STRING_SPLIT (Transact-SQL)
Applies to: 
SQL Server 2016 (13.x) and later
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
SQL analytics endpoint in Microsoft Fabric
Warehouse in Microsoft Fabric
STRING_SPLIT is a table-valued function that splits a string into rows of substrings, based on a specified separator character.
Compatibility level 130
STRING_SPLIT requires the compatibility level to be at least 130. When the level is less than 130, the Database Engine is unable to find the STRING_SPLIT function.
To change the compatibility level of a database, refer to View or change the compatibility level of a database.
Note
Compatibility configuration isn't needed for STRING_SPLIT in Azure Synapse Analytics.
Transact-SQL syntax conventions
Syntax
STRING_SPLIT ( string , separator [ , enable_ordinal ] )
Arguments
string
An expression of any character type (for example, nvarchar, varchar, nchar, or char).
separator
A single character expression of any character type (for example, nvarchar(1), varchar(1), nchar(1), or char(1)) that is used as separator for concatenated substrings.
enable_ordinal
Applies to: Azure SQL Database, Azure SQL Managed Instance, Azure Synapse Analytics (serverless SQL pool only), and SQL Server 2022 (16.x) and later versions
An int or bit expression that serves as a flag to enable or disable the ordinal output column. A value of 1 enables the ordinal column. If enable_ordinal is omitted, NULL, or has a value of 0, the ordinal column is disabled.
Return types
If the ordinal output column isn't enabled, STRING_SPLIT returns a single-column table whose rows are the substrings. The name of the column is value. It returns nvarchar if any of the input arguments are either nvarchar or nchar. Otherwise, it returns varchar. The length of the return type is the same as the length of the string argument.
If the enable_ordinal argument is passed a value of 1, a second column named ordinal is returned that consists of the 1-based index values of each substring's position in the input string. The return type is bigint.
Remarks
STRING_SPLIT inputs a string that has delimited substrings and inputs one character to use as the delimiter or separator. Optionally, the function supports a third argument with a value of 0 or 1 that disables or enables, respectively, the ordinal output column.
STRING_SPLIT outputs a single-column or double-column table, depending on the enable_ordinal argument.
If enable_ordinal is
NULL, omitted, or has a value of0,STRING_SPLITreturns a single-column table whose rows contain the substrings. The name of the output column isvalue.If enable_ordinal has a value of
1, the function returns a two-column table, including theordinalcolumn that consists of the 1-based index values of the substrings in the original input string.
The enable_ordinal argument must be a constant value, not a column or variable. It must also be either a bit or int data type with a value of 0 or 1. Otherwise, the function raises an error.
The output rows might be in any order. The order isn't guaranteed to match the order of the substrings in the input string. You can override the final sort order by using an ORDER BY clause on the SELECT statement, for example, ORDER BY value or ORDER BY ordinal.
0x0000 (char(0)) is an undefined character in Windows collations and can't be included in STRING_SPLIT.
Empty zero-length substrings are present when the input string contains two or more consecutive occurrences of the delimiter character. Empty substrings are treated the same as are plain substrings. You can filter out any rows that contain the empty substring by using the WHERE clause, for example WHERE value <> ''. If the input string is NULL, the STRING_SPLIT table-valued function returns an empty table.
As an example, the following SELECT statement uses the space character as the separator:
SELECT value FROM STRING_SPLIT('Lorem ipsum dolor sit amet.', ' ');
In a practice run, the preceding SELECT returned following result table:
| value |
|---|
Lorem |
ipsum |
dolor |
sit |
amet. |
The following example enables the ordinal column by passing 1 for the optional third argument:
SELECT * FROM STRING_SPLIT('Lorem ipsum dolor sit amet.', ' ', 1);
This statement then returns the following result table:
| value | ordinal |
|---|---|
Lorem |
1 |
ipsum |
2 |
dolor |
3 |
sit |
4 |
amet. |
5 |
Examples
A. Split comma-separated value string
Parse a comma-separated list of values and return all non-empty tokens:
DECLARE @tags NVARCHAR(400) = 'clothing,road,,touring,bike'
SELECT value
FROM STRING_SPLIT(@tags, ',')
WHERE RTRIM(value) <> '';
STRING_SPLIT returns an empty string if there's nothing between separator. The condition RTRIM(value) <> '' removes empty tokens.
B. Split comma-separated value string in a column
Product table has a column with comma-separate list of tags shown in the following example:
| ProductId | Name | Tags |
|---|---|---|
1 |
Full-Finger Gloves |
clothing,road,touring,bike |
2 |
LL Headset |
bike |
3 |
HL Mountain Frame |
bike,mountain |
Following query transforms each list of tags and joins them with the original row:
SELECT ProductId, Name, value
FROM Product
CROSS APPLY STRING_SPLIT(Tags, ',');
Here's the result set.
| ProductId | Name | Value |
|---|---|---|
1 |
Full-Finger Gloves |
clothing |
1 |
Full-Finger Gloves |
road |
1 |
Full-Finger Gloves |
touring |
1 |
Full-Finger Gloves |
bike |
2 |
LL Headset |
bike |
3 |
HL Mountain Frame |
bike |
3 |
HL Mountain Frame |
mountain |
Note
The order of the output might vary as the order is not guaranteed to match the order of the substrings in the input string.
C. Aggregation by values
Users must create a report that shows the number of products per each tag, ordered by number of products, and to filter only the tags with more than two products.
SELECT value as tag, COUNT(*) AS [number_of_articles]
FROM Product
CROSS APPLY STRING_SPLIT(Tags, ',')
GROUP BY value
HAVING COUNT(*) > 2
ORDER BY COUNT(*) DESC;
D. Search by tag value
Developers must create queries that find articles by keywords. They can use following queries:
To find products with a single tag (clothing):
SELECT ProductId, Name, Tags
FROM Product
WHERE 'clothing' IN (SELECT value FROM STRING_SPLIT(Tags, ','));
Find products with two specified tags (clothing and road):
SELECT ProductId, Name, Tags
FROM Product
WHERE EXISTS (SELECT *
FROM STRING_SPLIT(Tags, ',')
WHERE value IN ('clothing', 'road'));
E. Find rows by list of values
Developers must create a query that finds articles by a list of IDs. They can use following query:
SELECT ProductId, Name, Tags
FROM Product
JOIN STRING_SPLIT('1,2,3',',')
ON value = ProductId;
The preceding STRING_SPLIT usage is a replacement for a common antipattern. Such an antipattern can involve the creation of a dynamic SQL string in the application layer or in Transact-SQL. Or an antipattern can be achieved by using the LIKE operator. See the following example SELECT statement:
SELECT ProductId, Name, Tags
FROM Product
WHERE ',1,2,3,' LIKE '%,' + CAST(ProductId AS VARCHAR(20)) + ',%';
F. Find rows by ordinal values
The following statement finds all rows with an even index value:
SELECT *
FROM STRING_SPLIT('Austin,Texas,Seattle,Washington,Denver,Colorado', ',', 1)
WHERE ordinal % 2 = 0;
The above statement returns the following table:
| value | ordinal |
|---|---|
| Texas | 2 |
| Washington | 4 |
| Colorado | 6 |
G. Order rows by ordinal values
The following statement returns the split substring values of the input string and their ordinal values, ordered by the ordinal column:
SELECT * FROM STRING_SPLIT('E-D-C-B-A', '-', 1) ORDER BY ordinal DESC;
The above statement returns the following table:
| value | ordinal |
|---|---|
| A | 5 |
| B | 4 |
| C | 3 |
| D | 2 |
| E | 1 |