Sql语句问题 - 其他数据库开发 / MySQL/Postgresql

例:
insert into tablename values('select * from tablename')；


我想让select * from tablename原样的放到tablename中，请问各位，sql文怎么改啊


select * from tablename 作为字符串，不让其执行!!

谢谢！！

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insert into tablename select * from tablename

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SQL code:
insert into tablename select 'select * from tablename';

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SQL code:
insert into tablename (columnname) select 'select * from tablename';

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insert into tablename(col1,col2...) select col1,col2... from tablename

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如何改成两列呢：
例:
insert into tablename(id,sqlstr) values(1,'select * from tablename')；


我想让select * from tablename原样的放到tablename中sqlstr列，请问各位，sql文怎么改啊


select * from tablename 作为字符串，不让其执行!!

谢谢！！

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SQL code:
insert into tablename(id,sqlstr) select (1,'select * from tablename')；

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SQL code:
insert into tablename(id,sqlstr) select 1,'select * from tablename'