Struct CrossTableSumConstraint 

pub struct CrossTableSumConstraint { /* private fields */ }

Cross-table sum constraint for validating that sums from different tables match.

This constraint ensures that aggregated sums from one table match the sums from another table, optionally grouped by common columns. This is essential for validating referential integrity of financial data, inventory tracking, or any scenario where related tables should have consistent totals.

The constraint supports:

• Qualified column names (table.column format)
• GROUP BY columns for validating sums within groups
• Configurable tolerance for floating-point comparisons
• Detailed violation reporting with specific group information
• Performance optimization through efficient SQL generation

Implementations

impl CrossTableSumConstraint

pub fn new( left_column: impl Into<String>, right_column: impl Into<String>, ) -> Self

Create a new cross-table sum constraint.

Arguments

• left_column - Column specification for left side sum (table.column format)
• right_column - Column specification for right side sum (table.column format)

Examples

use term_guard::constraints::CrossTableSumConstraint;

let constraint = CrossTableSumConstraint::new("orders.total", "payments.amount");

pub fn group_by(self, columns: Vec<impl Into<String>>) -> Self

Set the GROUP BY columns for the comparison.

When specified, sums will be compared within each group rather than as a single total. This is useful for validating consistency at a more granular level.

Examples

use term_guard::constraints::CrossTableSumConstraint;

let constraint = CrossTableSumConstraint::new("orders.total", "payments.amount")
    .group_by(vec!["customer_id", "order_date"]);

pub fn tolerance(self, tolerance: f64) -> Self

Set the tolerance for floating-point comparisons.

When tolerance is greater than 0.0, sums are considered equal if their absolute difference is within the tolerance. This is useful for handling floating-point precision issues.

Examples

use term_guard::constraints::CrossTableSumConstraint;

let constraint = CrossTableSumConstraint::new("orders.total", "payments.amount")
    .tolerance(0.01); // Allow 1 cent difference

pub fn max_violations_reported(self, max_violations: usize) -> Self

Set the maximum number of violation examples to report.

Defaults to 100. Set to 0 to disable violation example collection.

pub fn left_column(&self) -> &str

Get the left column specification

pub fn right_column(&self) -> &str

Get the right column specification

pub fn group_by_columns(&self) -> &[String]

Get the group by columns

Trait Implementations

impl Clone for CrossTableSumConstraint

fn clone(&self) -> CrossTableSumConstraint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Constraint for CrossTableSumConstraint

fn evaluate<'life0, 'life1, 'async_trait>( &'life0 self, ctx: &'life1 SessionContext, ) -> Pin<Box<dyn Future<Output = Result<ConstraintResult>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Evaluates the constraint against the data in the session context.

fn name(&self) -> &str

Returns the name of the constraint.

fn column(&self) -> Option<&str>

Returns the column this constraint operates on (if single-column).

fn description(&self) -> Option<&str>

Returns a description of what this constraint validates.

fn metadata(&self) -> ConstraintMetadata

Returns the metadata associated with this constraint.

impl Debug for CrossTableSumConstraint

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CrossTableSumConstraint

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for CrossTableSumConstraint

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

where __S: Serializer,

Serialize this value into the given Serde serializer.