![]() While we are holding a row, other processes can update, select or delete the rows. If we are doing operations on the table, it will not affect the cursor directly.The cursor minimizes the load on the server as well as our network bandwidth.This cursor saves memory because the client and server did not need more memory to store the data results.This cursor will save time because we don’t need to wait for retrieving or processing the whole set of data.The main importance of the cursor in PostgreSQL retrieves a single record from the result set.Left join customer cust on emp.emp_id = cust.cust_id We have used the employee and customer table to join the table.ĬREATE OR REPLACE FUNCTION testing_trigger()Ĭur CURSOR FOR select * from employee emp.Below is the example of creating a cursor using the function in PostgreSQL.The open keyword is used to open a cursor in PostgreSQL. Now we're connected, and we can start using this database connection.Hadoop, Data Science, Statistics & othersĬreate or replace function (function name)ĭECLARE cursor_name (Any name given to cursor) ĬURSOR (keyword) for query (query to use in cursor)īelow is the example of declaring cursor in PostgreSQL.ĭECLARE test_cur CURSOR WITH HOLD FOR SELECT * FROM Employee ORDER BY emp_id I'll click the Create New Database Connection button. ![]() Once you have the credentials typed in, we can scroll on down. For more information on creating users, you can check out the PostgreS documentation. You'd want to instead head back to PostgreS or pgAdmin, create an Ignition user, and give them the capability to create tables and write queries within the Ignition database. In a production environment, I would not recommend you do this. For here, I'm going to use the PostgreS user that was first created when we installed PostgreS. We need to type in a username and password. As I pointed out, it was Ignition with capital I. This needs to match the database we created in the last video. We do have this little database parameter at the end here. I did use the default port for PostgreS during the installation, so I don't need to change that. Local host is technically fine here, but obviously we would replace that parameter with either another host name or IP address. In my case, the database is actually installed on the same server as my Ignition gateway. We just need to tell this configuration where the database is located. We need to play around with this Connect URL down here. For the description, we'll just type in a quick note. Now we're connected, and we can start using this database connection. ![]() Since I'm very creative, we'll just call it PostgreSQL.įor the description, we'll just type in a quick note. From here, I'll click on the Create new Database Connection link. We'll want to head over to databases and connections. I'm going to, in my browser, head over to My Gateway's Web interface. Now we're ready to connect our gateway to this Ignition database. In the previous lesson, we installed PostgreSQL, and we created this Ignition, with a capital I, database, using pgAdmin. In this lesson, we'll connect Ignition to a PostgreSQL Database. ![]()
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