Struct JsonExprPlanner 

pub(crate) struct JsonExprPlanner;

Rewrites JSON-aware SQL expressions into DataFusion expressions.

This planner handles two cases:

• Rewrites compound identifiers on JSON extension columns into json_get function. For example, select a.b.c => select json_get(a, "b.c").
• Pushes an “expected type” argument into the json_get function when it participates in a binary operator. So that json_get knows the wanted data type when dealing with variant JSON values. For example, select json_get(a, "b.c") + 1 => select json_get(a, "b.c", NULL::Int64) + 1.

Trait Implementations

impl Debug for JsonExprPlanner

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

Formats the value using the given formatter.

impl ExprPlanner for JsonExprPlanner

fn plan_binary_op( &self, expr: RawBinaryExpr, schema: &DFSchema, ) -> Result<PlannerResult<RawBinaryExpr>>

Plan the binary operation between two expressions, returns original BinaryExpr if not possible

fn plan_compound_identifier( &self, field: &Field, qualifier: Option<&TableReference>, nested_names: &[String], ) -> Result<PlannerResult<Vec<Expr>>>

Plans compound identifier such as db.schema.table for non-empty nested names

fn plan_field_access( &self, expr: RawFieldAccessExpr, _schema: &DFSchema, ) -> Result<PlannerResult<RawFieldAccessExpr>, DataFusionError>

Plan the field access expression, such as foo.bar

fn plan_array_literal( &self, exprs: Vec<Expr>, _schema: &DFSchema, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plan an array literal, such as [1, 2, 3]

fn plan_position( &self, args: Vec<Expr>, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plan a POSITION expression, such as POSITION(<expr> in <expr>)

fn plan_dictionary_literal( &self, expr: RawDictionaryExpr, _schema: &DFSchema, ) -> Result<PlannerResult<RawDictionaryExpr>, DataFusionError>

Plan a dictionary literal, such as { key: value, ...}

fn plan_extract( &self, args: Vec<Expr>, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plan an extract expression, such asEXTRACT(month FROM foo)

fn plan_substring( &self, args: Vec<Expr>, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plan an substring expression, such as SUBSTRING(<expr> [FROM <expr>] [FOR <expr>])

fn plan_struct_literal( &self, args: Vec<Expr>, _is_named_struct: bool, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plans a struct literal, such as {'field1' : expr1, 'field2' : expr2, ...}

fn plan_overlay( &self, args: Vec<Expr>, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plans an overlay expression, such as overlay(str PLACING substr FROM pos [FOR count])

fn plan_make_map( &self, args: Vec<Expr>, ) -> Result<PlannerResult<Vec<Expr>>, DataFusionError>

Plans a make_map expression, such as make_map(key1, value1, key2, value2, ...)

fn plan_aggregate( &self, expr: RawAggregateExpr, ) -> Result<PlannerResult<RawAggregateExpr>, DataFusionError>

Plans aggregate functions, such as COUNT(<expr>)

fn plan_window( &self, expr: RawWindowExpr, ) -> Result<PlannerResult<RawWindowExpr>, DataFusionError>

Plans window functions, such as COUNT(<expr>)