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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"MySQL Parameter Binding Issue with sqlc Python Plugin","articleBody":"# Getting MySQL syntax error when trying to register users - Parameter binding issue\n\n## What I'm trying to do\nI'm building a FastAPI application with MySQL and using sqlc to generate my database repository code. Every time I try to register a user through my `/register` endpoint, I get a MySQL syntax error about the `?` placeholders.\n\n## The Problem\nWhenever I call my user registration endpoint, my application crashes with this error. It seems like the generated sqlc code isn't working properly with MySQL parameter binding.\n\n## Environment\n- **sqlc version**: 1.27.0\n- **Plugin**: sqlc-gen-python_1.3.0.wasm\n- **Database**: MySQL 8.0+\n- **Python**: 3.10\n- **SQLAlchemy**: 2.x\n- **MySQL Driver**: mysql-connector-python (also tested with PyMySQL)\n\n## Configuration\n```yaml\nversion: \"2\"\nplugins:\n  - name: py\n    wasm:\n      url: https://downloads.sqlc.dev/plugin/sqlc-gen-python_1.3.0.wasm\n      sha256: fbedae96b5ecae2380a70fb5b925fd4bff58a6cfb1f3140375d098fbab7b3a3c\nsql:\n  - engine: mysql\n    schema: \"database/migrations\"\n    queries: \"database/queries\"\n    codegen:\n      - out: repository\n        plugin: py\n        options:\n          package: repository\n          emit_sync_querier: true\n          emit_async_querier: true\n```\n\n## SQL Query\n```sql\n-- name: InsertUser :execresult\nINSERT INTO users (firstname, lastname, email, password) VALUES (?, ?, ?, ?);\n```\n\n## Generated Code (Problematic)\n```python\nINSERT_USER = \"\"\"-- name: insert_user \\\\:execresult\nINSERT INTO users (firstname, lastname, email, password) VALUES (?, ?, ?, ?)\n\"\"\"\n\ndef insert_user(self, *, firstname: Any, lastname: Any, email: Any, password: Any) -\u003e sqlalchemy.engine.Result:\n    return self._conn.execute(sqlalchemy.text(INSERT_USER), {\n        \"p1\": firstname,\n        \"p2\": lastname,\n        \"p3\": email,\n        \"p4\": password,\n    })\n```\n\n## Error\n```\nmysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?, ?, ?, ?)' at line 2\n\nsqlalchemy.exc.ProgrammingError: (mysql.connector.errors.ProgrammingError) 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?, ?, ?, ?)' at line 2\n[SQL: -- name: insert_user :execresult\nINSERT INTO users (firstname, lastname, email, password) VALUES (?, ?, ?, ?)\n]\n```\n\n## What I Think is Happening\nFrom my debugging, it looks like sqlc generates SQL with `?` placeholders but then the Python code tries to pass parameters as a dictionary like `{\"p1\": firstname, \"p2\": lastname}`. From what I can tell, MySQL with SQLAlchemy doesn't like this combination.\n\n## What I Expected\nI expected the generated code to just work out of the box with MySQL, like it probably does with PostgreSQL.\n\n## What I've Tried\n1. Switching from `mysql-connector-python` to `PyMySQL` - same error\n2. Looking at the generated code and trying to understand why it's not working\n3. Manually editing the generated code (but this gets overwritten when I run `sqlc generate` again)\n\n## Impact on Me\nThis is pretty frustrating because:\n- I can't use sqlc with MySQL without manually fixing the generated code every time\n- I have to either:\n  - Manually edit the generated files after every `sqlc generate` (not sustainable)\n  - Create wrapper classes to fix the parameter binding (extra work)\n  - Switch to a different tool (defeats the purpose of using sqlc)\n\n## Is this a known issue?\nI'm not sure if this is a bug or if I'm doing something wrong with my configuration. Any help would be appreciated!\n\n## Possible Solutions (from my research)\nMaybe the generated code could:\n1. Use positional parameters: `[firstname, lastname, email, password]` instead of the dictionary\n2. Or generate SQL with `:p1, :p2, :p3, :p4` instead of `?, ?, ?, ?`\n3. Or add a config option to choose the parameter style for different databases\n","author":{"url":"https://github.com/santinalbrowns","@type":"Person","name":"santinalbrowns"},"datePublished":"2025-08-14T09:05:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/90/sqlc-gen-python/issues/90"}