Multiple choice technology databases

What is the output? SELECT SUBSTRING('123456', 0, 3)

  1. 123

  2. 12

  3. 123456

  4. 456
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In T-SQL, SUBSTRING(string, start, length) uses 1-based indexing. However, if start is 0, it starts 'before' the first character. For SUBSTRING('123456', 0, 3), it takes the character at index 0 (nothing), index 1 ('1'), and index 2 ('2'), resulting in '12'.

AI explanation

To answer this question, you need to understand the SUBSTRING function in SQL.

The SUBSTRING function is used to extract a substring from a given string. It takes three arguments: the input string, the starting position, and the length of the substring to be extracted.

In this case, the input string is '123456'. The starting position is 0, and the length is 3.

Using these arguments, the SUBSTRING function will extract a substring starting from the 0th position (which is the first character) with a length of 3 characters.

So, the output of the SUBSTRING('123456', 0, 3) statement will be '12'.

Therefore, the correct answer is B) 12.

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