executor.py
8.98 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
"""
SQL 执行器模块
提供 SQL 执行、重试和错误分类功能
"""
import logging
import time
import json
from typing import Any, Dict, List, Optional, Tuple
from ..sql_agent.prompts import load_prompt, SQL_AGENT_SYSTEM_PROMPT
from ...llm import get_llm_client
from ...config import get_settings
from ...models import SQLExecutionResult
from langchain_core.messages import SystemMessage, HumanMessage
logger = logging.getLogger(__name__)
class SQLExecutor:
"""SQL 执行器 - 负责 SQL 生成、执行和重试"""
def __init__(self, db_connection=None):
self._settings = get_settings()
self._conn = db_connection
self._llm = get_llm_client()
self._max_retries = 3
self._base_delay = 1.0
def _get_connection(self):
"""获取数据库连接"""
if self._conn is None:
from ...services.db import get_connection
self._conn = get_connection()
return self._conn
def close(self):
"""关闭连接"""
if self._conn and hasattr(self._conn, 'close'):
self._conn.close()
self._conn = None
def generate_sql(
self,
question: str,
context: Optional[Dict] = None,
previous_error: Optional[str] = None,
) -> Tuple[str, str]:
"""
使用LLM生成SQL
Args:
question: 自然语言查询需求
context: 上下文信息
previous_error: 上一次执行的错误（用于重试）
Returns:
(SQL语句, 解释说明)
"""
user_prompt = question
if context:
user_prompt += f"\n\n上下文信息:\n{json.dumps(context, ensure_ascii=False, indent=2)}"
if previous_error:
user_prompt += f"\n\n上一次执行错误:\n{previous_error}\n请修正SQL语句。"
messages = [
SystemMessage(content=SQL_AGENT_SYSTEM_PROMPT),
HumanMessage(content=user_prompt),
]
response = self._llm.invoke(messages)
content = response.content.strip()
try:
# 提取JSON
if "```json" in content:
content = content.split("```json")[1].split("```")[0].strip()
elif "```" in content:
content = content.split("```")[1].split("```")[0].strip()
result = json.loads(content)
return result.get("sql", ""), result.get("explanation", "")
except json.JSONDecodeError:
logger.warning(f"无法解析LLM响应为JSON: {content[:200]}")
# 尝试直接提取SQL
if "SELECT" in content.upper():
lines = content.split("\n")
for line in lines:
if "SELECT" in line.upper():
return line.strip(), "直接提取的SQL"
return "", "解析失败"
def execute_sql(self, sql: str) -> Tuple[bool, Any, Optional[str]]:
"""
执行SQL查询
Returns:
(成功标志, 数据/None, 错误信息/None)
"""
if not sql or not sql.strip():
return False, None, "SQL语句为空"
# 安全检查：只允许SELECT语句
sql_upper = sql.upper().strip()
if not sql_upper.startswith("SELECT"):
return False, None, "只允许执行SELECT查询"
conn = self._get_connection()
cursor = conn.cursor(dictionary=True)
try:
start_time = time.time()
cursor.execute(sql)
rows = cursor.fetchall()
execution_time = int((time.time() - start_time) * 1000)
logger.info(f"SQL执行成功: 返回{len(rows)}行, 耗时{execution_time}ms")
return True, rows, None
except Exception as e:
error_msg = str(e)
logger.error(f"SQL执行失败: {error_msg}")
return False, None, error_msg
finally:
cursor.close()
def query_with_retry(
self,
question: str,
context: Optional[Dict] = None,
) -> SQLExecutionResult:
"""
带重试的查询
错误类型区分：
- SyntaxError: 立即重试，让LLM修正SQL
- OperationalError: 指数退避重试（连接超时、死锁等）
Args:
question: 查询问题
context: 上下文
Returns:
SQLExecutionResult
"""
start_time = time.time()
last_error = None
last_sql = ""
for attempt in range(self._max_retries):
# 生成SQL
sql, explanation = self.generate_sql(question, context, last_error)
last_sql = sql
if not sql:
last_error = "LLM未能生成有效的SQL语句"
logger.warning(f"重试 {attempt + 1}/{self._max_retries}: {last_error}")
if attempt < self._max_retries - 1:
delay = self._base_delay * (2 ** attempt)
time.sleep(delay)
continue
logger.info(f"尝试 {attempt + 1}: 执行SQL: {sql[:100]}...")
# 执行SQL
success, data, error, error_type = self._execute_sql_with_type(sql)
if success:
execution_time = int((time.time() - start_time) * 1000)
return SQLExecutionResult(
success=True,
sql=sql,
data=data,
retry_count=attempt,
execution_time_ms=execution_time,
)
last_error = error
logger.warning(f"重试 {attempt + 1}/{self._max_retries}: [{error_type}] {error}")
if attempt < self._max_retries - 1:
if error_type == "syntax":
# 语法错误：立即重试，不等待
logger.info("SQL语法错误，立即重试让LLM修正")
else:
# 连接/死锁等操作错误：指数退避
delay = self._base_delay * (2 ** attempt)
logger.info(f"操作错误，等待 {delay}秒 后重试...")
time.sleep(delay)
execution_time = int((time.time() - start_time) * 1000)
return SQLExecutionResult(
success=False,
sql=last_sql,
error=last_error,
retry_count=self._max_retries,
execution_time_ms=execution_time,
)
def _execute_sql_with_type(self, sql: str) -> Tuple[bool, Any, Optional[str], str]:
"""
执行SQL并返回错误类型
Returns:
(成功标志, 数据/None, 错误信息/None, 错误类型)
错误类型: "syntax" | "operational" | "unknown"
"""
if not sql or not sql.strip():
return False, None, "SQL语句为空", "unknown"
# 安全检查：只允许SELECT语句
sql_upper = sql.upper().strip()
if not sql_upper.startswith("SELECT"):
return False, None, "只允许执行SELECT查询", "syntax"
conn = self._get_connection()
cursor = conn.cursor(dictionary=True)
try:
start_time = time.time()
cursor.execute(sql)
rows = cursor.fetchall()
execution_time = int((time.time() - start_time) * 1000)
logger.info(f"SQL执行成功: 返回{len(rows)}行, 耗时{execution_time}ms")
return True, rows, None, ""
except Exception as e:
error_msg = str(e)
error_type = self._classify_error(e)
logger.error(f"SQL执行失败 [{error_type}]: {error_msg}")
return False, None, error_msg, error_type
finally:
cursor.close()
def _classify_error(self, error: Exception) -> str:
"""
分类SQL错误类型
Returns:
"syntax" - 语法错误，需要LLM修正
"operational" - 操作错误，需要指数退避
"unknown" - 未知错误
"""
error_msg = str(error).lower()
error_class = type(error).__name__
# MySQL语法错误特征
syntax_keywords = [
"syntax error", "you have an error in your sql syntax",
"unknown column", "unknown table", "doesn't exist",
"ambiguous column", "invalid", "near",
]
# 操作错误特征（需要退避）
operational_keywords = [
"timeout", "timed out", "connection", "deadlock",
"lock wait", "too many connections", "gone away",
"lost connection", "can't connect",
]
for keyword in syntax_keywords:
if keyword in error_msg:
return "syntax"
for keyword in operational_keywords:
if keyword in error_msg:
return "operational"
# 根据异常类型判断
if "ProgrammingError" in error_class or "InterfaceError" in error_class:
return "syntax"
if "OperationalError" in error_class:
return "operational"
return "unknown"