{{/* 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. */}} {{ $ref := ref . "maintenance/configurations.md" }}

Function | Description
--- | ---
##### substring(column,beginInclusive) | Get column.substring(beginInclusive). Output is a STRING.
##### substring(column,beginInclusive,endExclusive) | Get column.substring(beginInclusive,endExclusive). Output is a STRING.
##### truncate(column,width) | Truncate column by width. Output type is the same with column. If the column is a STRING, truncate(column,width) will truncate the string to width characters, namely `value.substring(0, width)`. If the column is an INT or LONG, truncate(column,width) will truncate the number with the algorithm `v - (((v % W) + W) % W)`. The `redundant` compute part is to keep the result always positive. If the column is a DECIMAL, truncate(column,width) will truncate the decimal with the algorithm: let `scaled_W = decimal(W, scale(v))`, then return `v - (v % scaled_W)`.
##### cast(value,dataType) | Get a constant value. The output is an atomic type, such as STRING, INT, BOOLEAN, etc.
##### upper(value) | Convert string column to upper case. The input should be a STRING and the output is a STRING.
##### lower(value) | Convert string column to lower case. The input should be a STRING and the output is a STRING.
##### trim(value) | Trim string column. The input should be a STRING and the output is a STRING.