Questions tagged [sql]
Structured Query Language (SQL) is a language for querying databases. Questions should include code examples, table structure, sample data, and a tag for the DBMS implementation (e.g. MySQL, PostgreSQL, Oracle, MS SQL Server, IBM DB2, etc.) being used.
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Hassle-free platform for a small data science team?
our team of 4 data scientists has been exploring options to automate our ETL, data storage and model updates and are looking for a hassle-free platform that can help with this.
We've had several ...
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SQL projects to do for a beginner [closed]
hey Guys i've just started learning sql, i've just finished a youtube course about sql and how to code, and i was wondering where can i find projects to do, so i can improve my skills
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How to get a SQL sequence value with sqlalchemy?
I would like to use a SELECT NEXT VALUE FOR to get a value from a sequence in Microsoft SQL Server. It does not look like I can simply use ...
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SQL BigQuery function to return the previous non null value
I have the following table where some of the values are null and I would like to fill them with the previous non-null values.
LAG function helps but if there are more than one null value in a row, it ...
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Formal terminology: metafeatures then groupby (GROUP BY) operation
In ML training and other analytics I often combine features to produce a 'metafeature' and then perform a 'groupby' (pandas) or 'GROUP BY' (SQL) query. What is the technical term for this operation?
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How to find own way in data field? [closed]
I need help finding my path in the data field. I just completed my MSc in Big Data at university. During my studies, I gained approximately Junior level Python and SQL programming skills, worked with ...
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How to programmatically manipulate SQL strings
As part of a hubby project I am working on, I need to be able to take SQL strings supplied by users, and then run it.
But before running it, i will like to do some manipulations to the SQL. For ...
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29
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Reduce dimension (Words) for recommender
I have made a related document finder natively in SQL Server.
Currently I use the word as dimensions.
Based on that i calculate the cosinus simularty to figure out related article. At the moment the ...
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Why two different series of SQL queries which do the same thing just in a different order have a different number of rows in their outputs?
I am working on a group project for the US Forest Service to create a dashboard on the US's arial firefighting operations and resources. This part is focused on creating a single data table for the ...
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When using sqldf for join in python, is there a format to be followed for column names inside sql query?
I'm trying to use sqldf to do a left join on python. Here's my code:
...
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How do I get a big-picture feel for my database?
Background: I was just granted access to my company's SQL Server (MS SQL 2019 via Azure Data Studio). As I have not yet been assigned any specific projects I want start digging.
I've asked my DBA to ...
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Why does PowerBI take longer to load data than PowerQuery takes to load preview?
I have a stored procedure in SQL Server and when I open PowerQuery, I can get a preview of the whole table in a minute or two. But once I click 'Apply and Close', it will take AGES to load and finally ...
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SQL, count total users' first order for each region, each day
I have a table called orders.
Link for the table here:
table
I want to get the total users' first order in each region, each day.
First, I tried to get the first order for each unique user by doing ...
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146
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Convert This Sql Query into Python pandas Code [closed]
Can help me to solve it with python pandas i don't need any help from python libraries i need code of python
Thx so much more for helping me
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Moving a Neural Network to the SQL in R
tl;dr
How do I use something like the tidypredict tool to move a neural network either textbook mlp, or deep, to SQL code?
Background:
This is an example that shows how to convert a linear model to ...
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How to read a table from MySQL work bench in colab
I have referred to various articles on Stack Overflow and external sources but somehow am unable to get answer for this. I would like to read a table from MySQL workbench database into a dataframe in ...
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How to generate test set with no data-leakage using multiple columns
I am developing a fraud detection algorithm. Among other things, my dataset contains the phone number, email address and a few other fields that should uniquely identify a user (let's call them "...
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Data engineering good and bad practice?
I'm a Data Analyst in a pretty big company and I'm having a really bad time with the data I'm being given. I spend about 70% of my time thinking about where to find the data and how to pull it instead ...
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Applied and view jobs ratio
I have the following data set where the column "kind" can be V(view) or A(apply), how can I do the following things given a particular job id how many applicant Apply (A) to that particular ...
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1
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30
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How to strategize model training with new data coming in every day?
I have a mysql database in which new records are added every day to raw data. This raw data is cleaned and a ML model is trained with it once a week. What should be the best strategy to capture new ...
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Join 2 columns from the same table into a new column but in seperate rows [closed]
I need to find customers that have multiple applications registered.
I have done a self join and used "WITH" to make it run faster but i also had to use OUTER APPLY STRING_SPLIT function as ...
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Using MySQL Common Table Expressions to solve the travelling salesman problem
The problem I'm trying to solve is very similar to the travelling salesman problem, where there are many paths between nodes in the database. I've tried to edit my example to fit into this well-known ...
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262
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Best way to store large amounts of time series data? Relational database (SQL) or NoSQL route. Also additional python/pandas question inside
so I'm working on a project and I'm sort of stuck as to how to store my data. I have a concept I want to propose but am unsure whether it is possible, if it is not I would appreciate any help ...
