Enum Expr

pub enum Expr {
    Identifier(Ident),
    CompoundIdentifier(Vec<Ident>),
    FieldIdentifier(Box<Expr>, Vec<Ident>),
    IsNull(Box<Expr>),
    IsNotNull(Box<Expr>),
    IsTrue(Box<Expr>),
    IsNotTrue(Box<Expr>),
    IsFalse(Box<Expr>),
    IsNotFalse(Box<Expr>),
    IsUnknown(Box<Expr>),
    IsNotUnknown(Box<Expr>),
    IsDistinctFrom(Box<Expr>, Box<Expr>),
    IsNotDistinctFrom(Box<Expr>, Box<Expr>),
    IsJson {
        expr: Box<Expr>,
        negated: bool,
        item_type: JsonPredicateType,
        unique_keys: bool,
    },
    InList {
        expr: Box<Expr>,
        list: Vec<Expr>,
        negated: bool,
    },
    InSubquery {
        expr: Box<Expr>,
        subquery: Box<Query>,
        negated: bool,
    },
    Between {
        expr: Box<Expr>,
        negated: bool,
        low: Box<Expr>,
        high: Box<Expr>,
    },
    Like {
        negated: bool,
        expr: Box<Expr>,
        pattern: Box<Expr>,
        escape_char: Option<EscapeChar>,
    },
    ILike {
        negated: bool,
        expr: Box<Expr>,
        pattern: Box<Expr>,
        escape_char: Option<EscapeChar>,
    },
    SimilarTo {
        negated: bool,
        expr: Box<Expr>,
        pattern: Box<Expr>,
        escape_char: Option<EscapeChar>,
    },
    BinaryOp {
        left: Box<Expr>,
        op: BinaryOperator,
        right: Box<Expr>,
    },
    SomeOp(Box<Expr>),
    AllOp(Box<Expr>),
    UnaryOp {
        op: UnaryOperator,
        expr: Box<Expr>,
    },
    Cast {
        expr: Box<Expr>,
        data_type: DataType,
    },
    TryCast {
        expr: Box<Expr>,
        data_type: DataType,
    },
    AtTimeZone {
        timestamp: Box<Expr>,
        time_zone: Box<Expr>,
    },
    Extract {
        field: String,
        expr: Box<Expr>,
    },
    Substring {
        expr: Box<Expr>,
        substring_from: Option<Box<Expr>>,
        substring_for: Option<Box<Expr>>,
    },
    Position {
        substring: Box<Expr>,
        string: Box<Expr>,
    },
    Overlay {
        expr: Box<Expr>,
        new_substring: Box<Expr>,
        start: Box<Expr>,
        count: Option<Box<Expr>>,
    },
    Trim {
        expr: Box<Expr>,
        trim_where: Option<TrimWhereField>,
        trim_what: Option<Box<Expr>>,
    },
    Collate {
        expr: Box<Expr>,
        collation: ObjectName,
    },
    Nested(Box<Expr>),
    Value(Value),
    Parameter {
        index: u64,
    },
    TypedString {
        data_type: DataType,
        value: String,
    },
    Function(Function),
    Case {
        operand: Option<Box<Expr>>,
        conditions: Vec<Expr>,
        results: Vec<Expr>,
        else_result: Option<Box<Expr>>,
    },
    Exists(Box<Query>),
    Subquery(Box<Query>),
    GroupingSets(Vec<Vec<Expr>>),
    Cube(Vec<Vec<Expr>>),
    Rollup(Vec<Vec<Expr>>),
    Row(Vec<Expr>),
    Array(Array),
    ArraySubquery(Box<Query>),
    Index {
        obj: Box<Expr>,
        index: Box<Expr>,
    },
    ArrayRangeIndex {
        obj: Box<Expr>,
        start: Option<Box<Expr>>,
        end: Option<Box<Expr>>,
    },
    LambdaFunction {
        args: Vec<Ident>,
        body: Box<Expr>,
    },
    Map {
        entries: Vec<(Expr, Expr)>,
    },
}

An SQL expression of any type.

