected at runtime
- Driver / authentication —
DotNetCore.GaussDB fails SHA256-only servers with a cryptic protocol error; Huawei's own HuaweiCloud.Driver.GaussDB works but uses a different namespace
- Bulk loading —
SqlBulkCopy has no drop-in replacement; the correct pattern is BeginBinaryImport + COPY ... FROM STDIN BINARY
The skill encodes landmines discovered on a real production port, with concrete before/after pairs.
Quick Start
For any adaptation task, run this 4-step flow:
- Audit — run
scripts/sql_dialect_audit.py <project-root> to locate all anti-patterns, or grep for them manually (trigger list above)
- Map SQL dialect — rewrite hits using references/sql-dialect-map.md
- Verify driver + auth — confirm csproj packages +
using match the server's password_encryption_type per references/connectivity-and-auth.md
- Validate end-to-end — run
scripts/gaussdb_connect_probe.cs against the target GaussDB to confirm connection + BINARY COPY + nextval all work; then build the real project
Workflow Decision Tree
| Task shape | Route |
|---|
| One-off SQL rewrite (single query / proc from T-SQL or vanilla PG) | Read sql-dialect-map.md, rewrite category-by-category |
App porting (.NET project with Microsoft.Data.SqlClient / Npgsql) | Read connectivity-and-auth.md for driver choice, bulk-load-patterns.md for SqlBulkCopy replacement, then dialect-map for any embedded SQL |
| Reviewing new code meant for GaussDB | Scan with sql_dialect_audit.py; cross-reference common-pitfalls.md for subtle issues (copy-paste namespace leaks, wrong package versions, raw-string typos) |
Driver errors at runtime (Invalid username/password, AuthenticationRequest protocol error) | Jump directly to connectivity-and-auth.md driver decision tree |
Core Rules
- Never use in a GaussDB target:
ON COMMIT DROP, CREATE TEMPORARY SEQUENCE, TOP N, OPTION (...), WITH (NOLOCK), dbo. schema prefix, IDENTITY(…) column type, @@IDENTITY, #tempTable, [bracketed] identifiers, NVARCHAR, ISNULL(, GETDATE(), DATEADD(, NEWID(), LEN(, SET XACT_ABORT, SET NOCOUNT, BEGIN TRY … END CATCH, EXEC proc @p=v, DECLARE @var, MERGE ... OUTPUT, INSERT ... OUTPUT
- Always check
SHOW password_encryption_type on the target server before choosing a driver:
0 or 1 → DotNetCore.GaussDB 9.0.0 (MD5 path works, net9.0 OK)2 (SHA256-only, GaussDB 505+ default) → HuaweiCloud.Driver.GaussDB 0.1.0 (only one with working SHA256 SASL for this server family)
- Replace
SqlBulkCopy.WriteToServerAsync(tbl) with using var w = conn.BeginBinaryImport($"""COPY "{t}" FROM STDIN BINARY"""); foreach row → w.StartRow(); w.Write(v, GaussDBDbType.X); await w.CompleteAsync(ct);
- Reserve id blocks via
SELECT nextval('seq') - N + 1 in a single roundtrip; never IDENTITY columns in new tables
- Temp tables:
CREATE TEMP TABLE x (...) ON COMMIT DELETE ROWS; — preceded by DROP TABLE IF EXISTS x; for reentrant batches
- Temp sequences: don't create them. Use a permanent sequence with
DROP SEQUENCE IF EXISTS x; CREATE SEQUENCE x ...; bracket, and a final DROP SEQUENCE IF EXISTS x; at script end
Default Deliverables
When invoked, produce:
- A hit list from the dialect audit (file:line → category → suggested replacement)
- Rewritten code for each hit, preserving business semantics
- A driver/auth verdict (is current csproj compatible with target server?) with upgrade steps if not
- An e2e verification command the user can run (usually the bundled probe script, parameterized with their DSN)
Sanitization Rules
- Never emit real connection strings, passwords, hostnames, or customer identifiers into checked-in files. Use placeholders:
<host>, <port>, <user>, <pwd>, <database>
- When demonstrating a connection in a generated file, read DSN from environment (
GAUSSDB_DSN) rather than hard-coding
- Treat private NuGet package names, internal namespaces, and business domain terms in examples as illustrative; genericize when documenting
Script Use
scripts/sql_dialect_audit.py <dir> — stdlib-only Python, walks a tree and reports every anti-pattern by file:line → category. Use to quickly inventory an unfamiliar codebase before planning a port.scripts/gaussdb_connect_probe.cs — single-file .NET 9 probe. GAUSSDB_DSN=... dotnet run to verify a driver + server combo. Exercises connect, encryption check, BINARY COPY, nextval, commit. Use to confirm the environment before touching business code.
Reference Use
Pull in only when the task demands:
