Struct ColumnMapping 

pub struct ColumnMapping {
    pub source_column: String,
    pub target_column: String,
    pub transform: Option<Option<String>>,
}

ColumnMapping : One source_column -> target_column pair, optionally carrying a transform expression that produces the value actually written.

Fields

source_column: String

Where the value comes from in the source record. A plain identifier (user_id) for a relational source, or a dotted path (profile.address.city) reaching inside a structured value for a document source. A single-segment path is exactly the bare column name this field has always carried, so pre-existing mappings are unchanged. Every segment must be a valid identifier; JSON Pointer syntax and array indices are rejected. A connector that only reads top-level fields (Postgres) refuses a dotted path as a dry-run precondition failure rather than at run time – see Capabilities.nested_source_paths.

target_column: String

transform: Option<Option<String>>

Optional restricted-CEL expression producing the value written to target_column. Omit it for a verbatim copy, which is what every mapping did before this field existed. Inside the expression value is this entry’s own source value and row.<column> reads another column of the same row – row may only be indexed by a literal column name, so the set of columns an expression reads is known before the run starts, fetched, and checked against the source schema. Deliberately restricted: an explicit allow-list of operators and functions (size, int, double, string, bool, has, startsWith, endsWith, contains, lowerAscii, upperAscii, trim, replace, split, join, substring), no I/O, no clock, no regular expressions, no iteration macros, no implicit type coercion, and both an evaluation-step and an output-size budget. Anything outside the allow-list is rejected at validation time and appears as a MappingIssue in the dry-run report, before any write.

Implementations

impl ColumnMapping

pub fn new(source_column: String, target_column: String) -> ColumnMapping

One source_column -> target_column pair, optionally carrying a transform expression that produces the value actually written.

Trait Implementations

impl Clone for ColumnMapping

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnMapping

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

Formats the value using the given formatter.

impl Default for ColumnMapping

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ColumnMapping

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ColumnMapping

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ColumnMapping

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ColumnMapping