sql statement a copy of the data table to another table

Assuming a copy of a table, a table b, want a data table to the table b.

Table 1. If a and b are the same table structure.

insert into b select * from a;

2. If a table structure and b is not the same table.

insert into b(col1, col2, col3, …) select a.col1, a.col2, a.col3, … from a where …;

3. If the table does not exist b.

select * into b from a;

select a.col1, a.col2, c.col3, ... into b from a;

 

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