Question

Psycopg2 Python and PostgreSQL

If I am given a text file called test.txt that contains the name of various tables

*test.txt and its contents*

testTable

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Using Psycopg2 (Python and PostgreSQL), how would you read the text file and output the number of rows each table contains?

Answer 1

You can do this task as two parts.

Part 1 : Read the table names from file

Part 2 : find the row count in each table

code :

For part 1 : open the file and read the content to a variable:

f = open("test.txt")
data = f.read().split("\n")
f.close()

Now the variable data contains the list of table names.

Par2 : As you dosent specify the database name, I hope you had already made a connection to the database.

and let variable "conn" be the conncetion reference to the database.

Then create a cursor object using that conn variable

as

#Creating a cursor object using the cursor() method
cursor = conn.cursor()
for i in data:
  querry = "SELECT * from "+i
  #Retrieving data
  cursor.execute(querry)

  #Fetching all row from the table
  result = cursor.fetchall();
  print("The table named ",i," contains ",len(result), + " rows.")

#Closing the connection
conn.close()