CREATE AS SELECT * but with one column obtained from another table - sql

Question

I need to 'recreate' over 50 tables (in Oracle) with CREATE AS SELECT statements. However, all this tables will have one column modified using data from another table. Is there a way to achieve this without declaring each column in the SELECT statement?
Something like:
CREATE TABLE table_name_copy AS SELECT *, (SELECT col_name FROM other_table WHERE other_table.col_id = table_name.col_id) AS col_name FROM table_name`
Basically on all tables I have a column which needs to be replaced with the data in the other_table column.

Answer 1

Generate the SQL string as such:
SELECT 'CREATE TABLE table_name_copy AS SELECT '
|| LISTAGG (column_name, ', ') WITHIN GROUP (ORDER BY column_name)
|| ', (SELECT col_name FROM other_table
WHERE other_table.col_id = table_name.col_id) AS col_name'
|| ' FROM table_name'
FROM all_tab_cols
WHERE owner = 'OWNER'
AND table_name = 'TABLE_NAME'
AND column_name != 'COL_NAME'
If you want to run the above statement, you could use EXECUTE IMMEDIATE:
DECLARE
v_sql VARCHAR2(10000);
BEGIN
SELECT 'CREATE TABLE table_name_copy AS SELECT '
|| LISTAGG (column_name, ', ') WITHIN GROUP (ORDER BY column_name)
|| ', (SELECT col_name FROM other_table
WHERE other_table.col_id = table_name.col_id) AS col_name'
|| ' FROM table_name'
INTO v_sql
FROM all_tab_cols
WHERE owner = 'OWNER'
AND table_name = 'TABLE_NAME'
AND column_name != 'COL_NAME';
EXECUTE IMMEDIATE v_sql;
END;
/

Answer 2

If col_id column is fixed for both of the joined tables,
you may use user_tab_columns and user_tables dictionary views through the schema to produce new tables named as "table_name_copy" by using the following mechanism :
declare
v_ddl varchar2(4000);
v_cln varchar2(400);
begin
for c in ( select *
from user_tables t
where t.table_name in
( select c.table_name
from user_tab_columns c
where c.column_name = 'COL_ID' )
order by t.table_name )
loop
v_ddl := 'create table '||c.table_name||'_copy as
select ';
for d in ( select listagg('t1.'||column_name, ',') within group ( order by column_name ) cln
from user_tab_columns
where table_name = c.table_name
and column_name != 'COL_ID' )
loop
v_cln := v_cln||d.cln;
end loop;
v_ddl := v_ddl||v_cln;
v_ddl := v_ddl||', t2.col_id t2_id
from '||c.table_name||' t1
left outer join other_table t2 on ( t1.col_id = t2.col_id )';
execute immediate v_ddl;
v_ddl := null;
v_cln := null;
end loop;
end;

Answer 3

Maybe you can use a simple join and an asterisk to return all columns from the first table, like that:
CREATE TABLE table_name_copy AS
SELECT * FROM (
SELECT tab1.*, tab2.column_name
FROM table_name tab1 LEFT JOIN other_table tab2 ON tab1.col_id = tab2.col_id
);

Answer 4

I would try this (but I don't have Oracle SQL to test on so please leave me the benefit of the doubt)
CREATE TABLE table_name_copy AS
SELECT * FROM (
SELECT *, (SELECT col_name FROM other_table WHERE other_table.col_id = table_name.col_id) as col_name
FROM table_name`
)
edit:
then run
ALTER TABLE table_name_copy DROP COLUMN <old column>
to remove the column you don't need any more