SUBSTRING Function

• Input must be a string literal value.
• Since the SUBSTRING function matches based on fixed numeric values, changes to the length or structure of a data field can cause your recipe to fail to properly execute.
• The SUBSTRING function requires numerical values for the starting and ending values. If you need to match strings using patterns, you should use the extract transform instead. See Extract Transform.

Basic Usage

derive type:single value:SUBSTRING('Hello, World',0,5)

Output: The string Hello is written to the new column.

Syntax and Arguments

derive type:single value:SUBSTRING(string_val,start_index,end_index)

For more information on syntax standards, see Language Documentation Syntax Notes.

string_val

String constant to be searched.

• Missing string values generate missing string results.
• String constants must be quoted ('Hello, World').
• Multiple columns and wildcards are not supported.

Usage Notes:

start_index

Index value of the character in the string to begin the substring match.

• The index of the first character of the string is 0.
• Value must be less than end_index.
• If this value is greater than the length of the string, a missing value is returned.

Usage Notes:

end_index

Index value of the character in the string that is one after the end the substring match.

• Value must be greater than start_index.
• If this value is greater than the length of the string, the end of the string is the end of match. If you know the maximum length of your data, you can use that value here.

Usage Notes:

Examples

Example - Sectional Information in Zipcodes

Source:

A US zip code contains five digits with an optional Zip+4 extension consisting of four digits. Valid zip code values can be a mixture of these formats.

Within zip code values, each digit has significance:

• Digit 1: Zip code section
• Digits 2-3: Region within section
• Digits 4-5: area or town within region
• Digits 6-9: Optional Zip+4 identifier within area or town

Here is some example data: 

Transform:

You are interested in the region and area or town identifiers within a zip code region. You can use the following transforms applied to the ZipCode column to extract this information:

derive type:single value:SUBSTRING(ZipCode,1,3)

derive type:single value:SUBSTRING(ZipCode,3,5)

• Since the string can be five or ten characters in length, you need to use the SUBSTRING function in the second transform, too. If the data is limited to five-digit zip codes, you could use the RIGHT function.

Results: