Database connection guides / 数据库接入指南

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These templates match the current loader and bridges; they are not successful live-test reports. Replace credentials, hosts, databases and schemas with your values. Use a dedicated account and enforce database privileges.

Build and interpreter

npm install
npm run build

MySQL uses Node.js mysql2. GaussDB, Oracle and DM8 need Python 3.10+:

python -m pip install -r requirements.txt

The bridges use PYTHON_PATH, falling back to python. Select the interpreter where dependencies were installed. Current requirements pin py-opengauss, oracledb, dmPython and supporting packages; installation availability depends on OS/interpreter. Installed drivers do not prove working server connections.

Configuration loading

Save one complete example below as db-config.json in the process working directory. To combine connections, merge the databases arrays into one object, retain unique IDs and choose an existing ID as defaultDatabase.

Search order: <cwd>/db-config.json, <cwd>/.db-config.json, ~/.yg-multi-db-mcp.json, ~/.config/yg-multi-db-mcp/config.json. The loader does not read db-config.local.json. Setting MYSQL_HOST replaces file connections with the single MySQL connection ID default.

Set permissions explicitly per connection. The environment loader supplies false global defaults when ALLOW_INSERT_OPERATION, ALLOW_UPDATE_OPERATION, ALLOW_DELETE_OPERATION and ALLOW_DDL_OPERATION are absent; explicit connection flags avoid depending on file-level default merging. SQL checks do not replace account privileges.

mysql

MySQL uses Node.js mysql2. database selects the database; no Python is needed.

{
  "defaultDatabase": "mysql-dev",
  "defaultAllowInsert": false,
  "defaultAllowUpdate": false,
  "defaultAllowDelete": false,
  "defaultAllowDDL": false,
  "databases": [
    {
      "id": "mysql-dev",
      "type": "mysql",
      "host": "127.0.0.1",
      "port": 3306,
      "user": "readonly_user",
      "password": "replace-with-local-secret",
      "database": "app_dev",
      "allowInsert": false,
      "allowUpdate": false,
      "allowDelete": false,
      "allowDDL": false
    }
  ]
}

Test mysql-dev using db_test_connection, then query SELECT 1 AS mcp_probe using that same ID.

gaussdb

GaussDB uses py_opengauss. database selects the database; schema sets search_path. Use your actual port; 8000 is an example. Server/connector compatibility must be checked separately.

{
  "defaultDatabase": "gaussdb-dev",
  "defaultAllowInsert": false,
  "defaultAllowUpdate": false,
  "defaultAllowDelete": false,
  "defaultAllowDDL": false,
  "databases": [
    {
      "id": "gaussdb-dev",
      "type": "gaussdb",
      "host": "127.0.0.1",
      "port": 8000,
      "user": "readonly_user",
      "password": "replace-with-local-secret",
      "database": "app_dev",
      "schema": "public",
      "allowInsert": false,
      "allowUpdate": false,
      "allowDelete": false,
      "allowDDL": false
    }
  ]
}

Test gaussdb-dev using db_test_connection, then query SELECT 1 AS mcp_probe using that same ID.

oracle

Oracle uses Python oracledb in default Thin mode; this bridge does not initialize Thick mode. schema supplies the service name in host:port/service, not a table owner or SID. The database field is unused. Use qualified table names and suitable privileges for other owners.

{
  "defaultDatabase": "oracle-dev",
  "defaultAllowInsert": false,
  "defaultAllowUpdate": false,
  "defaultAllowDelete": false,
  "defaultAllowDDL": false,
  "databases": [
    {
      "id": "oracle-dev",
      "type": "oracle",
      "host": "127.0.0.1",
      "port": 1521,
      "user": "readonly_user",
      "password": "replace-with-local-secret",
      "schema": "ORCLPDB1",
      "allowInsert": false,
      "allowUpdate": false,
      "allowDelete": false,
      "allowDDL": false
    }
  ]
}

Test oracle-dev using db_test_connection, then query SELECT 1 AS mcp_probe FROM DUAL using that same ID.

dm8

DM8 uses dmPython. schema is applied using SET SCHEMA for queries and writes. Connection testing does not apply it, so verify schema access with a subsequent query. Use a trusted configured schema identifier. Vendor runtime libraries may be required; the bridge looks for an installed dmssl directory in Python site-packages and prepends it to PATH before importing dmPython. The database field is unused.

