Struct SetQuery 

pub struct SetQuery { /* private fields */ }

集合运算查询，支持链式追加多个 SELECT 并以 UNION/INTERSECT/EXCEPT 连接。

示例

use sz_orm_core::DbType;
use sz_orm_query_builder::Query;

let q1 = Query::select().column("id").from("active_users");
let q2 = Query::select().column("id").from("pending_users");
let sql = q1.union(q2).build(DbType::MySQL);
// SELECT `id` FROM `active_users` UNION SELECT `id` FROM `pending_users`

Implementations

impl SetQuery

pub fn new(first: SelectQuery, op: SetOperator, second: SelectQuery) -> Self

创建一个集合运算查询。

pub fn union(self, other: SelectQuery) -> Self

追加 UNION 查询。

pub fn union_all(self, other: SelectQuery) -> Self

追加 UNION ALL 查询。

pub fn intersect(self, other: SelectQuery) -> Self

追加 INTERSECT 查询。

pub fn except(self, other: SelectQuery) -> Self

追加 EXCEPT 查询。

pub fn order_by(self, column: &str, asc: bool) -> Self

设置全局 ORDER BY（作用于整个集合运算结果）。

pub fn limit(self, n: u64) -> Self

设置全局 LIMIT。

pub fn offset(self, n: u64) -> Self

设置全局 OFFSET。

pub fn build(self, db_type: DbType) -> String

生成 SQL。

将所有子查询用对应的集合运算符连接，并在末尾追加全局 ORDER BY / LIMIT / OFFSET。

Trait Implementations

impl Clone for SetQuery

fn clone(&self) -> SetQuery

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SetQuery

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.