Mengembalikan ID koneksi (ID thread) untuk koneksi. Setiap koneksi memiliki ID yang unik di antara kumpulan klien yang terhubung saat ini.
SELECT CONNECTION_ID();
23786
The value returned by CONNECTION_ID() is the same type of value as displayed in the ID column of the Information Schema PROCESSLIST table, the Id column of SHOW PROCESSLIST output, and the PROCESSLIST_ID column of the Performance Schema threads table.
SELECT CONNECTION_ID();
23786