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alter table tabelname add new_field_id int(5) unsigned default 0 not null auto_increment ,add primary key (new_field_id);
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alter table t2 add d timestamp;
alter table infos add ex tinyint not null default '0';
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alter table t2 drop column c;
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alter table t1 change a b integer;
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alter table t1 change b b bigint not null;
alter table infos change list list tinyint not null default '0';
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alter table t1 rename t2;
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mysql> alter table tablename change depno depno int(5) not null;
mysql> alter table tablename add index Ë÷ÒýÃû (×Ö¶ÎÃû1[£¬×Ö¶ÎÃû2 …]);
mysql> alter table tablename add index emp_name (name);
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mysql> alter table tablename add primary key(id);
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mysql> alter table tablename add unique emp_name2(cardnumber);
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mysql>alter table tablename drop index emp_name;
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mysql> ALTER TABLE table_name ADD field_name field_type;
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mysql> ALTER TABLE table_name CHANGE old_field_name new_field_name field_type;
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mysql> ALTER TABLE table_name DROP field_name;
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Explain MySQL architecture
. - The front layer
takes care of network connections and security authentications, the
middle layer does the SQL query parsing, and then the query is handled
off to the storage engine. A storage engine could be either a default
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