Parameters do not bind for MySQL custom tools

Prerequisites

I've searched the current open issues
I've updated to the latest version of Toolbox

Toolbox version

toolbox version 1.12.0+binary.windows.amd64.c97ca4d

Environment

OS type and version: Windows 11 v.25H2
How are you running Toolbox:

As a downloaded binary (e.g. from curl -o toolbox.exe "https://storage.googleapis.com/mcp-toolbox-for-databases/v%VERSION%/windows/amd64/toolbox.exe")

Database: mysql-8.0.26-winx64

Client

Client: windows command line
Version: Windows 11 command line
Example:

# Windows 11 command line (complex JSON syntax due to error: params must be a valid JSON string):
toolbox --config tools.yaml invoke search-language "{\""language\"": \""en\""}"

# tools.yaml
kind: source
name: datasets-db
type: mysql
host: 127.0.0.1
port: 3308
database: datasets
user: <user>
password: <pass>
---
kind: tool
name: search-language
type: mysql-sql
source: datasets-db
description: >-
    Retrieves all countries where language as parameter (ex: English) is spoken.
statement: |
  select name , languages from countries_data where languages LIKE CONCAT('%', $1, '%');
parameters:
  - name: language
    type: string
    description: "The searched language code (ex: ps,uz,tk,en,sm )"

Expected Behavior

Replace the positional parameter $1 and execute query from tool: search-language.

Current Behavior

Parameter $1 is not replaced with the given value.
Error: tool execution failed: error processing request: unable to execute query: Error 1054 (42S22): Unknown column '$1' in 'where clause'

Steps to reproduce?

start MySQL on localhost
invoke localhost-tool from command line

Additional Details

No response

@mihai1git

Hi @mihai1git!

The error Error 1054 (42S22): Unknown column '$1' in 'where clause' occurs because the mysql-sql tool runner uses MySQL's native prepared statement parameter syntax, which uses ? question mark placeholders rather than PostgreSQL positional placeholders ($1, $2, etc.).

Because $1 is not a MySQL placeholder syntax, MySQL's SQL parser interprets $1 as an unquoted column identifier in the WHERE clause, which fails because no such column exists.

Solution

Change $1 to ? in your statement:

kind: tool
name: search-language
type: mysql-sql
source: datasets-db
description: >-
    Retrieves all countries where language as parameter (ex: English) is spoken.
statement: |
  select name, languages from countries_data where languages LIKE CONCAT('%', ?, '%');
parameters:
  - name: language
    type: string
    description: "The searched language code (ex: ps,uz,tk,en,sm)"

Notes on Parameter Mapping:

In mysql-sql, parameters defined under parameters: are bound sequentially to each ? in the order they are declared in the YAML file.
If you have multiple parameters, ensure their order in the parameters list matches the occurrence order of ? in your statement.
If you ever need dynamic substitutions for table or column identifiers (which prepared statements don't allow), use templateParameters with {{.paramName}} syntax instead.

@mihai1git

Hi @mihai1git, feel free to refer to our doc for a working MySQL example. Thanks @UmeshCode1 for the answer.

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Parameters do not bind for MySQL custom tools #4084

Prerequisites

Toolbox version

Environment

Client

Expected Behavior

Current Behavior

Steps to reproduce?

Additional Details

Solution

Notes on Parameter Mapping:

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Parameters do not bind for MySQL custom tools #4084

Description

Prerequisites

Toolbox version

Environment

Client

Expected Behavior

Current Behavior

Steps to reproduce?

Additional Details

Activity

UmeshCode1 commented on Sep 28, 2026

Solution

Notes on Parameter Mapping:

duwenxin99 commented on Sep 29, 2026

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