How is the substring function used in SQL Server?

2 years ago
Isabella Edwards
1 minute

In SQL Server, the SUBSTRING function is used to extract a portion of characters from a string. Its syntax is as follows:

Extract a portion of a given expression starting from a specified position and of a specified length.

  1. An expression is a string of characters from which to extract information.
  2. The position at which characters are extracted from the expression is defined as the starting point. Positions are counted from 1.
  3. “length” refers to the number of characters to be extracted.

Here are some examples of the SUBSTRING function:

  1. Extract a portion of the string:
SELECT SUBSTRING('Hello World', 7, 5);

The outcome is “World”.

  1. Extracting a portion of a field value:
SELECT SUBSTRING(column_name, 3, 4) FROM table_name;

This will extract 4 characters starting from the third position of the column_name field in the table.

  1. Extract the last few characters of a field value.
SELECT SUBSTRING(column_name, LEN(column_name) - 2, 3) FROM table_name;

Three characters will be extracted starting from the third-to-last position of the field value.

Please note that the syntax of the SUBSTRING function may vary slightly in different database management systems. The above is a common usage of the SUBSTRING function in SQL Server.

bannerAds