unitycatalog_delta_api/
column.rs

1//! Portable UC column model used by the managed-table contract.
2//!
3//! The Delta business logic derives UC columns from the Delta wire schema
4//! (`delta_columns_to_uc`) and reconstructs the wire schema from stored columns
5//! (`uc_columns_to_delta`). To keep this crate self-contained — free of
6//! `unitycatalog-common` and its generated proto types — it owns a small
7//! [`Column`] / [`ColumnTypeName`] pair mirroring the fields the contract needs.
8//!
9//! [`ColumnTypeName`]'s discriminants are identical to the generated
10//! `unitycatalog_common::models::tables::v1::ColumnTypeName`, so `as i32`
11//! round-trips across the boundary and each server's adapter can map between the
12//! two by value. The adapter is where the mapping to the server's own column type
13//! lives; the crate never sees it.
14
15/// A Unity Catalog column, the portable shape exchanged with the backend port.
16///
17/// This is the subset of the UC `Column` message the managed-table contract
18/// produces and consumes. The backend adapter maps between this and its own
19/// column representation.
20#[derive(Clone, Debug, Default, PartialEq, Eq)]
21pub struct Column {
22    /// Name of the column.
23    pub name: String,
24    /// Full data type specification as SQL / catalog-string text.
25    pub type_text: String,
26    /// Full data type specification, JSON-serialized (the original Delta type).
27    pub type_json: String,
28    /// Ordinal position of the column (starting at 0).
29    pub position: Option<i32>,
30    /// Data type name.
31    pub type_name: ColumnTypeName,
32    /// User-provided free-form description.
33    pub comment: Option<String>,
34    /// Whether the field may be null.
35    pub nullable: Option<bool>,
36    /// Partition index for the column, if it is a partition column.
37    pub partition_index: Option<i32>,
38}
39
40/// UC column data-type name.
41///
42/// Discriminants match the generated
43/// `unitycatalog_common::models::tables::v1::ColumnTypeName` so `as i32` values
44/// are interchangeable across the port boundary.
45#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, PartialOrd, Ord)]
46#[repr(i32)]
47pub enum ColumnTypeName {
48    #[default]
49    Unspecified = 0,
50    Boolean = 1,
51    Byte = 2,
52    Short = 3,
53    Int = 4,
54    Long = 5,
55    Float = 6,
56    Double = 7,
57    Date = 8,
58    Timestamp = 9,
59    String = 10,
60    Binary = 11,
61    Decimal = 12,
62    Interval = 13,
63    Array = 14,
64    Struct = 15,
65    Map = 16,
66    Char = 17,
67    Null = 18,
68    UserDefinedType = 19,
69    TimestampNtz = 20,
70    Variant = 21,
71    TableType = 22,
72}
73
74impl From<i32> for ColumnTypeName {
75    /// The inverse of `as i32`. Unknown discriminants map to
76    /// [`Unspecified`](Self::Unspecified), matching prost's open-enum behavior.
77    fn from(v: i32) -> Self {
78        match v {
79            1 => Self::Boolean,
80            2 => Self::Byte,
81            3 => Self::Short,
82            4 => Self::Int,
83            5 => Self::Long,
84            6 => Self::Float,
85            7 => Self::Double,
86            8 => Self::Date,
87            9 => Self::Timestamp,
88            10 => Self::String,
89            11 => Self::Binary,
90            12 => Self::Decimal,
91            13 => Self::Interval,
92            14 => Self::Array,
93            15 => Self::Struct,
94            16 => Self::Map,
95            17 => Self::Char,
96            18 => Self::Null,
97            19 => Self::UserDefinedType,
98            20 => Self::TimestampNtz,
99            21 => Self::Variant,
100            22 => Self::TableType,
101            _ => Self::Unspecified,
102        }
103    }
104}
unitycatalog_delta_api/column.rs

unitycatalog_delta_api/
column.rs
