I have two tables, table1 and table2, that have columns common to both.
The queries that obtain the column names of each table are given below,
Query to get columns from first table:
select column_name from information_schema.columns
where table_schema = 'schema1'
and table_name = 'table1';
Query to get columns from second table:
select column_name from information_schema.columns
where table_schema = 'schema2'
and table_name = 'table2';
I need to select data from table2, only the columns which are also in table1.
I do not have a postrgesql intace at the moment but Dynamic SQL is what you need.
The following query will get you the column names that appear in both table 1 and table 2.
select string_agg(column_name, ',') FROM (
select column_name from information_schema.columns
where table_schema = 'schema1'
and table_name = 'table1'
intersect
select column_name from information_schema.columns
where table_schema = 'schema2'
and table_name = 'table2'
)
And you need to build
EXECUTE 'select ' || select string_agg(column_name, ',') FROM (
select column_name from information_schema.columns
where table_schema = 'schema1'
and table_name = 'table1'
intersect
select column_name from information_schema.columns
where table_schema = 'schema2'
and table_name = 'table2'
) || ' from schema2.table2 '
Sory if there any syntax error as writing from mobile app, you can join both result set to get common data.
select column_name from information_schema.columns T2
JOIN (select column_name from information_schema.columns where table_schema = 'schema1' and table_name = 'table1') T1
ON T2.COLUMN_NAME = T1.COLUMN_NAME Where T2.table_schema = 'schema2' and T2.table_name = 'table2';
Related
i have built Join query on redshift, but it doesn't work. Do you know why?
select
table_schema,
table_name,
sizeMB,
tbl_rows
from
(
select
table_schema ,
table_name
from information_schema.columns
where column_name = 'abcdef' -- enter table name here
and table_schema = 'prev'
and table_name not like '%crfg%'
group by table_schema, table_name
) as a(table_schema, table_name)
join
(
select "table" as tablename, size as sizeMB, tbl_rows
from svv_table_info
where "schema" = 'prev'
group by "table", size , tbl_rows
) as b(tablename, sizeMB,tbl_rows)
on a.table_name = b.tablename
and it got Error: "Function "has_column_privilege(oid,smallint,text)" not supported."
Aim is to compare tables column_name with the views columns_name to check if they have the same columns , however, getting them with different orders. Wanted to see them both with same order
select t1.COLUMN_NAME, t2.COLUMN_NAME from
(select * from information_schema.columns where TABLE_SCHEMA = 'dmt' and table_name = '#tablename' ) as t1
left join
(select * from information_schema.columns where TABLE_SCHEMA = 'models' and table_name = 'viewName') as t2
on t1.ORDINAL_POSITION = t2.ORDINAL_POSITION
I want get the output like in the same order, for example:
Column_Name 1 Column_Name 2
cat cat
dog dog
You can use the following to get the comparison of the columns.
WITH ColumnsCTE (TABLE_NAME, COLUMN_NAME) AS
(
SELECT TABLE_NAME, COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'dmt' AND TABLE_NAME = 'TableName'
UNION ALL
SELECT TABLE_NAME, COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'models' AND TABLE_NAME = 'ViewName'
)
-- get the different columns of the tables / views.
SELECT t1.TABLE_NAME, t1.COLUMN_NAME AS [COLUMN_NAME 1], ISNULL(t2.COLUMN_NAME, 'missing on other table / view') AS [COLUMN_NAME 2]
FROM ColumnsCTE AS t1 LEFT JOIN ColumnsCTE AS t2 ON t1.COLUMN_NAME = t2.COLUMN_NAME AND t1.TABLE_NAME <> t2.TABLE_NAME
WHERE t2.COLUMN_NAME IS NULL
demo on dbfiddle.uk
You can't use the ORDINAL_POSITION to get the expected result since the order of the columns can be different. See the following example where the ORDINAL_POSITION is different but the columns are available in both tables / views:
CREATE TABLE Test (
id INT,
name VARCHAR(100)
);
CREATE VIEW ViewTest AS
SELECT name, id FROM Test;
If the order of the attributes is identitcal (you can hardcode which attributes to select and in which order)
i strongly recommend
"intersect" or "except" command
increddibly strong function offering almost anything you could wish for here.
I have two Tables which are, TS_SALES and TS_SALES_AUDIT.
Here TS_SALES is parent table and TS_SALES_AUDIT is child table.
when i count the columns in two tables using below code,
1) SELECT count(*) FROM user_tab_columns WHERE table_name = 'TS_SALES';
---------
Count(*)
---------
130
2) SELECT count(*) FROM user_tab_columns WHERE table_name = 'TS_SALES_AUDIT';
---------
Count(*)
---------
40
Can we return the column names which are not equal in both tables?
