Project: Druid (App Definition and Development / Database)
File: sql-multivalue-string-functions.md

id: sql-multivalue-string-functions title: "SQL multi-value string functions" sidebar_label: "Multi-value string functions" <!-- ~ 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. --> <!-- The format of the tables that describe the functions and operators should not be changed without updating the script create-sql-docs in web-console/script/create-sql-docs, because the script detects patterns in this markdown file and parse it to TypeScript file for web console --> :::info Apache Druid supports two query languages: Druid SQL and . This document describes the SQL language. ::: Druid supports string dimensions containing multiple values. This page describes the operations you can perform on multi-value string dimensions using . See and native for more information. All array references in the multi-value string function documentation can refer to multi-value string columns or `ARRAY` types. These functions are largely identical to the , but use `VARCHAR` types and behavior. Multi-value strings can also be converted to `ARRAY` types using `MVTOARRAY`, and `ARRAY` into multi-value strings via `ARRAYTOMV`. For additional details about `ARRAY` types, see . |Function|Description| |--|--| |`MVFILTERONLY(expr, arr)`|Filters multi-value `expr` to include only values contained in array `arr`.| |`MVFILTERNONE(expr, arr)`|Filters multi-value `expr` to include no values contained in array `arr`.| |`MV_LENGTH(arr)`|Returns length of the array expression.| |`MV_OFFSET(arr, long)`|Returns the array element at the 0-based index supplied, or null for an out of range index.| |`MV_ORDINAL(arr, long)`|Returns the array element at the 1-based index supplied, or null for an out of range index.| |`MV_CONTAINS(arr, expr)`|If `expr` is a scalar type, returns 1 if `arr` contains `expr`. If `expr` is an array, returns 1 if `arr` contains all elements of `expr`. Otherwise returns 0.| |`MV_OVERLAP(arr1, arr2)`|Returns 1 if `arr1` and `arr2` have any elements in common, else 0.| |`MVOFFSETOF(arr, expr)`|Returns the 0-based index of the first occurrence of `expr` in the array. If no matching elements exist in the array, returns `null` or -1 if `druid.generic.useDefaultValueForNull=true` (deprecated legacy mode).| |`MVORDINALOF(arr, expr)`|Returns the 1-based index of the first occurrence of `expr` in the array. If no matching elements exist in the array, returns `null` or `-1` if `druid.generic.useDefaultValueForNull=true` (deprecated legacy mode).| |`MV_PREPEND(expr, arr)`|Adds `expr` to the beginning of `arr`, the resulting array type determined by the type `arr`.| |`MV_APPEND(arr, expr)`|Appends `expr` to `arr`, the resulting array type determined by the type of `arr`.| |`MV_CONCAT(arr1, arr2)`|Concatenates `arr2` to `arr1`. The resulting array type is determined by the type of `arr1`.| |`MV_SLICE(arr, start, end)`|Returns the subarray of `arr` from the 0-based index start(inclusive) to end(exclusive), or `null`, if start is less than 0, greater than length of arr or greater than end.| |`MVTOSTRING(arr, str)`|Joins all elements of `arr` by the delimiter specified by `str`.| |`STRINGTOMV(str1, str2)`|Splits `str1` into an array on the delimiter specified by `str2`, which is a regular expression.| |`MVTOARRAY(str)`|Converts a multi-value string from a `VARCHAR` to a `VARCHAR ARRAY`.|