The parser does not distinguish between expressions of different types (e.g. boolean vs string), so the caller must handle expressions of inappropriate type, like WHERE 1 or SELECT 1=1, as necessary.

Variants

Identifier(Ident)

Identifier e.g. table name or column name

CompoundIdentifier(Vec<Ident>)

Multi-part identifier, e.g. table_alias.column or schema.table.col

FieldIdentifier(Box<Expr>, Vec<Ident>)

Struct-field identifier. Expr is an arbitrary expression, returning either a table or a column. Idents are consecutive field accesses. e.g. (table.v1).v2 or (table).v1.v2

It must contain parentheses to be distinguished from a Expr::CompoundIdentifier. See also https://www.postgresql.org/docs/current/rowtypes.html#ROWTYPES-ACCESSING

The left parentheses must be put at the beginning of the expression. The first parenthesized part is the expr part, and the rest are flattened into idents. e.g., ((v1).v2.v3).v4 is equivalent to (v1).v2.v3.v4.

IsNull(Box<Expr>)

IS NULL operator

IsNotNull(Box<Expr>)

IS NOT NULL operator

IsTrue(Box<Expr>)

IS TRUE operator

IsNotTrue(Box<Expr>)

IS NOT TRUE operator

IsFalse(Box<Expr>)

IS FALSE operator

IsNotFalse(Box<Expr>)

IS NOT FALSE operator

IsUnknown(Box<Expr>)

IS UNKNOWN operator

IsNotUnknown(Box<Expr>)

IS NOT UNKNOWN operator

IsDistinctFrom(Box<Expr>, Box<Expr>)

IS DISTINCT FROM operator

IsNotDistinctFrom(Box<Expr>, Box<Expr>)

IS NOT DISTINCT FROM operator

IsJson

IS [ NOT ] JSON [ VALUE | ARRAY | OBJECT | SCALAR ]
[ { WITH | WITHOUT } UNIQUE [ KEYS ] ]

Fields

expr: Box<Expr>

negated: bool

item_type: JsonPredicateType

unique_keys: bool

InList

[ NOT ] IN (val1, val2, ...)

Fields

expr: Box<Expr>

list: Vec<Expr>

negated: bool

InSubquery

[ NOT ] IN (SELECT ...)

Fields

expr: Box<Expr>

subquery: Box<Query>

negated: bool

Between

<expr> [ NOT ] BETWEEN <low> AND <high>

Fields

expr: Box<Expr>

negated: bool

low: Box<Expr>

high: Box<Expr>

Like

LIKE

Fields

negated: bool

expr: Box<Expr>

pattern: Box<Expr>

escape_char: Option<EscapeChar>

ILike

ILIKE (case-insensitive LIKE)

Fields

negated: bool

expr: Box<Expr>

pattern: Box<Expr>

escape_char: Option<EscapeChar>

SimilarTo

<expr> [ NOT ] SIMILAR TO <pat> ESCAPE <esc_text>

Fields

negated: bool

expr: Box<Expr>

pattern: Box<Expr>

escape_char: Option<EscapeChar>

BinaryOp

Binary operation e.g. 1 + 1 or foo > bar

Fields

left: Box<Expr>

op: BinaryOperator

right: Box<Expr>

SomeOp(Box<Expr>)

Some operation e.g. foo > Some(bar), It will be wrapped in the right side of BinaryExpr

AllOp(Box<Expr>)

ALL operation e.g. foo > ALL(bar), It will be wrapped in the right side of BinaryExpr

UnaryOp

Unary operation e.g. NOT foo

Fields

op: UnaryOperator

expr: Box<Expr>

Cast

CAST an expression to a different data type e.g. CAST(foo AS VARCHAR)

