Recall & Review
beginner
What does the
length() function do in PostgreSQL?The
length() function returns the number of characters in a string. For example, length('hello') returns 5.Click to reveal answer
beginner
How do you find the position of a substring inside a string in PostgreSQL?
Use the
position(substring IN string) function. It returns the starting index of the substring or 0 if not found. For example, position('cat' IN 'concatenate') returns 4.Click to reveal answer
beginner
What will
length('') return?It returns 0 because the string is empty and has no characters.
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beginner
If
position('x' IN 'example') returns 2, what does that mean?It means the letter 'x' first appears at the 2nd character position in the string 'example'.
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intermediate
What is the difference between
length() and char_length() in PostgreSQL?Both return the number of characters in a string. They are synonyms and behave the same for normal text strings.
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What does
length('database') return?✗ Incorrect
length() counts all characters. 'database' has 8 letters.What is the result of
position('sql' IN 'postgresql')?✗ Incorrect
The substring 'sql' starts at the 8th character in 'postgresql'.
If a substring is not found, what does
position() return?✗ Incorrect
position() returns 0 when the substring is not found.Which function can be used to get the number of characters in a string?
✗ Incorrect
length() returns the count of characters in a string.What does
length(' ') return for a string with a single space?✗ Incorrect
A space is a character, so length returns 1.
Explain how to find the position of a substring within a string in PostgreSQL and what the result means.
Think about how you look for a word inside a sentence and find where it starts.
You got /5 concepts.
Describe how to get the length of a string and what the length represents.
Imagine counting letters in a word or sentence.
You got /4 concepts.