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74
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Creating a complex featureset for regression modeling
I am currently working a on project that requires me to convert all of the categorical variables to continuous (or binary) variables to build a regression model. The problem is that I have more than ...
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2
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How can I create a table from an existing table in SQL but using cells from the old table as columns in the new table? [closed]
I have a table,
and I want to create a new table such as the one below (from the table above)
In SQL, I tried using the following commands. I am able to generate a table with only one column like ...
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105
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Load data from SQL for Machine Learning
I have an SQL DB which has millions of records(10 years of data) and wanted to implement some ML Models. Most of the courses/tutorials explains using a local file or downloaded CSV. But in my case I ...
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120
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Create an amortization table with SQL [closed]
I have a list of credits, let's assume they are only two for ease:
Credit #1 and credit #2: One has 3 months of payments missing and the other has 6 months left of payments.
It would like to obtain a ...
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1
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43
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Optimization technique for iterative distribution
Apologies if this does not fit the proper format for this site, as it is a somewhat general question.
I have an application that sits on top of a SQL database, and need to handle a process which is ...
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1
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33
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query category wise dara
I have stored the some products and there respective category in sql.
Like this. Now I want fetch all product from table with respective category.
output should be=>
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1
answer
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How to change data source names in Google Data Studio
Google Data Studio has connectors to MySQL, PostgreSQL, etc. but these connections will come with default names.
Couldn't find out how to set the names for data sources in Google Data Studio. Is it ...
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Tools for a data science job [closed]
Could someone list out all the important tools and software required for a data science job? Example spark, tensorflow, SQL, tableau etc.
It would be helpful if you could list the domain and then 2 ...
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Hive Bring Table to Local Driver for Fast Debugging on CLI
I have a large Hive table on HDFS. Every time I query it, it runs a map reduce job which is slow.
For debugging my code on CLI, I want a fast query. Is it possible to sample rows of the table and ...
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1
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979
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Get the average time between first and 2nd call (postgresql)
I have the following data in table where I want to calculate the average time between 1st and 2nd call.
I know how to get the average, but I have a though time to figure out how to subtract the 2nd ...
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436
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Running a query in R after establishing dbconnect
I do not seem to figure out what is wrong it the following statement. The connection to the DWH is established but the query statement in R seems not to work, with the following error :
...
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Removing outliers with orders of magnitude differences
I have a dataset of virtual currency earn and spend events from a mobile game app. Unfortunately, people cheat in the game to get more currencies. These cheaters use different techniques so its quite ...
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Getting the earliest date (duplicates due to several call ids and agents)
I am trying to get the earliest call interaction, with only the agent that interacted at that call and the customer id. Using the following code, I still get duplicates:
...
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How important is advanced SQL for data science?
Is advanced level SQL required to be competitive as a data scientist? Is it more important for a data analyst to be good in SQL? Is it enough to be able to extract data using simple SQL queries?
I ...
user62049
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Storing and collecting data [closed]
I wanted to ask you which coding language I should use. I am pretty new to coding and could really use some help.
As I mentioned above I want to create a survey and afterward store my results in a ...
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1
answer
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Passing tuples (key, value) into parameterized SQL query in Python
NOTE: I am new to this community, so please let me know if I can help you help me!
I built a scraper in python that creates a tuple of (key, value).
I would like to pass both key and value as ...
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Are there decisive leaders in programming with tabular data?
What are the most effective bread-and-butter in-memory open source tabular data frameworks today? I have been working with tabular data for years with an in-house solution that integrates with Excel ...
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Getting transportation turnover as null when i filtered by Product nature [closed]
I am pretty new to SQL. When i tried the following query i am getting sum as 0.
Can somebody explain me the problem of the query.
...
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SQL Oracle - Excel's BETAINV function (Inverse cumulative function of a beta distribution) in SQL Oracle [closed]
Is there a function equal to Excel's BETAINV(probability,alpha,beta,[A],[B]) in Oracle SQL Developer? Or a similar one which I could use to return the inverse cumulative distribution function of a ...
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How to group by ID, and output without repeating IDs? [closed]
Input
UserID Profile
101 apple
102 banana
103 pie
101 banana
102 pine
103 berry
Output
...
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108
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Format of data in SQL for machine learning
I am a beginner at Machine Learning and am starting out on a ML project. I have a large chunk of the source material and have started extracting the data from it to be stored in SQL (initial test with ...
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Scraping mixed elements and passing to SQL
I'm running webscrapes via python which are retrieving data from csv's hosted on the web. I'd like to pass the data into a MSSQL database. An issue I have is the mixed elements/data types in the csv....
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1
answer
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How to plot time series data from SQLite database
I am trying to plot time series data by accessing the SQLite database. I successfully connect the database by coding the below script,however, i couldn't figure out how to plot the time series data ...
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205
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1
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157
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How to store subset of columns from a csv file?
I need to create a table in hive (or Impala) by reading from a csv file (named file.csv), ...
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242
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Self Union All in Tableau Public for Sankey Diagram
I'm following this 2017 YouTube tutorial from which I hope to learn Sankey diagrams.
At 2:28, he instructs us to select Convert to Custom SQL, after having opened ...
