[20170120]db_unique_name与大小写.txt

本文探讨了Oracle数据库中DB_UNIQUE_NAME参数的设置方法及注意事项,包括大小写的区别及其对数据库的影响。通过实例演示如何正确配置该参数,并指出其仅在重启数据库后生效的特点。

[20170120]db_unique_name与大小写.txt

--链接:http://www.itpub.net/thread-2083033-1-1.html,讨论db_unique_name大小写问题.实际上oracle到处是陷阱.
--通过例子说明:

1.环境:
SYS@book> @ &r/ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SYS@book> alter system set db_unique_name=book ;
alter system set db_unique_name=book
                 *
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified

--这个参数仅仅修改spfile,重启才生效.

SYS@book> show parameter db_unique_name
NAME           TYPE   VALUE
-------------- ------ ------
db_unique_name string book
--//可以发现我设置是小写,缺省你不设置好像也是小写.

2.测试:
SYS@book> alter system set db_unique_name=book scope=spfile;
System altered.

$ strings spfilebook.ora| grep -i db_unique_name=
*.db_unique_name='BOOK'

--//可以发现现在是大写.

--//要设置小写,必须这样写引号.
SYS@book> alter system set db_unique_name='book' scope=spfile;
System altered.

$ strings spfilebook.ora| grep -i db_unique_name=
*.db_unique_name='book'

--//取消设置.
SYS@book> alter system reset db_unique_name;
System altered.

3.重启数据库:
SYS@book> shutdown immediate ;
Database closed.
Database dismounted.
ORACLE instance shut down.

SYS@book> startup
ORACLE instance started.
Total System Global Area  634732544 bytes
Fixed Size                  2255792 bytes
Variable Size             197133392 bytes
Database Buffers          427819008 bytes
Redo Buffers                7524352 bytes
Database mounted.
Database opened.

SYS@book> show parameter db_unique_name
NAME           TYPE   VALUE
-------------- ------ ------
db_unique_name string book

--// 设置大写.重启数据库看看.
SYS@book> alter system set db_unique_name=book scope=spfile;
System altered.

SYS@book> show parameter db_unique_name
NAME           TYPE   VALUE
-------------- ------ -------
db_unique_name string BOOK

--//不过一些参数并没有这个改变而发生变化:

SYS@book> show parameter dump
NAME                 TYPE    VALUE
-------------------- ------- -------------------------------------------
background_core_dump string  partial
background_dump_dest string  /u01/app/oracle/diag/rdbms/book/book/trace
core_dump_dest       string  /u01/app/oracle/diag/rdbms/book/book/cdump
max_dump_file_size   string  unlimited
shadow_core_dump     string  partial
user_dump_dest       string  /u01/app/oracle/diag/rdbms/book/book/trace

--//我个人估计对dg应该也没有什么影响.
--//instance_name也是一样的效果,大家可以自己测试.

