CODEWITHSUNDEEP
sqlpython-3.xdatabasepostgresql
the man
the man

Reputation: 1391

How to ensure I don’t add duplicates rows to my database?

I’m currently feeding data from an API to my PostgreSQL database via SQLalchemy.

I run my script every night and append the new data to the relevant tables in the database.

Now, how do I ensure that I’m not adding duplicate rows to my database?

I’m currently using pandas and the pd.to_sql() method to create the tables and append the new data using the if_exists=“append” keyword in the pd.to_sql() method.

Upvotes: 1

Views: 311

Answers (1)

dsk
dsk

Reputation: 2003

You can use unique constraint in your table as below, the “Unique” constraint is a very powerful table-level constraint that you can apply to your table against a chosen table column, which can greatly assist to prevent duplicates in your data.

While creating a new table

USE TestDB;
GO
CREATE TABLE Users
 (
   UserID int NOT NULL  IDENTITY(1,1), 
   Name varchar(100) NOT NULL,
   Surname varchar(100) NOT NULL,
   EmailAddress varchar(100) NOT NULL,
   CONSTRAINT AK_UnqueEmail UNIQUE(EmailAddress) 
); 
GO

For existing Table

USE TestDB; 
GO
ALTER TABLE Users 
ADD CONSTRAINT AK_UniqueEmail UNIQUE (EmailAddress); 
GO

Upvotes: 1

Related Questions