LENGTH

The LENGTH function in SQL returns the number of characters in a string. It's used to measure the size of text data, which can be helpful for data validation, formatting, or analysis. In some database systems, LENGTH may count characters differently for multi-byte character sets. Most SQL dialects support LENGTH, but some may use alternative names like LEN (in SQL Server) or CHAR_LENGTH. This function is particularly useful for enforcing character limits, splitting strings, or identifying anomalies in string data.