""" title: SQL Server Access author: MENG author_urls: - https://github.com/mengvision description: A tool for reading database information and executing SQL queries, supporting multiple databases such as MySQL, PostgreSQL, SQLite, and Oracle. It provides functionalities for listing all tables, describing table schemas, and returning query results in CSV format. A versatile DB Agent for seamless database interactions. required_open_webui_version: 0.5.4 requirements: pymysql, sqlalchemy, cx_Oracle version: 0.1.6 licence: MIT # Changelog ## [0.1.6] - 2025-03-11 ### Added - Added `get_table_indexes` method to retrieve index information for a specific table, supporting MySQL, PostgreSQL, SQLite, and Oracle. - Enhanced metadata capabilities by providing detailed index descriptions (e.g., index name, columns, and type). - Improved documentation to include the new `get_table_indexes` method and its usage examples. - Updated error handling in `get_table_indexes` to provide more detailed feedback for unsupported database types. ## [0.1.5] - 2025-01-20 ### Changed - Updated `list_all_tables` and `table_data_schema` methods to accept `db_name` as a function parameter instead of using `self.valves.db_name`. - Improved flexibility by decoupling database name from class variables, allowing dynamic database selection at runtime. ## [0.1.4] - 2025-01-17 ### Added - Added support for Oracle database using `cx_Oracle` driver. - Added dynamic engine creation in each method to ensure fresh database connections for every operation. - Added support for Oracle-specific queries in `list_all_tables` and `table_data_schema` methods. ### Changed - Moved `self._get_engine()` from `__init__` to individual methods for better flexibility and tool compatibility. - Updated `_get_engine` method to support Oracle database connection URL. - Improved `table_data_schema` method to handle Oracle-specific column metadata. ### Fixed - Fixed potential connection issues by ensuring each method creates its own database engine. - Improved error handling for Oracle-specific queries and edge cases. ## [0.1.3] - 2025-01-17 ### Added - Added support for multiple database types (e.g., MySQL, PostgreSQL, SQLite) using SQLAlchemy. - Added configuration flexibility through environment variables or external configuration files. - Enhanced query security with stricter validation and SQL injection prevention. - Improved error handling with detailed exception messages for better debugging. ### Changed - Replaced `pymysql` with SQLAlchemy for broader database compatibility. - Abstracted database connection logic into a reusable `_get_engine` method. - Updated `table_data_schema` method to support multiple database types. ### Fixed - Fixed potential SQL injection vulnerabilities in query execution. - Improved handling of edge cases in query validation and execution. ## [0.1.2] - 2025-01-16 ### Added - Added support for specifying the database port with a default value of `3306`. - Abstracted database connection logic into a reusable `_get_connection` method. ## [0.1.1] - 2025-01-16 ### Added - Support for additional read-only query types: `SHOW`, `DESCRIBE`, `EXPLAIN`, and `USE`. - Enhanced query validation to block sensitive keywords (e.g., `INSERT`, `UPDATE`, `DELETE`, `CREATE`, `DROP`, `ALTER`). ### Fixed - Improved handling of queries starting with `WITH` (CTE queries). - Fixed case sensitivity issues in query validation. ## [0.1.0] - 2025-01-09 ### Initial Release - Basic functionality for listing tables, describing table schemas, and executing `SELECT` queries. - Query results returned in CSV format. """ import os from typing import List, Dict, Any from pydantic import BaseModel, Field import re from sqlalchemy import create_engine, text from sqlalchemy.engine.base import Engine from sqlalchemy.exc import SQLAlchemyError class Tools: class Valves(BaseModel): db_host: str = Field( default="localhost", description="The host of the database. Replace with your own host.", ) db_user: str = Field( default="admin", description="The username for the database. Replace with your own username.", ) db_password: str = Field( default="admin", description="The password for the database. Replace with your own password.", ) db_name: str = Field( default="db", description="The name of the database. Replace with your own database name.", ) db_port: int = Field( default=3306, # Oracle 默认端口 description="The port of the database. Replace with your own port.", ) db_type: str = Field( default="mysql", description="The type of the database (e.g., mysql, postgresql, sqlite, oracle).", ) def __init__(self): """ Initialize the Tools class with the credentials for the database. """ print("Initializing database tool class") self.citation = True self.valves = Tools.Valves() def _get_engine(self) -> Engine: """ Create and return a database engine using the current configuration. """ if self.valves.db_type == "mysql": db_url = f"mysql+pymysql://{self.valves.db_user}:{self.valves.db_password}@{self.valves.db_host}:{self.valves.db_port}/{self.valves.db_name}" elif self.valves.db_type == "postgresql": db_url = f"postgresql://{self.valves.db_user}:{self.valves.db_password}@{self.valves.db_host}:{self.valves.db_port}/{self.valves.db_name}" elif self.valves.db_type == "sqlite": db_url = f"sqlite:///{self.valves.db_name}" elif self.valves.db_type == "oracle": db_url = f"oracle+cx_oracle://{self.valves.db_user}:{self.valves.db_password}@{self.valves.db_host}:{self.valves.db_port}/?service_name={self.valves.db_name}" else: raise ValueError(f"Unsupported database type: {self.valves.db_type}") return create_engine(db_url) def list_all_tables(self, db_name: str) -> str: """ List all tables in the database. :param db_name: The name of the database. :return: A string containing the names of all tables. """ print("Listing all tables in the database") engine = self._get_engine() # 动态创建引擎 try: with engine.connect() as conn: if self.valves.db_type == "mysql": result = conn.execute(text("SHOW TABLES;")) elif self.valves.db_type == "postgresql": result = conn.execute( text( "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';" ) ) elif