Struct postgres_parser::nodes::CaseExpr

pub struct CaseExpr {
    pub casetype: Oid,
    pub casecollid: Oid,
    pub arg: Option<Box<Expr>>,
    pub args: Option<Vec<Node>>,
    pub defresult: Option<Box<Expr>>,
    pub location: i32,
}

CaseExpr a CASE expression

We support two distinct forms of CASE expression: CASE WHEN boolexpr THEN expr [ WHEN boolexpr THEN expr ... ] CASE testexpr WHEN compexpr THEN expr [ WHEN compexpr THEN expr ... ] These are distinguishable by the "arg" field being NULL in the first case and the testexpr in the second case.

In the raw grammar output for the second form, the condition expressions of the WHEN clauses are just the comparison values. Parse analysis converts these to valid boolean expressions of the form CaseTestExpr '=' compexpr where the CaseTestExpr node is a placeholder that emits the correct value at runtime. This structure is used so that the testexpr need be evaluated only once. Note that after parse analysis, the condition expressions always yield boolean.

Note: we can test whether a CaseExpr has been through parse analysis yet by checking whether casetype is InvalidOid or not.

Fields

casetype: Oid

casecollid: Oid

arg: Option<Box<Expr>>

args: Option<Vec<Node>>

defresult: Option<Box<Expr>>

location: i32

Trait Implementations

impl Debug for CaseExpr

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CaseExpr

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Eq for CaseExpr

impl PartialEq<CaseExpr> for CaseExpr

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Serialize for CaseExpr

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl StructuralEq for CaseExpr

impl StructuralPartialEq for CaseExpr