Which function extracts the first N characters from a string in SQL Server or MySQL?

Which function extracts the first N characters from a string in SQL Server or MySQL?

• A. RIGHT(ColumnName, N)
• B. SUBSTRING(ColumnName, 1, N)
• C. LEFT(ColumnName, N)
• D. MID(ColumnName, 1, N)

Answer: (C)

Extracting the leftmost portion of a string is done with the LEFT function. It returns the first N characters of the string and works consistently in both SQL Server and MySQL, using the syntax LEFT(ColumnName, N). For example, LEFT(ColumnName, 5) gives the first five characters. The other options pull from different parts of the string: RIGHT takes characters from the end, so it would give the last N characters instead; MID isn’t a standard function on SQL Server (and, while MySQL supports MID as an alias for SUBSTRING, it isn’t as universally portable). You could also use SUBSTRING(ColumnName, 1, N) to achieve the same result, but LEFT is the most direct and portable way to get the first N characters.

Extracting the leftmost portion of a string is done with the LEFT function. It returns the first N characters of the string and works consistently in both SQL Server and MySQL, using the syntax LEFT(ColumnName, N). For example, LEFT(ColumnName, 5) gives the first five characters. The other options pull from different parts of the string: RIGHT takes characters from the end, so it would give the last N characters instead; MID isn’t a standard function on SQL Server (and, while MySQL supports MID as an alias for SUBSTRING, it isn’t as universally portable). You could also use SUBSTRING(ColumnName, 1, N) to achieve the same result, but LEFT is the most direct and portable way to get the first N characters.