Fields

expr: Box<Expr>

data_type: DataType

TryCast

TRY_CAST an expression to a different data type e.g. TRY_CAST(foo AS VARCHAR)

Fields

expr: Box<Expr>

data_type: DataType

AtTimeZone

AT TIME ZONE converts timestamp without time zone to/from timestamp with time zone with explicitly specified zone

Fields

timestamp: Box<Expr>

time_zone: Box<Expr>

Extract

EXTRACT(DateTimeField FROM <expr>)

Fields

field: String

expr: Box<Expr>

Substring

SUBSTRING(<expr> [FROM <expr>] [FOR <expr>])

Fields

expr: Box<Expr>

substring_from: Option<Box<Expr>>

substring_for: Option<Box<Expr>>

Position

POSITION(<expr> IN <expr>)

Fields

substring: Box<Expr>

string: Box<Expr>

Overlay

OVERLAY(<expr> PLACING <expr> FROM <expr> [ FOR <expr> ])

Fields

expr: Box<Expr>

new_substring: Box<Expr>

start: Box<Expr>

count: Option<Box<Expr>>

Trim

TRIM([BOTH | LEADING | TRAILING] [<expr>] FROM <expr>)
Or
TRIM([BOTH | LEADING | TRAILING] [FROM] <expr> [, <expr>])

Fields

expr: Box<Expr>

trim_where: Option<TrimWhereField>

trim_what: Option<Box<Expr>>

Collate

expr COLLATE collation

Fields

expr: Box<Expr>

collation: ObjectName

Nested(Box<Expr>)

Nested expression e.g. (foo > bar) or (1)

Value(Value)

A literal value, such as string, number, date or NULL

Parameter

Parameter Symbol e.g. $1, $1::int

Fields

index: u64

TypedString

A constant of form <data_type> 'value'. This can represent ANSI SQL DATE, TIME, and TIMESTAMP literals (such as DATE '2020-01-01'), as well as constants of other types (a non-standard PostgreSQL extension).

Fields

data_type: DataType

value: String

Function(Function)

Scalar function call e.g. LEFT(foo, 5)

Case

CASE [<operand>] WHEN <condition> THEN <result> ... [ELSE <result>] END

Note we only recognize a complete single expression as <condition>, not < 0 nor 1, 2, 3 as allowed in a <simple when clause> per https://jakewheat.github.io/sql-overview/sql-2011-foundation-grammar.html#simple-when-clause

Fields

operand: Option<Box<Expr>>

conditions: Vec<Expr>

results: Vec<Expr>

else_result: Option<Box<Expr>>

Exists(Box<Query>)

An exists expression EXISTS(SELECT ...), used in expressions like WHERE EXISTS (SELECT ...).

Subquery(Box<Query>)

A parenthesized subquery (SELECT ...), used in expression like SELECT (subquery) AS x or WHERE (subquery) = x

GroupingSets(Vec<Vec<Expr>>)

The GROUPING SETS expr.

Cube(Vec<Vec<Expr>>)

The CUBE expr.

Rollup(Vec<Vec<Expr>>)

The ROLLUP expr.

Row(Vec<Expr>)

The ROW expr. The ROW keyword can be omitted,

Array(Array)

An array constructor ARRAY[[2,3,4],[5,6,7]]

ArraySubquery(Box<Query>)

An array constructing subquery ARRAY(SELECT 2 UNION SELECT 3)

Index

A subscript expression arr[1] or map['a']

Fields

obj: Box<Expr>

index: Box<Expr>

ArrayRangeIndex

A slice expression arr[1:3]

Fields

obj: Box<Expr>

start: Option<Box<Expr>>

end: Option<Box<Expr>>

LambdaFunction

Fields

args: Vec<Ident>

body: Box<Expr>

Map

Fields

entries: Vec<(Expr, Expr)>

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a copy 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 Display for Expr

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

Formats the value using the given formatter.

impl Hash for Expr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Expr

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Expr

impl StructuralPartialEq for Expr