DISCONNECT — 终止一个数据库连接
DISCONNECT connection_name
DISCONNECT [ CURRENT ]
DISCONNECT ALL
DISCONNECT关闭一个（或者所有）到数据库的连接。
int
main(void)
{
EXEC SQL CONNECT TO testdb AS con1 USER testuser;
EXEC SQL CONNECT TO testdb AS con2 USER testuser;
EXEC SQL CONNECT TO testdb AS con3 USER testuser;
EXEC SQL DISCONNECT CURRENT; /* close con3 */
EXEC SQL DISCONNECT ALL; /* close con2 and con1 */
return 0;
}
SQL 标准中说明了DISCONNECT。