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ÈçÔÚÇ°ÃæÀý×ÓÖеÄmytable±íÖÐÔö¼ÓÒ»ÁбíʾÊÇ·ñµ¥Éísingle:
mysql> alter table mytable add column single char(1);
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½«abccsµÄsingle¼Ç¼ÐÞ¸ÄΪ“y”£º
mysql> update mytable set single='y' where name='abccs';
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mysql> select * from mytable;
+----------+------+------------+-----------+--------+
| name | | birth | birthaddr | single |
+----------+------+------------+-----------+--------+
| abccs |f | 1977-07-07 | china | y |
| mary |f | 1978-12-12 | usa | NULL |
| tom |m | 1970-09-02 | usa | NULL |
+----------+------+------------+-----------+--------+
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mysql> insert into mytable
-> values ('abc','f','1966-08-17','china','n');
Query OK, 1 row affected (0.05 sec)
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mysql> select * from mytable;
+----------+------+------------+-----------+--------+
| name | | birth | birthaddr | single |
+----------+------+------------+-----------+--------+
| abccs |f | 1977-07-07 | china | y |
| mary |f | 1978-12-12 | usa | NULL |
| tom |m | 1970-09-02 | usa | NULL |
| abc |f | 1966-08-17 | china | n |
+----------+------+------------+-----------+--------+
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