This should do the trick:
Columns that are in TS_SALES but not in TS_SALES_AUDIT
SELECT column_name FROM user_tab_columns WHERE table_name = 'TS_SALES'
minus
SELECT column_name FROM user_tab_columns WHERE table_name = 'TS_SALES_AUDIT'
Columns that are in TS_SALES_AUDIT but not in TS_SALES
SELECT column_name FROM user_tab_columns WHERE table_name = 'TS_SALES_AUDIT'
minus
SELECT column_name FROM user_tab_columns WHERE table_name = 'TS_SALES'
One method uses aggregation:
select max(table_name) as which_table_name,
max(column_name) as which_column_name
from user_tab_columns
where table_name in ('TS_SALES', 'TS_SALES_AUDIT')
group by column_name
having count(*) = 1;
To get the columns that exist in TS_SALES and not in TS_SALES_AUDIT, you can use the following query:
SELECT COLUMN_NAME FROM user_tab_columns
WHERE table_name = 'TS_SALES'
AND COLUMN_NAME NOT IN
(
SELECT COLUMN_NAME FROM user_tab_columns WHERE table_name = 'TS_SALES_AUDIT'
)
To achieve the reverse, use the following:
SELECT COLUMN_NAME FROM user_tab_columns
WHERE table_name = 'TS_SALES_AUDIT'
AND COLUMN_NAME NOT IN
(
SELECT COLUMN_NAME FROM user_tab_columns WHERE table_name = 'TS_SALES'
)
I am using the following SQL to grab index columns for a table:
SELECT DISTINCT COLUMN_NAME
FROM DBA_IND_COLUMNS
WHERE TABLE_NAME = 'MY_TABLE' AND TABLE_OWNER = 'SCHEMA'";
I want to adjust this SQL such that I grab the index columns and their data type:
SELECT DISTINCT COLUMN_NAME, DATA_TYPE
FROM DBA_IND_COLUMNS
WHERE TABLE_NAME = 'MY_TABLE' AND TABLE_OWNER = 'SCHEMA'";
But this gives an invalid identifier error for "DATA_TYPE". Is there a way to do this without creating another query?
You need to add DBA_TAB_COLUMNS to your query:
SELECT DISTINCT COL.COLUMN_NAME, COL.DATA_TYPE
FROM DBA_IND_COLUMNS IND
INNER JOIN DBA_TAB_COLUMNS COL
ON ( IND.TABLE_OWNER = COL.OWNER AND IND.TABLE_NAME = COL.TABLE_NAME AND IND.COLUMN_NAME = COL.COLUMN_NAME)
WHERE IND.TABLE_NAME = 'MY_TABLE' AND TABLE_OWNER = 'SCHEMA'
I want to select all the columns from two tables let us say Table A and Table B where A's Column Name is not equal to B's Column Name. I try to find a solution but all i find is how to get common columns.
select A.COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS A
join INFORMATION_SCHEMA.COLUMNS B
on A.COLUMN_NAME = B.COLUMN_NAME
where A.TABLE_NAME = 'table1'
and B.TABLE_NAME = 'table2'
I don't want all those columns to be appeared whose name is common, but want all other columns whose name is not same.
;WITH A AS(
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'table1'
),
B AS(
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'table2'
)
SELECT A.COLUMN_NAME FROM A
LEFT OUTER JOIN B
ON A.COLUMN_NAME = B.COLUMN_NAME
WHERE B.COLUMN_NAME IS NULL
UNION ALL
SELECT B.COLUMN_NAME FROM A
RIGHT OUTER JOIN B
ON A.COLUMN_NAME = B.COLUMN_NAME
WHERE A.COLUMN_NAME IS NULL
Use a correlated not exists in the where clause to get columns from Table1 that is not exist in Table2.
select A.COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS as A
where A.TABLE_NAME = 'Table1' and
not exists (
select *
from INFORMATION_SCHEMA.COLUMNS as B
where A.COLUMN_NAME = B.COLUMN_NAME and
B.TABLE_NAME = 'Table2'
)
To get the columns from both tables you can use the above query twice and combine the result with a union all.
select A.COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS as A
where A.TABLE_NAME = 'Table1' and
not exists (
select *
from INFORMATION_SCHEMA.COLUMNS as B
where A.COLUMN_NAME = B.COLUMN_NAME and
B.TABLE_NAME = 'Table2'
)
union all
select A.COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS as A
where A.TABLE_NAME = 'Table2' and
not exists (
select *
from INFORMATION_SCHEMA.COLUMNS as B
where A.COLUMN_NAME = B.COLUMN_NAME and
B.TABLE_NAME = 'Table1'
)
Or you can use except with union all.
select COLUMN_NAME
from (
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'Table1'
except
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS as A
where TABLE_NAME = 'Table2'
) as C
union all
select COLUMN_NAME
from (
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'Table2'
except
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS as A
where TABLE_NAME = 'Table1'
) as C