docs : Use more meaningful cnosdb examples (#7587)

This change makes the ecosystem integrations cnosdb documentation more
realistic and easy to understand.

- change examples of question and table
- modify typo and format

docs/extras/ecosystem/integrations/cnosdb.mdx

@@ -8,7 +8,7 @@ pip install cnos-connector
 ```
 
 ## Connecting to CnosDB
-You can connect to CnosDB using the SQLDatabase.from_cnosdb() method.
+You can connect to CnosDB using the `SQLDatabase.from_cnosdb()` method.
 ### Syntax
 ```python
 def SQLDatabase.from_cnosdb(url: str = "127.0.0.1:8902",
@@ -31,7 +31,6 @@ Args:
 ## Examples
 ```python
 # Connecting to CnosDB with SQLDatabase Wrapper
-from cnosdb_connector import make_cnosdb_langchain_uri
 from langchain import SQLDatabase
 
 db = SQLDatabase.from_cnosdb()
@@ -43,7 +42,7 @@ from langchain.chat_models import ChatOpenAI
 llm = ChatOpenAI(temperature=0, model_name="gpt-3.5-turbo")
 ```
 
-### SQL Chain
+### SQL Database Chain
 This example demonstrates the use of the SQL Chain for answering a question over a CnosDB.
 ```python
 from langchain import SQLDatabaseChain
@@ -51,15 +50,15 @@ from langchain import SQLDatabaseChain
 db_chain = SQLDatabaseChain.from_llm(llm, db, verbose=True)
 
 db_chain.run(
-  "What is the average fa of test table that time between November 3,2022 and November 4, 2022?"
+    "What is the average temperature of air at station XiaoMaiDao between October 19, 2022 and Occtober 20, 2022?"
 )
 ```
 ```shell
 > Entering new  chain...
-What is the average fa of test table that time between November 3, 2022 and November 4, 2022?
-SQLQuery:SELECT AVG(fa) FROM test WHERE time >= '2022-11-03' AND time < '2022-11-04'
-SQLResult: [(2.0,)]
-Answer:The average fa of the test table between November 3, 2022, and November 4, 2022, is 2.0.
+What is the average temperature of air at station XiaoMaiDao between October 19, 2022 and Occtober 20, 2022?
+SQLQuery:SELECT AVG(temperature) FROM air WHERE station = 'XiaoMaiDao' AND time >= '2022-10-19' AND time < '2022-10-20'
+SQLResult: [(68.0,)]
+Answer:The average temperature of air at station XiaoMaiDao between October 19, 2022 and October 20, 2022 is 68.0.
 > Finished chain.
 ```
 ### SQL Database Agent
@@ -73,36 +72,39 @@ agent = create_sql_agent(llm=llm, toolkit=toolkit, verbose=True)
 ```
 ```python
 agent.run(
-  "What is the average fa of test table that time between November 3, 2022 and November 4, 2022?"
+    "What is the average temperature of air at station XiaoMaiDao between October 19, 2022 and Occtober 20, 2022?"
 )
 ```
 ```shell
 > Entering new  chain...
 Action: sql_db_list_tables
 Action Input: ""
-Observation: test
-Thought:The relevant table is "test". I should query the schema of this table to see the column names.
+Observation: air
+Thought:The "air" table seems relevant to the question. I should query the schema of the "air" table to see what columns are available.
 Action: sql_db_schema
-Action Input: "test"
+Action Input: "air"
 Observation:
-CREATE TABLE test (
+CREATE TABLE air (
+	pressure FLOAT,
+	station STRING,
+	temperature FLOAT,
 	time TIMESTAMP,
-	fa BIGINT
+	visibility FLOAT
 )
 
 /*
-3 rows from test table:
-fa	time
-1	2022-11-03T06:20:11
-2	2022-11-03T06:20:11.000000001
-3	2022-11-03T06:20:11.000000002
+3 rows from air table:
+pressure	station	temperature	time	visibility
+75.0	XiaoMaiDao	67.0	2022-10-19T03:40:00	54.0
+77.0	XiaoMaiDao	69.0	2022-10-19T04:40:00	56.0
+76.0	XiaoMaiDao	68.0	2022-10-19T05:40:00	55.0
 */
-Thought:The relevant column is "fa" in the "test" table. I can now construct the query to calculate the average "fa" between the specified time range.
+Thought:The "temperature" column in the "air" table is relevant to the question. I can query the average temperature between the specified dates.
 Action: sql_db_query
-Action Input: "SELECT AVG(fa) FROM test WHERE time >= '2022-11-03' AND time < '2022-11-04'"
-Observation: [(2.0,)]
-Thought:The average "fa" of the "test" table between November 3, 2022 and November 4, 2022 is 2.0.
-Final Answer: 2.0
+Action Input: "SELECT AVG(temperature) FROM air WHERE station = 'XiaoMaiDao' AND time >= '2022-10-19' AND time <= '2022-10-20'"
+Observation: [(68.0,)]
+Thought:The average temperature of air at station XiaoMaiDao between October 19, 2022 and October 20, 2022 is 68.0.
+Final Answer: 68.0
 
 > Finished chain.
 ```