Enum AggregateField 

pub enum AggregateField {
    CountAll,
    CountColumn(String),
    CountDistinct(String),
    Sum(String),
    Avg(String),
    Min(String),
    Max(String),
}

An aggregation field specifier.

Variants

CountAll

Count all rows.

CountColumn(String)

Count non-null values in a column.

CountDistinct(String)

Count distinct values in a column.

Sum(String)

Sum of a numeric column.

Avg(String)

Average of a numeric column.

Min(String)

Minimum value in a column.

Max(String)

Maximum value in a column.

Implementations

impl AggregateField

pub fn to_sql(&self) -> String

Build the SQL expression for this aggregate.

pub fn to_sql_dialect(&self, dialect: &dyn SqlDialect) -> String

Build the SQL expression for this aggregate, quoting the column identifier via the given dialect (backticks on MySQL, brackets on MSSQL, double quotes on Postgres/SQLite).

pub fn alias(&self) -> String

Get the alias for this aggregate.

pub fn is_count(&self) -> bool

Whether this aggregate yields an integer count.

COUNT(*), COUNT(col) and COUNT(DISTINCT col) all return SQL BIGINT/Int8, so a HAVING comparison against one must bind its threshold as an integer — binding an f64 makes the driver reject the parameter with a type mismatch (Int8 vs f64). SUM/AVG/ MIN/MAX are value-typed and keep float binding.

Trait Implementations

impl Clone for AggregateField

fn clone(&self) -> AggregateField

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AggregateField

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

Formats the value using the given formatter.