Struct SqlToRel

pub struct SqlToRel<'a, S: ContextProvider> { /* private fields */ }

SQL query planner and binder

This struct is used to convert a SQL AST into a LogicalPlan.

You can control the behavior of the planner by providing ParserOptions.

It performs the following tasks:

1. Name and type resolution (called “binding” in other systems). This phase looks up table and column names using the ContextProvider.
2. Mechanical translation of the AST into a LogicalPlan.

It does not perform type coercion, or perform optimization, which are done by subsequent passes.

Key interfaces are:

• Self::sql_statement_to_plan: Convert a statement (e.g. SELECT ...) into a LogicalPlan
• Self::sql_to_expr: Convert an expression (e.g. 1 + 2) into an Expr

Implementations

impl<S: ContextProvider> SqlToRel<'_, S>

pub fn sql_to_expr_with_alias( &self, sql: SQLExprWithAlias, schema: &DFSchema, planner_context: &mut PlannerContext, ) -> Result<Expr>

pub fn sql_to_expr( &self, sql: SQLExpr, schema: &DFSchema, planner_context: &mut PlannerContext, ) -> Result<Expr>

Generate a relational expression from a SQL expression

impl<'a, S: ContextProvider> SqlToRel<'a, S>

pub fn new(context_provider: &'a S) -> Self

Create a new query planner.

The query planner derives the parser options from the context provider.

pub fn new_with_options(context_provider: &'a S, options: ParserOptions) -> Self

Create a new query planner with the given parser options.

The query planner ignores the parser options from the context provider and uses the given parser options instead.

pub fn build_schema(&self, columns: Vec<SQLColumnDef>) -> Result<Schema>

impl<S: ContextProvider> SqlToRel<'_, S>

pub fn statement_to_plan(&self, statement: DFStatement) -> Result<LogicalPlan>

Generate a logical plan from an DataFusion SQL statement

pub fn sql_statement_to_plan(&self, statement: Statement) -> Result<LogicalPlan>

Generate a logical plan from an SQL statement

pub fn sql_statement_to_plan_with_context( &self, statement: Statement, planner_context: &mut PlannerContext, ) -> Result<LogicalPlan>

Generate a logical plan from an SQL statement

pub fn new_constraint_from_table_constraints( &self, constraints: &[TableConstraint], df_schema: &DFSchemaRef, ) -> Result<Constraints>

Convert each TableConstraint to corresponding Constraint