pub struct RowShape {
pub columns: Vec<RowCol>,
pub present_alias: Option<String>,
}Expand description
SELECT 输出的一列:SQL 别名(如 t1_title / rel0_amount)→ JSON 里的嵌套还原路径
Fields§
§columns: Vec<RowCol>列 → { jsonPath, isArray }。jsonPath 形如 ["title"] 或 ["items","amount"],
表示该列应嵌套还原到文档的哪个位置;isArray 表示该字段是关系数组(聚合还原)。
present_alias: Option<String>__present 哨兵列的别名(缺失 vs null 三态,F-07/H-01):该列存每行
「哪些标量字段显式存在」的集合。读取时标量列值为 null,仅当字段存在于
该集合才还原为 key: null,否则(缺失)不产出该键。None 表示本条语句
未查该列(如 count / 关系聚合),还原时不做存在性判定。
Implementations§
Trait Implementations§
impl StructuralPartialEq for RowShape
Auto Trait Implementations§
impl Freeze for RowShape
impl RefUnwindSafe for RowShape
impl Send for RowShape
impl Sync for RowShape
impl Unpin for RowShape
impl UnsafeUnpin for RowShape
impl UnwindSafe for RowShape
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more