feat:新增投顾agent和nl2sqlagent

nl2sql/schema.py

@@ -0,0 +1,59 @@
+"""从 MySQL information_schema 加载并校验 NL2SQL 权威 Schema。"""
+from __future__ import annotations
+
+from typing import Any
+
+from sqlalchemy import bindparam, text
+
+from nl2sql.metadata import normalize_column_row, normalize_table_row
+
+
+TABLES_SQL = text(
+    """
+    SELECT TABLE_NAME, TABLE_COMMENT, TABLE_TYPE
+    FROM information_schema.tables
+    WHERE TABLE_SCHEMA = :database
+      AND TABLE_NAME IN :candidate_tables
+    """
+).bindparams(bindparam("candidate_tables", expanding=True))
+
+COLUMNS_SQL = text(
+    """
+    SELECT TABLE_NAME, COLUMN_NAME, COLUMN_COMMENT, DATA_TYPE,
+           IS_NULLABLE, ORDINAL_POSITION
+    FROM information_schema.columns
+    WHERE TABLE_SCHEMA = :database
+      AND TABLE_NAME IN :candidate_tables
+    ORDER BY TABLE_NAME, ORDINAL_POSITION
+    """
+).bindparams(bindparam("candidate_tables", expanding=True))
+
+
+async def load_authoritative_schema(
+    session,
+    *,
+    database: str,
+    candidate_tables: set[str] | list[str],
+) -> dict[str, list[dict[str, Any]]]:
+    """从权威元数据源加载候选表，并剔除不存在的表和孤立字段。"""
+    candidates = {str(name).strip() for name in candidate_tables if str(name).strip()}
+    if not candidates:
+        return {"tables": [], "columns": []}
+
+    params = {"database": database, "candidate_tables": sorted(candidates)}
+    table_result = await session.execute(TABLES_SQL, params)
+    column_result = await session.execute(COLUMNS_SQL, params)
+
+    tables = [
+        normalized
+        for row in table_result.mappings()
+        if (normalized := normalize_table_row(dict(row))) is not None
+        and normalized["table_name"] in candidates
+    ]
+    valid_table_names = {table["table_name"] for table in tables}
+    columns = []
+    for row in column_result.mappings():
+        normalized = normalize_column_row(dict(row))
+        if normalized["table_name"] in valid_table_names and normalized["field_name"]:
+            columns.append(normalized)
+    return {"tables": tables, "columns": columns}