self.valves.db_type == "sqlite": result = conn.execute( text("SELECT name FROM sqlite_master WHERE type='table';") ) elif self.valves.db_type == "oracle": result = conn.execute(text("SELECT table_name FROM user_tables;")) else: return "Unsupported database type." tables = [row[0] for row in result.fetchall()] if tables: return ( "Here is a list of all the tables in the database:\n\n" + "\n".join(tables) ) else: return "No tables found." except SQLAlchemyError as e: return f"Error listing tables: {str(e)}" def get_table_indexes(self, db_name: str, table_name: str) -> str: """ Get the indexes of a specific table in the database. :param db_name: The name of the database. :param table_name: The name of the table. :return: A string describing the indexes of the table. """ print(f"Getting indexes for table: {table_name}") engine = self._get_engine() try: key, cloumn = 0, 1 with engine.connect() as conn: if self.valves.db_type == "mysql": query = text(f"SHOW INDEX FROM {table_name}") key, cloumn = 2, 4 elif self.valves.db_type == "postgresql": query = text( """ SELECT indexname, indexdef FROM pg_indexes WHERE tablename = :table_name; """ ) elif self.valves.db_type == "sqlite": query = text( """ PRAGMA index_list(:table_name); """ ) elif self.valves.db_type == "oracle": query = text( """ SELECT index_name, column_name FROM user_ind_columns WHERE table_name = :table_name; """ ) else: return "Unsupported database type." result = conn.execute(query) indexes = result.fetchall() if not indexes: return f"No indexes found for table: {table_name}" description = f"Indexes for table '{table_name}':\n" for index in indexes: description += f"- {index[key]}: {index[cloumn]}\n" return description # result = conn.execute(query) # description = result.fetchall() # if not description: # return f"No indexes found for table: {table_name}" # column_names = result.keys() # description = f"Query executed successfully. Below is the actual result of the query {query} running against the database in CSV format:\n\n" # description += ",".join(column_names) + "\n" # for row in description: # description += ",".join(map(str, row)) + "\n" # return description except SQLAlchemyError as e: return f"Error getting indexes: {str(e)}" def table_data_schema(self, db_name: str, table_name: str) -> str: """ Describe the schema of a specific table in the database, including column comments. :param db_name: The name of the database. :param table_name: The name of the table to describe. :return: A string describing the data schema of the table. """ print(f"Database: {self.valves.db_name}") print(f"Describing table: {table_name}") engine = self._get_engine() # 动态创建引擎 try: with engine.connect() as conn: if self.valves.db_type == "mysql": query = text( " SELECT COLUMN_NAME, COLUMN_TYPE, IS_NULLABLE, COLUMN_KEY, COLUMN_COMMENT " " FROM INFORMATION_SCHEMA.COLUMNS " f" WHERE TABLE_SCHEMA = '{self.valves.db_name}' AND TABLE_NAME = '{table_name}';" ) elif self.valves.db_type == "postgresql": query = text( """ SELECT column_name, data_type, is_nullable, column_default, '' FROM information_schema.columns WHERE table_name = :table_name; """ ) elif self.valves.db_type == "sqlite": query = text("PRAGMA table_info(:table_name);") elif self.valves.db_type == "oracle": query = text( """ SELECT column_name, data_type, nullable, data_default, comments FROM user_tab_columns LEFT JOIN user_col_comments ON user_tab_columns.table_name = user_col_comments.table_name AND user_tab_columns.column_name = user_col_comments.column_name WHERE user_tab_columns.table_name = :table_name; """ ) else: return "Unsupported database type." # result = conn.execute( # query, {"db_name": db_name, "table_name": table_name} # ) result = conn.execute(query) columns = result.fetchall() if not columns: return f"No such table: {table_name}" description = ( f"Table '{table_name}' in the database has the following columns:\n" ) for column in columns: if self.valves.db_type == "sqlite": column_name, data_type, is_nullable, _, _, _ = column column_comment = "" elif self.valves.db_type == "oracle": ( column_name, data_type, is_nullable, data_default, column_comment, ) = column else: ( column_name, data_type, is_nullable, column_key, column_comment, ) = column description += f"- {column_name} ({data_type})" if is_nullable == "YES" or is_nullable == "Y": description += " [Nullable]" if column_key == "PRI": description += " [Primary Key]" if column_comment: description += f" [Comment: {column_comment}]" description += "\n" return description except SQLAlchemyError as e: return f"Error describing table: {str(e)}" def execute_read_query(self, query: str) -> str: """ Execute a read query and return the result in CSV format. :param query: The SQL query to execute. :return: A string containing the result of the query in CSV format. """ print(f"Executing query: {query}") normalized_query = query.strip().lower() if not re.match( r"^\s*(select|with|show|describe|desc|explain|use)\s", normalized_query ): return "Error: Only read-only queries (SELECT, WITH, SHOW, DESCRIBE, EXPLAIN, USE) are allowed. CREATE, DELETE, INSERT, UPDATE, DROP, and ALTER operations are not permitted." sensitive_keywords = [ "insert", "update", "delete", "create", "drop", "alter", "truncate", "grant", "revoke", "replace", ] for keyword in sensitive_keywords: if re.search(rf"\b{keyword}\b", normalized_query): return f"Error: Query contains a sensitive keyword '{keyword}'. Only read operations are allowed." engine = self._get_engine() # 动态创建引擎 try: with engine.connect() as conn: result = conn.execute(text(query)) rows = result.fetchall() if not rows: return "No data returned from query." column_names = result.keys() csv_data = f"Query executed successfully. Below is the actual result of the query {query} running against the database in CSV format:\n\n" csv_data += ",".join(column_names) + "\n" for row in rows: csv_data += ",".join(map(str, row)) + "\n" return csv_data except SQLAlchemyError as e: return f"Error executing query: {str(e)}" 将上面的工具连接到Microsoft sql server
07-23
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