11/26/2021

How To Create Cursor In Postgresql Example

Implicit cursor. It's almost always better to use the implicit cursor of a FOR loop than to resort to a somewhat slower and unwieldy explicit cursor. I have written thousands of plpgsql functions and only a hand full of times explicit cursors made any sense. To create a Postgres table in Python, we use the CREATE TABLE SQL statement. This query should be executed after establishing a connection to the database. We also create a cursor object by calling the cursor method that belongs to the connection object. Example: Returning a REF CURSOR from a procedure (PL/SQL) This example demonstrates how to define and open a REF CURSOR variable, and then pass it as a procedure parameter. The cursor variable is specified as an IN OUT parameter so that the result set is made available to the caller of the procedure.

  1. Postgresql Cursor Example
  2. Postgresql Cursor With Hold
  3. Postgresql Create Table Examples
  • Python PostgreSQL Tutorial
  • Python PostgreSQL Useful Resources
  • Selected Reading

The Cursor class of the psycopg library provide methods to execute the PostgreSQL commands in the database using python code.

Using the methods of it you can execute SQL statements, fetch data from the result sets, call procedures.

You can create Cursor object using the cursor() method of the Connection object/class.

Java

Example

Postgresql cursor for loop

Methods

Following are the various methods provided by the Cursor class/object.

Sr.No.Methods & Description
1

callproc()

This method is used to call existing procedures PostgreSQL database.

2

close()

This method is used to close the current cursor object.

3

executemany()

This method accepts a list series of parameters list. Prepares an MySQL query and executes it with all the parameters.

4

execute()

This method accepts a MySQL query as a parameter and executes the given query.

5

fetchall()

This method retrieves all the rows in the result set of a query and returns them as list of tuples. (If we execute this after retrieving few rows it returns the remaining ones)

6

fetchone()

This method fetches the next row in the result of a query and returns it as a tuple.

7

fetchmany()

This method is similar to the fetchone() but, it retrieves the next set of rows in the result set of a query, instead of a single row.

Postgresql Cursor Example

Properties

Postgresql Cursor With Hold

Following are the properties of the Cursor class −

Postgresql Create Table Examples

Sr.No.Property & Description
1

description

This is a read only property which returns the list containing the description of columns in a result-set.

2

lastrowid

This is a read only property, if there are any auto-incremented columns in the table, this returns the value generated for that column in the last INSERT or, UPDATE operation.

3

rowcount

This returns the number of rows returned/updated in case of SELECT and UPDATE operations.

4

closed

This property specifies whether a cursor is closed or not, if so it returns true, else false.

5

connection

This returns a reference to the connection object using which this cursor was created.

6

name

This property returns the name of the cursor.

7

scrollable

This property specifies whether a particular cursor is scrollable.