Struct CustomSqlConstraint 

pub struct CustomSqlConstraint { /* private fields */ }

A constraint that evaluates custom SQL expressions.

This constraint allows users to define custom validation logic using SQL expressions while preventing dangerous operations like DROP, DELETE, UPDATE, etc.

Examples

use term_guard::constraints::CustomSqlConstraint;
use term_guard::core::Constraint;

// Check that values in a column meet a custom condition
let constraint = CustomSqlConstraint::new("price > 0 AND price < 1000000", None::<String>)?;
assert_eq!(constraint.name(), "custom_sql");

// With a custom hint message
let constraint = CustomSqlConstraint::new(
    "order_date <= ship_date",
    Some("Shipping date must be after or equal to order date")
)?;

Implementations

impl CustomSqlConstraint

pub fn new( expression: impl Into<String>, hint: Option<impl Into<String>>, ) -> Result<Self>

Creates a new custom SQL constraint.

Arguments

• expression - The SQL expression to evaluate (should return a boolean)
• hint - Optional hint message to provide context when the constraint fails

Errors

Returns an error if the SQL expression contains dangerous operations

pub fn try_new( expression: impl Into<String>, hint: Option<impl Into<String>>, ) -> Result<Self>

Attempts to create a new custom SQL constraint, returning an error if validation fails.

Arguments

• expression - The SQL expression to evaluate
• hint - Optional hint message

Returns

A Result containing the constraint or a validation error

Trait Implementations

impl Clone for CustomSqlConstraint

fn clone(&self) -> CustomSqlConstraint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Constraint for CustomSqlConstraint

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 metadata(&self) -> ConstraintMetadata

Returns the metadata associated with this 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.

impl Debug for CustomSqlConstraint

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

Formats the value using the given formatter.