Method scalar_to_sql

datafusion/sql/src/unparser/expr.rs:1273–1521

DataFusion ScalarValues sometimes require a ast::Expr to construct. For example ScalarValue::Date32(d) corresponds to the ast::Expr CAST('datestr' as DATE)

(&self, v: &ScalarValue)

    /// DataFusion ScalarValues sometimes require a ast::Expr to construct.
    /// For example ScalarValue::Date32(d) corresponds to the ast::Expr CAST('datestr' as DATE)
    fn scalar_to_sql(&self, v: &ScalarValue) -> Result<ast::Expr> {
        match v {
            ScalarValue::Null => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Boolean(Some(b)) => {
                Ok(ast::Expr::value(ast::Value::Boolean(b.to_owned())))
            }
            ScalarValue::Boolean(None) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Float16(Some(f)) => {
                Ok(ast::Expr::value(ast::Value::Number(f.to_string(), false)))
            }
            ScalarValue::Float16(None) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Float32(Some(f)) => {
                let f_val = match f.fract() {
                    0.0 => format!("{f:.1}"),
                    _ => format!("{f}"),
                };
                Ok(ast::Expr::value(ast::Value::Number(f_val, false)))
            }
            ScalarValue::Float32(None) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Float64(Some(f)) => {
                let f_val = match f.fract() {
                    0.0 => format!("{f:.1}"),
                    _ => format!("{f}"),
                };
                Ok(ast::Expr::value(ast::Value::Number(f_val, false)))
            }
            ScalarValue::Float64(None) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Decimal32(Some(value), precision, scale) => {
                Ok(ast::Expr::value(ast::Value::Number(
                    Decimal32Type::format_decimal(*value, *precision, *scale),
                    false,
                )))
            }
            ScalarValue::Decimal32(None, ..) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Decimal64(Some(value), precision, scale) => {
                Ok(ast::Expr::value(ast::Value::Number(
                    Decimal64Type::format_decimal(*value, *precision, *scale),
                    false,
                )))
            }
            ScalarValue::Decimal64(None, ..) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Decimal128(Some(value), precision, scale) => {
                Ok(ast::Expr::value(ast::Value::Number(
                    Decimal128Type::format_decimal(*value, *precision, *scale),
                    false,
                )))
            }
            ScalarValue::Decimal128(None, ..) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Decimal256(Some(value), precision, scale) => {
                Ok(ast::Expr::value(ast::Value::Number(
                    Decimal256Type::format_decimal(*value, *precision, *scale),
                    false,
                )))
            }
            ScalarValue::Decimal256(None, ..) => Ok(ast::Expr::value(ast::Value::Null)),
            ScalarValue::Int8(Some(i)) => {
                Ok(ast::Expr::value(ast::Value::Number(i.to_string(), false)))
            }