Struct MultiExpressionEval 

pub struct MultiExpressionEval { /* private fields */ }

Evaluates multiple expressions efficiently (for SELECT projections).

Pre-compiles all expressions once, then evaluates them together for each row.

Implementations

impl MultiExpressionEval

pub fn compile(exprs: &[Expression], columns: &[String]) -> Result<Self>

Compile multiple expressions.

pub fn compile_with_aliases( exprs: &[Expression], columns: &[String], aliases: &[(String, usize)], ) -> Result<Self>

Compile multiple expressions with expression aliases.

Expression aliases map expression strings (like “SUM(amount)”) to column indices in the result row. This is used for window function ORDER BY clauses where aggregate expressions need to reference pre-computed results.

Arguments

• exprs - The expressions to compile
• columns - Column names for the result row
• aliases - Slice of (expression_name, column_index) pairs

pub fn with_params(self, params: ParamVec) -> Self

Set query parameters.

pub fn with_context(self, ctx: &ExecutionContext) -> Self

Set from execution context.

PERF: Both params and named_params share the Arc - zero cloning.

pub fn eval_all(&mut self, row: &Row) -> Result<Vec<Value>>

Evaluate all expressions for a row, returning values in order.

pub fn eval_into(&mut self, row: &Row, output: &mut Vec<Value>) -> Result<()>

Evaluate all expressions, writing results into provided buffer.

pub fn len(&self) -> usize

Number of expressions.

pub fn is_empty(&self) -> bool

Check if empty.