So I'm generating a pivot table using pandas. I'm using index Location Name, Customer ID and Customer Name (SortName).
When I pivot it's returning a row for each Customer Name per CustomerID. You can see that all the customer names are zero except for the customer name actually associated with the ID. When I filter there isn't any data for the customerID with the other names. Why is it doing this? I really only want it to group for unique combinations of the 3 indexes that have data.
I have two tables:
Product Table
ID (PK), Description, CategoryID, SegmentID, TypeID, SubTypeID, etc.
Attribute Table
ID (PK), ProductID (FK), Key, Value
And I would like to query these two tables in a join that returns 1 row for each product with all of the Key/Value pair records in the Attribute table returned in a single column, perhaps separated by a pipe character (Key1: Value1 | Key2: Value2 | Key3: Value3 | etc.). Each product could have a different number of key/value pairs, with some products have as few as 2-3 and some having as many as 30. I would like to figure out how to get the query results to look something like this (perhaps selected into a new table):
product.ID, product.Description, [special attributes column], product.CategoryID, product.SegmentID, etc.
example result:
65839, "WonderWidget", "HeightInInches: 26 | WeightInLbs: 5 | Color: Black", "Widgets", "Commerical"
Conversely, it would be helpful to figure out how to take the query results, formatted as mentioned above, and push them back into the original Attribute table. For example, if we output the query above into a table where the [special attributes column] was modified (values updated/corrected by a human), it would be nice to know how to use the table containing the [special attributes column] to update the original Attribute table. I think for that to be possible, the Attribute.ID field would need to be included in the query output.
In the end, what I am trying to accomplish is way to export the Product and Attribute data out to 1 row per product with all the attribute data so that it can be reviewed/updated/corrected by a human in something as simple as an Excel file, and then pushed back into SQL. I think I can figure out how to do all of that once I get over the hurdle of figuring out how to get the products and attributes out as one row per product. Perhaps the correct answer is to pivot all of the attributes into columns, but I'm afraid the query would be incredibly wide and wasteful. Open to suggestions for this as well. Changing to a document type database is not an option right now; need to figure out the best way to handle this in relational SQL.
You first need to group the Key value pairs. This can be achieved using a concat operatoor like ||, you need to think about nulls as well. NUll concatenated with NULL is still NULL in most DBs.
SELECT ProductID, Key || ':' || Value as KeyValue FROM AttributeTable
Then you would need to group those using an aggregating function like STRING_AGG (Assuming SQL Server above 2017). Other databases have different aggregate functions Mysql f ex uses GROUP_CONCAT
https://learn.microsoft.com/en-us/sql/t-sql/functions/string-agg-transact-sql?view=sql-server-2017
https://www.geeksforgeeks.org/mysql-group_concat-function/
SELECT ProductID, STRING_AGG( Key || ':' || Value, '|') as Key Value FROM AttributeTable GROUP BY ProductId
I can expand on the answer if you can provide more information.
I have a table in Snowflake with people's names and other attributes. To simplify, it looks like the table below.
How can I add a new column with assigned unique number to each person directly to the table using SQL?
The ideal result is like below
Use dense_rank():
select name, dense_rank() over (order by name) as uniquenum
from t;
You can use this logic in an update, but the exact syntax depends on the database.
I have an SQL table with product names in one column and a product category in another column. So each product belongs to a specific category. I am trying to figure out an sql command that will return distinct values from the product name column but will also display the product category each product belongs to. Any ideas?
You can try like this,
SELECT Distinct([ProductName]),[ProductCategeory] FROM [DB].[dbo].[tblProduct]
How can i generate an ID value for every set of duplicate records as seen in the second table with ID column? In other words, how can I let the first table to look like the second table using SQL query?
Assume that first name and last name in the first table can appear in duplicates.
Each first name and last name can have one or many purchase yr and cost.
The given image is just a sample. Total records in table 1 can reach thousands.
I'm using Oracle SQL.
Note: I'm working with one table only that is the first one. The second table is what I want.
You can use the DENSE_RANK analytic function to assign ID's as below:
EDIT:
Simplified query to generate ID's.
SELECT
DENSE_RANK() OVER (ORDER BY First_Name, Last_Name) ID,
t.*
FROM Table1 t;
Reference:
DENSE_RANK on Oracle Database SQL Reference