datafusion_expr/
window_function.rs

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// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

use crate::{expr::WindowFunction, BuiltInWindowFunction, Expr, Literal};

/// Create an expression to represent the `nth_value` window function
pub fn nth_value(arg: Expr, n: i64) -> Expr {
    Expr::WindowFunction(WindowFunction::new(
        BuiltInWindowFunction::NthValue,
        vec![arg, n.lit()],
    ))
}