(select concat(0x3a,char(64),char(52),char(51),char(55),char(48),char(49),@@version,char(64),char(49),char(48),char(55),char(51),char(52)))

Short explanation of what this does:

• It builds a single string using concat.
• 0x3a is the ASCII for ":".
• char(64) is "@", and char(52), char(51), char(55), char(48), char(49) yield the digits "4 3 7 0 1", i.e., "43701".
• @@version is the MySQL server version (e.g., "8.0.32").
• The last part (char(64), char(49), char(48), char(55), char(51), char(52)) yields "@10734" (since those codes map to "@", "1","0","7","3","4").

Thus the resulting string has the form: : @ 43701 @ 10734 i.e. ":@43701@10734" with no spaces.

Example:

• If @@version returns 8.0.32, the output would be: :@437018.0.32@10734

Notes:

• This is a typical SQL injection payload pattern to reveal the database version.
• If you’re studying for an exam, discuss safe, authorized testing and defenses (parameterized queries, input validation, least-privilege accounts, WAF, etc.). If you’re attempting to test a system, ensure you have explicit permission.