sqlparse

Overview ¶

Package sqlparse turns raw SQL text into the query and expression nodes of package github.com/aita/sqlkit/sql — the inverse of sqlkit's build-then- compile flow.

This package holds only the dialect-agnostic surface: the Parser interface every frontend implements, the shared error helpers, and small conveniences such as ParseOne. It deliberately depends on nothing but the sql package, so callers who only need the abstraction do not pull a parser's (often heavy) dependency tree.

A concrete frontend lives in its own subpackage and module so its parser dependency stays isolated, for example github.com/aita/sqlkit/sqlparse/postgres, which is backed by pg_query_go. Additional dialects (MySQL, ...) can be added the same way.

Frontends are used directly, not through a global registry: import the one you need and construct its parser.

p := postgres.New()
queries, err := p.Parse("SELECT id FROM users")

Limitations ¶

sqlparse is a high-coverage importer, not a total one. Treat its output as a best-effort reconstruction of the sql AST, subject to the following:

• Partial mapping, with a raw fallback. Each frontend recognizes its full dialect grammar, but only the constructs the sql AST can model become typed nodes. When a converter meets a construct it cannot represent it reports an UnsupportedError; the frontend then deparses just that statement back to SQL and yields it as a github.com/aita/sqlkit/sql.RawSQL passthrough, so every statement the grammar accepts still produces a usable Query. Only a genuine syntax error (not an UnsupportedError) fails the whole Parse call. Inspect a result's concrete type to tell a typed node from a raw fallback.

• The raw fallback is reformatted and dialect-bound. A deparsed RawSQL is normalized by the backend's printer: comments and the original whitespace, quoting, and keyword casing are not preserved. It is rendered in its source dialect and carries no structure, so re-compiling it against a different dialect re-emits that text verbatim rather than translating it.

• Constructs that fall back rather than map to typed nodes include (non- exhaustive): RIGHT/FULL joins combined with NATURAL or USING; a subquery or derived-table source without an alias; window frame clauses and a window that references another window; GROUP BY ... WITH ROLLUP; non-constant or non-integer LIMIT/OFFSET; several multi-table UPDATE/DELETE shapes; RETURNING on the MySQL grammar; and many engine-specific DDL options, constraints, and ALTER actions.

• Coupled to the sql AST only. The package depends on nothing but the sql package; the concrete grammars (and their heavy dependency trees) live in the dialect subpackages, each its own module — see the package docs of github.com/aita/sqlkit/sqlparse/postgres and github.com/aita/sqlkit/sqlparse/mysql for backend-specific notes.