Enum Expr 

pub enum Expr {
    Column {
        qual: Option<String>,
        name: String,
    },
    Literal(Value),
    Star,
    QualifiedStar(String),
    Func {
        name: String,
        args: Vec<Expr>,
    },
    Case {
        operand: Option<Box<Expr>>,
        whens: Vec<(Expr, Expr)>,
        else_: Option<Box<Expr>>,
    },
    Binary {
        op: String,
        left: Box<Expr>,
        right: Box<Expr>,
    },
    Unary {
        op: String,
        expr: Box<Expr>,
    },
    InList {
        expr: Box<Expr>,
        list: Vec<Expr>,
        negated: bool,
    },
    IsNull {
        expr: Box<Expr>,
        negated: bool,
    },
    Cast {
        expr: Box<Expr>,
        ty: String,
    },
}

Variants

Column

nspname or n.nspname. The qualifier is kept because a join makes bare names ambiguous, and resolving an ambiguous name by guessing is how a query silently reads the wrong table’s column.

Fields

qual: Option<String>

name: String

Literal(Value)

Star

* in count(*), and in a bare select list.

QualifiedStar(String)

alias.*

Func

Fields

name: String

args: Vec<Expr>

Case

Both SQL spellings: simple — CASE x WHEN 'r' THEN 'table' ... ELSE ... END searched — CASE WHEN x = 'r' THEN 'table' ... ELSE ... END psql’s \dt uses the simple form with nine branches.

Fields

operand: Option<Box<Expr>>

whens: Vec<(Expr, Expr)>

else_: Option<Box<Expr>>

Binary

Fields

op: String

left: Box<Expr>

right: Box<Expr>

Unary

Fields

op: String

expr: Box<Expr>

InList

x [NOT] IN (a, b, c)

Fields

expr: Box<Expr>

list: Vec<Expr>

negated: bool

IsNull

x IS [NOT] NULL

Fields

expr: Box<Expr>

negated: bool

Cast

x::type — the cast is PARSED and then ignored at evaluation, because this engine is dynamically typed. Ignoring it is safe for the shapes catalogue SQL uses (prattrs::int2[]), and the alternative — refusing every cast — would reject queries whose result the cast cannot change.

Fields

expr: Box<Expr>

ty: String

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.

impl PartialEq for Expr

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Expr