{
  "defaultDatabase": "dm8-dev",
  "defaultAllowInsert": false,
  "defaultAllowUpdate": false,
  "defaultAllowDelete": false,
  "defaultAllowDDL": false,
  "databases": [
    {
      "id": "dm8-dev",
      "type": "dm8",
      "host": "127.0.0.1",
      "port": 5236,
      "user": "readonly_user",
      "password": "replace-with-local-secret",
      "schema": "APP",
      "allowInsert": false,
      "allowUpdate": false,
      "allowDelete": false,
      "allowDDL": false
    }
  ]
}

Test dm8-dev using db_test_connection, then query SELECT 1 AS mcp_probe FROM DUAL using that same ID.

MCP clients

Codex file-based configuration:

[mcp_servers.every-db-mcp]
command = "node"
args = ["C:/tools/every-db-mcp/dist/index.js"]
cwd = "C:/tools/every-db-mcp"
enabled = true

[mcp_servers.every-db-mcp.env]
PYTHON_PATH = "C:/tools/every-db-mcp/.venv/Scripts/python.exe"

Use your actual paths; omit PYTHON_PATH for MySQL-only use. On macOS/Linux use corresponding paths such as /opt/every-db-mcp/.venv/bin/python. Do not set MYSQL_HOST for file-based multi-database access.

For clients accepting mcpServers JSON and a process working directory:

{
  "mcpServers": {
    "every-db-mcp": {
      "command": "node",
      "args": ["C:/tools/every-db-mcp/dist/index.js"],
      "cwd": "C:/tools/every-db-mcp",
      "env": {"PYTHON_PATH": "C:/tools/every-db-mcp/.venv/Scripts/python.exe"}
    }
  }
}

Client schemas differ. If cwd is unsupported, use a supported user-level configuration path. An absolute args path does not change the working directory. Reload/restart the host as required.

For single MySQL, environment configuration avoids working-directory dependence:

{
  "mcpServers": {
    "every-db-mcp": {
      "command": "node",
      "args": ["C:/tools/every-db-mcp/dist/index.js"],
      "env": {
        "MYSQL_HOST": "127.0.0.1",
        "MYSQL_PORT": "3306",
        "MYSQL_USER": "readonly_user",
        "MYSQL_PASS": "replace-with-local-secret",
        "MYSQL_DB": "app_dev",
        "ALLOW_INSERT_OPERATION": "false",
        "ALLOW_UPDATE_OPERATION": "false",
        "ALLOW_DELETE_OPERATION": "false",
        "ALLOW_DDL_OPERATION": "false"
      }
    }
  }
}

This creates ID default, not the file example's IDs.

Verify and troubleshoot

List every-db-mcp connections. Test oracle-dev, then run
SELECT 1 AS mcp_probe FROM DUAL on oracle-dev with maxRows 5.
Report the ID, database type and any error; do not modify data.

Use the appropriate ID and SQL probe. The tool's database parameter selects the ID; type chooses the driver; omission selects defaultDatabase. Projects are not automatically bound to a connection. Keep IDs and rules in project instructions, not credentials.

No configuration: check process cwd and supported filenames.
Only MySQL appears: remove inherited/client MYSQL_HOST for file connections.
Python import error: install dependencies into the PYTHON_PATH interpreter.
Oracle service error: verify listener host, port and service name in schema.
GaussDB/DM8 schema error: check schema name and privileges.
Driver installed but connection fails: verify network, version compatibility, credentials and vendor libraries separately.

Keep local credentials out of public commits. Python bridges create a connection per subprocess request, so pooling differs from MySQL. SQL dialects differ, and row limits are not isolation. The repository has no automated test script; perform a real connection test and read-only query for each actual target. No live database validation is claimed by these documentation examples.