MySQL - Select where first character is lowercase or uppercase

You can use Ascii() function. It returns the numeric value of the leftmost character of the input string.

For lowercase first character: ASCII code of a is 97 and z is 122. So, the ASCII code of the first character should be Between 97 and 122.

SELECT word 
FROM en_dictionary 
WHERE CHAR_LENGTH(word) > 8 
  AND ASCII(word) BETWEEN 97 AND 122
ORDER BY RAND() LIMIT 10

---

For uppercase first character: ASCII code of A is 65 and Z is 90. So, the ASCII code of the first character should be Between 65 and 90.

SELECT word 
FROM en_dictionary 
WHERE CHAR_LENGTH(word) > 8 
  AND ASCII(word) BETWEEN 65 AND 90
ORDER BY RAND() LIMIT 10

Not a total answer, but way to large for a comment so i made a answer out of it.

I advice you to use a case sensitive utf8 collate like utf8_bin.
Then you don't need to use BINARY or other MySQL "hacks" to get the results you need you can simply use LIKE/BETWEEN with case sensitivity without problems.

Create table

CREATE TABLE test (

    utf8_general_ci_word VARCHAR(255) COLLATE utf8_general_ci
  , utf8_bin_word VARCHAR(255) COLLATE utf8_bin
);

INSERT INTO test (utf8_general_ci_word, utf8_bin_word) VALUES('a', 'a');
INSERT INTO test (utf8_general_ci_word, utf8_bin_word) VALUES('A', 'A');

INSERT INTO test (utf8_general_ci_word, utf8_bin_word) VALUES('b', 'b');
INSERT INTO test (utf8_general_ci_word, utf8_bin_word) VALUES('B', 'B');

Results

Query #1

    SELECT 
     utf8_general_ci_word
    FROM
     test 
    WHERE
     utf8_general_ci_word LIKE 'a%'

    ;

| utf8_general_ci_word |
| -------------------- |
| a                    |
| A                    |

---

Query #2

    SELECT 
     utf8_general_ci_word
    FROM
     test 
    WHERE
     utf8_general_ci_word LIKE BINARY 'a%'

    ;

| utf8_general_ci_word |
| -------------------- |
| a                    |

---

Query #3

    SELECT 
     utf8_bin_word
    FROM
     test 
    WHERE
     utf8_bin_word LIKE 'a%';

| utf8_bin_word |
| ------------- |
| a             |

demo

So your query would be something like

Query

SELECT
  word
FROM
  en_dictionary
WHERE
    CHAR_LENGTH(word) > 8
  AND
    word BETWEEN 'a' AND 'z'
ORDER BY
 RAND()
LIMIT 10

demo on the test data

Edited on 08-11-2019

This will miss words like 'zahn' because it's not <= 'z', use 'zzzzzzz' instead

Thanks to dnoeth 's comment and a very late sparring session later on 07-11-2019 there is indeed a bug in the SQL above for some cases..

As word BETWEEN 'a' AND 'z' is syntax sugar for word >= 'a' AND word <= 'z' this will indeed not match words greater then z like zahn or zzzzzzzzz for that matter. A valid patch for the query above is to use REPEAT('<char>', <number_of_size_of_table_column_datatype>) as the max range meaning in this case word BETWEEN 'a' AND REPEAT('z', 255)

the demo of the patch..

You can use SUBSTRING and REGEXP BINARY

SELECT word 
FROM en_dictionary 
WHERE CHAR_LENGTH(word)>8 
AND SUBSTRING(word, 1, 1) REGEXP BINARY '[A-Z]'
ORDER BY RAND() LIMIT 10

With REGEXP BINARY You can use any regex as you want, see documentation : https://dev.mysql.com/doc/refman/8.0/en/regexp.html

SUBSTRING is simply for get the first letter.

See

How to check for uppercase letters in MySQL?

MySQL Select Query - Get only first 10 characters of a value