When I perform SELECT * FROM table I got results like below: 1 item1 data1 2 item1 data2 3 item2 data3 4 item3 data4 As you can see, there are dup records from column2 (item1 are …

Oct 15, 2012 · I want to get the unique values from the following list:

Apr 3, 2017 · uniqueId = df["Id"].unique() I get a list of unique IDs. How can I apply this filtering on the whole DataFrame such that it keeps the structure but that the duplicates (based on "Id") …

Mar 7, 2023 · How to do validation with database like unique filed validation in nest JS using the class validator? I created a custom validation class and tried it. But userService was undefined …

The OP is asking about whether it is possible to add an Attribute to an Entity class for a Unique Key. The short answer is that it IS possible, but not an out-of-the-box feature from the EF Core …

I have an array of numbers that I need to make sure are unique. I found the code snippet below on the Internet, and it works great until the array has a zero in it. I found this other script here on

In the table, one customer like John Smith can have multiple addresses. I need the SELECT query for this table to return only first row found where there are duplicates in 'CName'. For …

Mar 5, 2012 · Unique Key (UK): It's a column or a group of columns that can identify a uniqueness in a row. Primary Key (PK): It's also a column or group of columns that can identify a …

Apr 5, 2019 · SELECT DISTINCT my_col, count(*) OVER (PARTITION BY my_col ORDER BY my_col) AS num_rows FROM my_tbl Using this OVER based approach is of course optional. …

Mar 19, 2019 · I have a form where a user can add multiple select boxes for multiple cities. The problem is that each newly generated select box needs to have a unique id. Can this be done …