I have this newly created table in SQL Server with 3 columns ID, Name, Source.
Basically this table will be populated with data from other different tables, each specifically taking in their record IDs and record Names. I believe this can be easily achieved with an INSERT INTO SELECT statement.
I would like to find out on how to populate the Source column. This column is supposed to indicate which table the data came from. For example, Source in table A has 3 records, which I then copied the ID and Name columns from this table, and put it into my destination table.
At the same time, the 3 new records will have their Source column set, indicating it came from Table A. Then I will proceed to do the same for other tables.
You can use the constant string as follows:
INSERT INTO your_table
SELECT id, name, 'TableA' as source
FROM tableA
I am trying to replicate a VLOOKUP I have done in Excel in SSMS. I have two tables - table 1 is an application master listing, table 2 is an application listing. I want to simply verify that every column in table 1 has an identical match in table two. I also want to have my results populate with an inserted column, column B with the results.
I have already done a very straight forward VLOOKUP in Excel with a 1:1 match. I now have Col A with the application master listing names, and then the new lookup column B with the 1:1 match.
Does anyone know how to go about this in SQL?
I have a scenario as described below need to create a SSIS Package for that.
I have 3 COLUMNS in source table which needs to be entered in destination table.
But all these columns has to be looked up in the look up table of destination database and then enter their ID's in the destination column.
For example
Source table has 3 columns with values
idnum static type timedimension geography modified date
1 price daydate france 8/12/2015
2 RetailpRICE WEEK ITALY 9/12/2014
I want a package which looks up the column values with the matchin ID and populates in the destination table...
I know we can use the LOOKUP transform to update the data for one single column in destination table what about the other columns which I need to insert along with the lookup insertion.
How can I achieve this ? Also is there a way to pull only the recent data from the source table using modified date column values
Use a different lookup for each lookup table that you need to reference to get the Ids. So if each of your columns that you want IDs for gets its ID from a different table, then you need to use three lookups, one after the other, until you have all three IDs.
I have a table with 32 Million rows and 31 columns in PostgreSQL 9.2.10. I am altering the table by adding columns with updated values.
For example, if the initial table is:
id initial_color
-- -------------
1 blue
2 red
3 yellow
I am modifying the table so that the result is:
id initial_color modified_color
-- ------------- --------------
1 blue blue_green
2 red red_orange
3 yellow yellow_brown
I have code that will read the initial_color column and update the value.
Given that my table has 32 million rows and that I have to apply this procedure on five of the 31 columns, what is the most efficient way to do this? My present choices are:
Copy the column and update the rows in the new column
Create an empty column and insert new values
I could do either option with one column at a time or with all five at once. The columns types are either character varying or character.
The columns types are either character varying or character.
Don't use character, that's a misunderstanding. varchar is ok, but I would suggest just text for arbitrary character data.
Any downsides of using data type "text" for storing strings?
Given that my table has 32 million rows and that I have to apply this
procedure on five of the 31 columns, what is the most efficient way to do this?
If you don't have objects (views, foreign keys, functions) depending on the existing table, the most efficient way is create a new table. Something like this ( details depend on the details of your installation):
BEGIN;
LOCK TABLE tbl_org IN SHARE MODE; -- to prevent concurrent writes
CREATE TABLE tbl_new (LIKE tbl_org INCLUDING STORAGE INCLUDING COMMENTS);
ALTER tbl_new ADD COLUMN modified_color text
, ADD COLUMN modified_something text;
-- , etc
INSERT INTO tbl_new (<all columns in order here>)
SELECT <all columns in order here>
, myfunction(initial_color) AS modified_color -- etc
FROM tbl_org;
-- ORDER BY tbl_id; -- optionally order rows while being at it.
-- Add constraints and indexes like in the original table here
DROP tbl_org;
ALTER tbl_new RENAME TO tbl_org;
COMMIT;
If you have depending objects, you need to do more.
Either was, be sure to add all five at once. If you update each in a separate query you write another row version each time due to the MVCC model of Postgres.
Related cases with more details, links and explanation:
Updating database rows without locking the table in PostgreSQL 9.2
Best way to populate a new column in a large table?
Optimizing bulk update performance in PostgreSQL
While creating a new table you might also order columns in an optimized fashion:
Calculating and saving space in PostgreSQL
Maybe I'm misreading the question, but as far as I know, you have 2 possibilities for creating a table with the extra columns:
CREATE TABLE
This would create a new table and filling could be done using
CREATE TABLE .. AS SELECT.. for filling with creation or
using a separate INSERT...SELECT... later on
Both variants are not what you seem to want to do, as you stated solution without listing all the fields.
Also this would require all data (plus the new fields) to be copied.
ALTER TABLE...ADD ...
This creates the new columns. As I'm not aware of any possibility to reference existing column values, you will need an additional UPDATE ..SET... for filling in values.
So, I' not seeing any way to realize a procedure that follows your choice 1.
Nevertheless, copying the (column) data just to overwrite them in a second step would be suboptimal in any case. Altering a table adding new columns is doing minimal I/O. From this, even if there would be a possibility to execute your choice 1, following choice 2 promises better performance by factors.
Thus, do 2 statements one ALTER TABLE adding all your new columns in on go and then an UPDATE providing the new values for these columns will achieve what you want.
create new column (modified colour), it will have a value of NULL or blank on all records,
run an update statement, assuming your table name is 'Table'.
update table
set modified_color = 'blue_green'
where initial_color = 'blue'
if I am correct this can also work like this
update table set modified_color = 'blue_green' where initial_color = 'blue';
update table set modified_color = 'red_orange' where initial_color = 'red';
update table set modified_color = 'yellow_brown' where initial_color = 'yellow';
once you have done this you can do another update (assuming you have another column that I will call modified_color1)
update table set 'modified_color1'= 'modified_color'
Below i have a table where i need to get fields from one column to three columns.
This is how i would like the data to end up
Column1
Music
Column2
com.sec.android.app.music
Column3
com.sec.android.app.music.MusicActionTabActivity
Give the table a numeric autonumber id
Remove the rows with no data with a select where blank spaces or null
Find records with no point in the content with a select
Use the previous query as a source and use the id to find the id + 1 to find the next record and do the same with + 2 to find the second row
Build a table to hold the new structure and use the query as a source to insert the new created data in the new table with the 3 columns structure.
This is an example using sql server
Test table design
Data in table
Query
Look at the query from the inside. The first query inside clean the null records. Then the second query find the records with out point. This records are the reference to find the related two records. Then the id of the records with out point are used to make a query in the select adding 1 for the next record and then other query adding 2 to find the other record. Now you only need to create a table to insert this data, using this query as the source.