use datafusion_expr::Expr;
use datafusion_sql::unparser;
pub fn expr_to_sql_string(expr: &Expr) -> crate::Result<String> {
let ast = unparser::expr_to_sql(expr).map_err(|e| crate::Error::InvalidInput {
message: format!("failed to serialize expression to SQL: {}", e),
})?;
Ok(ast.to_string())
}