sql: how to copy from one table into another table - sql

table A's structure is a subset of table B, that means the table A's all the columns are the first columns of table B, but table B has more columns than table A. My question, what's the SQL statment to copy all the rows from table A to table B(the missing columns in table B will be kept empty).

Use:
INSERT INTO TABLE_B
SELECT col1,
col2,
col3,
NULL
FROM TABLE_A
Use NULL as the placeholder for however many columns you can't populate from TABLE_A, assuming TABLE_B columns allow NULL values.

Related

Insert into table sum of different columns with same schema

I´ve the following tables
I want to insert the sum of the columns [01],][02],[03]...etc. Into another table with the same schema, even if in a specific table exist only 1 record.
INSERT INTO TABLE1 VALUES AS SELECT * FROM
TABLE;
ALTER TABLE TABLE1
ADD COLUMN SUM_VALUES NUMBER(20)
DEFAULT( SUM(01,02,...N))
Is this what you are looking for or provide extra detail

Transpose row data to one column based on unique column identifier in SQL

This is a sample table I created in Excel. My desired output is in cell E7.
I wanted a transpose of all my rows in one single column based on the ID in column A. I tried the same in Excel with a VBA, but did not work as my dataset was large. Is there a way I can do this in SQL
Use UNION ALL :
SELECT id, col1 AS guid
FROM table t
UNION ALL
SELECT id, col2
FROM table t
UNION ALL
SELECT id, col3
FROM table t;

populate a table from another table including logging

I'm trying to populate a table from another table including logging.
For example there 2 tables A and B.
Data should be copied from B to A
There is one primary key called id in both tables.
The script should update the matching rows if existing.
The script should insert the missing rows from B if not found in table A
Data is expected to be around 800 k, having 15 columns.
I have no idea what you mean with "including logging", but to insert/update from one table to another, use merge:
merge into a
using b on (b.id = a.id)
when matched then update
set col1 = b.col1,
col2 = b.col2
when not matched then insert (id, col1, col2)
values (b.id, b.col1, col2);
This assumes the PK is named id in both tables.
merge into tableA a
using tableB b
on (a.id = b.id)
when matched then update set
--list columns here
when not matched then insert
--list columns to insert here
;
800k shouldn't be too much to insert in one transaction. If it is too much you should use cursor with bulk collect and split merge in a few steps passing to using only part of data. How big limit set for bulk collect you need to test which gives optimal times.

Insert null in one column on two columns same value in Oracle sql

i have inserted value from one table to another and i want to check if two columns values are same in a row insert null in one column of another table(table in which i am inserting values. In my example it is table1).
My existing query is given as follows how should i convert it according to my requirement.
INSERT INTO table1 (date1,date2)
SELECT substr(numtodsinterval(MAX(date1)-MIN(date2),'day'),
12,8)
FROM table2 where ....;

How to synchronize two tables in SSIS

I have a scenario where i need to synchronize two tables in SSIS
Table A is in DATABASE A and TABLE B is in DATABASE B. Both tables have same schema. I need to have a SSIS package that Synchronize TABLE A with TABLE B in Such a way That
1. It inserts all the records That Exist in Table A into Table B
AND
2. Update TABLE B if Same "Key" exsit in Both but Updated records in Table A
For Example Table A and B both Contains Key = 123 both Few Columns in Table A has been Updated.
I am thinking about using Merge Joins but that helps with only insertion of New records. How i can manage to implement UPDATE thing as well
1.It inserts all the records That Exist in Table A into Table B
Use a lookup transformation .Source will be Table A and Lookup will be Table B .Map the common columns in both the table and select those columns which you need for insertion.After lookup use OLEDB destination and the map the columns coming from the lookup and insert it into Table B
2.Update TABLE B if Same "Key" exsit in Both but Updated records in Table A
Same logic as above .Use lookup and instead of OLEDB Destination use OLEDB Command and then write the update sql .
Update TableB
Set col1=?,col2=?....
In the column mapping map the columns coming out of the lookup
Check out this article
Checking to see if a record exists and if so update else insert
Using Merge :
MERGE TableB b
USING TableA a
ON b.Key = a.Key
WHEN MATCHED AND b.Col1<>a.Col1 THEN
UPDATE
SET b.Col1 = a.Col1
WHEN NOT MATCHED BY TARGET THEN
INSERT (Col1, Col2, col3)
VALUES (a.Col1, a.Col2,a.Col3);
You can execute the Merge SQL in Execute SQL Task in Control Flow
Update : The Lookup transformation tries to perform an equi-join between values in the transformation input and values in the reference dataset.
You can just need to have one Data Flow Task .
Diagram
When the target table data does not have a matching value in the source table then lookup will redirect the target rows to the oledb destination which inserts the Data into source table( Lookup No Match Output)
When the target table rows matches for the business key with the source table then matched rows will be sent to the Oledb Command and using the Update SQL ,the all the target rows from the lookup will be updated in the source table .
This is just an overview .There is a problem with the above design as when the rows matches irrespective of any change in the columns the source table will be updated .So kindly refer the above article or try for search for SCD component in ssis
Update 2:
MERGE TableB b
USING TableA a
ON b.Key = a.Key
WHEN MATCHED THEN
UPDATE
SET b.Col1 = a.Col1
WHEN NOT MATCHED BY TARGET AND a.IsReady=1 THEN --isReady bit data type
INSERT (Col1, Col2, col3)
VALUES (a.Col1, a.Col2,a.Col3);