How to copy table structure and table data in MySQL

1, copy table structure and data to new table

create table new_table_name select * from old_table_name;

One of the worst aspects of this method is that the new table does not have the primary key, Extra (auto_increment) and other attributes of the old table.

2, only copy the table structure to the new table

create table new_table_name select * from old_table_name where 1=2;

or

create table new_table_name like old_table_name;

3. Copy the data of the old table to the new table (assuming the two tables have the same structure)

insert into new_table_name select * from old_table_name;

4. Copy the data from the old table to the new table (assuming the two tables have different structures)

insert into new_table_name(field1,field2,field3) select (field1,field2,field3) from old_table_name;

5. The tables are not in the same database (eg: db1 table1, db2 table2)

Full copy

insert into db1.table1 select * from db2.table2;

Do not copy duplicate records

insert into db1.table1 select distinct* from db2.table2;

Copy the first 10 records

insert into db1.table1 select 10* from db2.table2;

6. View the SQL created for the table

show create table table_name;

This will list the table's creation SQL.We just need to copy the SQL and change the table_name to create an identical table.

7. Clear table data

delete from table_name;

or

truncate table table_name;

The delete statement without the where parameter can delete all the contents in the mysql table;
Use truncate table to also clear all the contents in the mysql table.

But using delete to clear the records in the table, the ID of the content is still established from the ID of the deletion point instead of starting from 1.

And truncate is equivalent to preserving the structure of the table and re-establishing a new same table.

Truncate is faster than delete in efficiency.

But mysql log is not recorded after truncate is deleted, and data cannot be recovered.

The effect of delete is a bit like deleting all records in the mysql table one by one until the deletion is complete.

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