### What problem does this PR solve?
Close#12768.
This PR adds OceanBase support to RAGFlow’s Text-to-SQL (ExeSQL)
component.
OceanBase is integrated via MySQL compatibility mode, and the UI
`db_type` options are updated accordingly.
### Type of change
- [ ] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):
### Changes
**Backend**
- Add `oceanbase` `db_type` validation and connection logic in
`exesql.py` and reuse existing MySQL compatibility mode
**Frontend**
- Add OceanBase option to the ExeSQL `db_type` selector
### How to test
1. Configure OceanBase connection in ExeSQL node
(host/port/user/password/database)
2. Input: “Show 10 rows from test table”
3. Generated SQL: `SELECT * FROM test LIMIT 10;`
4. Query executes successfully and results are returned
### Screenshots
- ExeSQL db_type includes OceanBase
<img width="649" height="1015" alt="2"
src="https://github.com/user-attachments/assets/e0a5f7b9-e282-402a-8639-64c1aef8fce6"
/>
- ExeSQL test OceanBase connection
<img width="2247" height="1140" alt="test_ob"
src="https://github.com/user-attachments/assets/f16ebd93-b48e-4d18-b53f-8496581e755d"
/>
- Query results from OceanBase shown in UI
<img width="2550" height="1351" alt="1"
src="https://github.com/user-attachments/assets/b44163dc-baab-420d-b31e-b644bdcb77a9"
/>
### What problem does this PR solve?
issue:
[#10296](https://github.com/infiniflow/ragflow/issues/10296)
change:
- ExeSQL: support connecting to Trino.
- Validation: password can be empty only when db_type === "trino";
all other database types keep the existing requirement (non-empty).
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
issue：#5617
change：add IBM DB2 support in ExeSQL
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
This PR fixes incorrect naming for PostgreSQL usage by replacing all
instances of `postgresql` with the correct `postgres` in the `db_type`
field. This resolves potential configuration errors and ensures
consistency when specifying the database type.
Also fixed handling of None for `get_queue_length`
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
Co-authored-by: cucusenok <BP-116: updated readme.md>
### What problem does this PR solve?
Implemented French UI translation
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: ramin cedric <>
Co-authored-by: Liu An <asiro@qq.com>
### What problem does this PR solve?
Feat: Add retrieval tool #3221
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
