将所有数据从一个动态创建的表移动到另一个不包括某些列

Question

I am creating two identical tables dynamically from JSON. Lets Call Them Test1.Table , Test2.Table .

Test.Table1 is then loaded with data in it's columns by someone else.

My Issue is that now, I want to create a stored procedure that creates a stored procedure that takes all the data from Test.Table1 and inserts them into Test.Table2 , which would be easy, except I don't want to take all the columns from Test.Table1 , I want all but 3 of them.

I can't do a SELECT (col1, col2, col4, col5...etc) INTO Test.Table2 FROM Test.Table1 because the columns are dynamic every time, and the table already exists.

I can't do use a temporary table to move Test.Table1 's data into and drop the columns I don't want and insert it into Test.Table2 Because the columns wouldn't match up.

Answer 1

Here is a quick script to get you started. I created two tables in tempdb with slightly different table structures and wrote it such that you can insert from the first one to the second one where the columns match up. You can change the table structure and the query will change accordingly. The query is based on the second table. This is part of the design, you may wish to swap that around.

Use tempdb;
Go

If OBJECT_ID ('tempdb..##Temp1') is not null Drop Table ##Temp1
If OBJECT_ID('tempdb..##Temp2') is not null Drop Table ##Temp2

Create Table ##Temp1 (col1 int, col2 int, col3 int, col4 int)
Create Table ##Temp2 (col1 int, col2 int, col4 int)

Declare @max int
Declare @sql nvarchar(max)

Select @max = max(ordinal_position)
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = '##Temp2' 

Select @sql = 
STRING_AGG(
case when ordinal_position = 1 then 'Insert into ##Temp2 ('+COLUMN_NAME+',' 
when ORDINAL_POSITION = @max then COLUMN_NAME +')'
else COLUMN_NAME+', ' end,'') + string_agg (
case when ordinal_position = 1 then ' Select '+COLUMN_NAME+', ' when ORDINAL_POSITION = @max 
Then COLUMN_NAME +' From ##Temp1' else COLUMN_Name + ', ' end,'')
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = '##Temp2'

EXEC sp_executesql @sql

Hope this helps.