请教单引号和双引号的问题

mysqlkumao

mysql> select 'abc';
+-----+
| abc |
+-----+
| abc |
+-----+
1 row in set (0.00 sec)
mysql> select "abc";
+-----+
| abc |
+-----+
| abc |
+-----+
1 row in set (0.00 sec)
mysql> select 'a bc';
+------+
| a bc |
+------+
| a bc |
+------+
1 row in set (0.00 sec)
mysql> select "a bc";
+------+
| a bc |
+------+
| a bc |
+------+
1 row in set (0.00 sec)

MySQL的单引号和双引号是一样的？应该有什么不同的吧？！
谢谢！

mysqlkumao

没人愿意讲讲吗？！

mysqlkumao

谢谢！
很详细，非常棒！