serde-sql

A fast, nom-based parser for SQL CREATE statements that builds a typed Rust AST from raw DDL and serializes it back to SQL.

If sqlparser-rs is syn for SQL, a full round-trip parser for everything, serde-sql is serde.

Parse DDL → Typed Rust schema → Modify programmatically → Serialize back to SQL

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Features

• Parses CREATE TABLE and CREATE INDEX statements
• Builds a fully typed AST covering every major SQL type in PostgreSQL, with MySQL and SQLite specifics support soon
• Index metadata: Method (BTree, Hash, GIN, GiST, BRIN, SP-GiST), storage parameters, sort/null order, opclass
• Column constraints: PRIMARY KEY, NOT NULL, UNIQUE
• Schema-level validation: Duplicate table detection, missing table/column references on index creation
• Insertion-order preserved for columns via IndexMap with fast insertions and lookups

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Usage

use serde_sql::{SqlDB, SqlType, SupportedDBs};

let sql = r#"
    CREATE TABLE IF NOT EXISTS users (
        id    UUID PRIMARY KEY,
        name  TEXT NOT NULL,
        email TEXT
    );
    CREATE INDEX ON users USING hash (id);
"#;

let db = SqlDB::from_sql(SupportedDBs::PostgreSQL, sql)?;
let users = db.tables.get("users").expect("No table named 'users' in DB");

assert_eq!(users.columns.get("id").expect("No column named 'id' in table 'users'").sql_type, SqlType::Uuid);
assert_eq!(users.primary_key.as_deref(), Some("id"));

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Supported Databases

• PostgreSQL (full support)
• MySQL and SQLite type aliases map to the same AST (lexer support soon)

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Non-Goals

• No SELECT, INSERT, UPDATE, or DELETE parsing, DDL only
• No comment preservation in serialized output
• No formatting preservation, output is generated SQL, not a round-trip of the input text
• Not a query planner or validator beyond schema structure

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Error Handling

serde_sql::error::Error covers:

• InvalidCommand: Non-CREATE statement
• InvalidType: Unrecognized SQL type
• UnexpectedToken: Malformed syntax
• UnexpectedEOF: Input ended mid-statement
• ParseFailure: Failed numeric/bool parse in index storage parameters
• InvalidMethod: Unrecognized index method
• InvalidParam: Unrecognized index storage parameter
• DuplicateIdent: Table or column defined more than once
• MissingIdent: Referencing a table or column that doesn't exist

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Links

• License: MIT License
• Changelog: CHANGELOG.md
• Contributing: CONTRIBUTING.md