Module diff 

AST Diff — semantic comparison of SQL expression trees.

Implements a tree edit distance algorithm inspired by the Change Distiller approach used in Python sqlglot’s diff.py. Computes a sequence of ChangeActions that transform one AST into another.

Example

use sqlglot_rust::{parse, Dialect};
use sqlglot_rust::diff::{diff, ChangeAction};

let source = parse("SELECT a, b FROM t WHERE a > 1", Dialect::Ansi).unwrap();
let target = parse("SELECT a, c FROM t WHERE a > 2", Dialect::Ansi).unwrap();
let changes = diff(&source, &target);

for change in &changes {
    println!("{change:?}");
}

Enums

AstNode

A wrapper around an AST node that can represent either statements or expressions, enabling uniform diff output.

ChangeAction

A change action describing a single difference between two ASTs.

Functions

diff

Compute the semantic diff between two SQL statements.

diff_sql

Parse two SQL strings and compute their diff.