LENGTH and CHAR_LENGTH in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the length of the string 'Hello'.

SQL

SELECT [1]('Hello') AS length_value;

Drag options to blanks, or click blank then click option'

ALENGTH

BCOUNT

CSIZE

DLEN

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNT which counts rows, not string length.

Using LEN which is not standard SQL.

Using SIZE which is not a string function.

The LENGTH function returns the number of bytes in the string. It is commonly used to find string length in SQL.

2fill in blank

medium

Complete the code to find the number of characters in the string 'café'.

SQL

SELECT [1]('café') AS char_count;

Drag options to blanks, or click blank then click option'

ACHAR_LENGTH

BSIZE

CCOUNT

DLENGTH

Attempts:

3 left

💡 Hint

Common Mistakes

Using LENGTH which counts bytes, not characters.

Using COUNT which is for rows.

Using SIZE which is not a string function.

CHAR_LENGTH returns the number of characters in a string, which is important for multibyte characters like 'é'.

3fill in blank

hard

Fix the error in the code to correctly get the character length of the string 'naïve'.

SQL

SELECT [1]('naïve') AS length;

Drag options to blanks, or click blank then click option'

ALEN

BCHAR_LENGTH

CLENGTH

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Using LENGTH which counts bytes, not characters.

Using LEN which is not standard SQL.

Using COUNT which counts rows.

CHAR_LENGTH correctly counts characters including multibyte ones like 'ï'. LENGTH counts bytes which can be misleading.

4fill in blank

hard

Fill both blanks to create a query that shows both byte length and character length of 'résumé'.

SQL

SELECT [1]('résumé') AS byte_length, [2]('résumé') AS char_length;

Drag options to blanks, or click blank then click option'

ALENGTH

BCHAR_LENGTH

CLEN

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Using LEN which is not standard SQL.

Using COUNT which counts rows.

Mixing up LENGTH and CHAR_LENGTH.

LENGTH returns the byte length, while CHAR_LENGTH returns the character count, useful for strings with multibyte characters.

5fill in blank

hard

Fill all three blanks to create a query that selects the string, its byte length, and its character length from a table named words.

SQL

SELECT word, [1](word) AS byte_len, [2](word) AS char_len FROM words WHERE [3](word) > 5;

Drag options to blanks, or click blank then click option'

ALENGTH

BCHAR_LENGTH

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNT in WHERE clause which counts rows, not string length.

Using LEN which is not standard SQL.

Mixing up LENGTH and CHAR_LENGTH in the wrong places.

The query selects each word, its byte length using LENGTH, its character length using CHAR_LENGTH, and filters words with byte length greater than 5.