sql_builder

一个 100% 对齐 huandu/go-sqlbuilder 设计的 Rust crate。它提供：

• Args + Flavor：支持 ?、$1、@p1、:1 等多种占位符策略，并且允许通过 Flavor 跟随不同 SQL 方言；
• 完整的各类 Builder：SelectBuilder、InsertBuilder、UpdateBuilder、DeleteBuilder、UnionBuilder、CTEBuilder、CTEQueryBuilder、CreateTableBuilder，同时内建查、插、改、删、聚合、CTE、Union 和 clone 重用模式；
• Build/Buildf/BuildNamed：支持 ${name}、$0、$?、$$、Raw、List、Tuple 等语法，并支持嵌套 builder、named arg 重用、literal $ 等特殊行为；
• Struct + field_mapper：通过 macro_rules! 生成 FieldMeta，支持 db/fieldtag/fieldopt/fieldas、with_tag/without_tag、自定义 field mapper（如 snake_case/kebab_case/prefix/suffix）并兼容 SqlValuer；
• Scan + ScanCell：仿照 Go 的 Addr 实现数据扫描；
• interpolate：为不支持参数化的驱动提供 SQL 插值，涵盖多 flavor 的字符串/数字/日期/布尔等转义；
• SqlValuer：支持延迟计算参数，兼容自定义数据源；
• 全部示例/单测对齐 Go：138 条单测 + doc-test，覆盖 README 中的 builder、Struct、CTE、Union、field mapper、命名参数等场景。

典型用法

创建 SELECT

use halo::sqlx::select::SelectBuilder;

let mut sb = SelectBuilder::new();
sb.select(["id"]).from(["user"]);
sb.where_([sb.in_("status", [1_i64, 2, 3])]);

let (sql, args) = sb.build();
assert_eq!(sql, "SELECT id FROM user WHERE status IN (?, ?, ?)");
assert_eq!(args.len(), 3);

嵌套 Builder / Buildf

use halo::sqlx::builder::buildf;

let mut sb = SelectBuilder::new();
sb.select(["id"]).from(["user"]);

let explain = buildf(
    "EXPLAIN %v LEFT JOIN SELECT * FROM banned WHERE state IN (%v, %v)",
    [sb.into(), 1_i64, 2_i64],
);
let (sql, _) = explain.build();
assert!(sql.contains("EXPLAIN SELECT id FROM user"));

named 参数

use halo::sqlx::{
    builder::build_named,
    modifiers::{SqlNamedArg, raw, list},
};

let mut named = std::collections::HashMap::new();
named.insert("table".to_string(), raw("user"));
named.insert("status".to_string(), list([1_i64, 2, 3]));
named.insert("time".to_string(), SqlNamedArg::new("start", 1_514_458_225_i64).into());

let (sql, args) = build_named(
    "SELECT * FROM ${table} WHERE status IN (${status}) AND created_at > ${time}",
    named,
)
.build();
assert!(sql.contains("@start"));

Struct ORM + field mapper

use halo::sqlx::{field_mapper::snake_case_mapper, Struct};

let _= halo::sqlx::field_mapper::set_default_field_mapper_scoped(std::sync::Arc::new(snake_case_mapper));

halo::sqlx::sql_struct! {
    impl User {
        id: { db: "id", tags: [], omitempty: [], quote: false, as: None },
        user_name: { db: "", tags: [], omitempty: [], quote: false, as: None }
    }
}

    let s = Struct::<User>::new();
let (sql, _) = s.select_from("user").build();
assert!(sql.contains("user.user_name"));

CTE 与 Union

use halo::sqlx::{cte::with, cte_query::CTEQueryBuilder, select::SelectBuilder};

let mut users_cte = CTEQueryBuilder::new();
let mut query = SelectBuilder::new();
query.select(["id"]).from(["users"]).where_(["name IS NOT NULL"]);
users_cte.table("users", ["id"]).as_(query);

let cte = with([users_cte]);
let mut sb = cte.select(["users.id"]);
sb.from(["users"]);
let (sql, _) = sb.build();
assert!(sql.contains("WITH users"));

维护与测试

cargo fmt
cargo clippy --all-targets --all-features -- -D warnings
cargo test

许可证

MIT