SQL Server replication table structure to a specified table

Q: May I ask the expert how to copy the structure of other tables to a specified table, such as the following example:

The following three tables are available:

Table A: Field 1, Field 2, Field 3

Table B: Field 1, Field 2, Field 3

Table C: Field 1, Field 2, Field 3

Now you want to copy the fields of table a 1,b The fields of table 2,c table 3 to table 4. The data in the table is not required.

How should you implement SQL statements?

A: In fact, here need to consider a problem, the specified table to the table is not empty? Therefore, we have the following two kinds of situations to say separately:

/*table4不存在时*/
select a.col1, b.col2, c.col3
into table4
from tableA a, tableB b, tableC c
where 1 = 0

However, if Table 4 already exists, an error will be made. If you want to add these fields to table 4, the data for those fields does not need to be added to table 4

　　select
　　*
into 表5
from
　　表4 m
left join
　　(select a.字段1,b.字段2,c.字段3 from 表A a,表B b,表C c where 1<>1) n
on
　　1=1
　　drop table 表4
　　exec sp_rename '表5','表4'