Function datafusion::sql::unparser::expr_to_sql

pub fn expr_to_sql(expr: &Expr) -> Result<Expr, DataFusionError>

Convert a DataFusion Expr to sqlparser::ast::Expr

This function is the opposite of SqlToRel::sql_to_expr and can be used to, among other things, convert Exprs to strings. Throws an error if Expr can not be represented by an sqlparser::ast::Expr

Example

use datafusion_expr::{col, lit};
use datafusion_sql::unparser::expr_to_sql;
let expr = col("a").gt(lit(4));
let sql = expr_to_sql(&expr).unwrap();

assert_eq!(format!("{}", sql), "(a > 4)")