Posts (page 80)
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5 min readTo order a generated JSON column in PostgreSQL, you can use the ORDER BY clause along with the ->> operator to extract the value from the JSON column. For example, if you have a table with a JSON column called data and you want to order the rows based on a key within the JSON data, you can use a query like this: SELECT * FROM your_table ORDER BY data->>'key' DESC; This query will order the rows based on the value of the key key within the JSON data in descending order.
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4 min readTo change the animation speed of a element using jQuery, you can use the requestAnimationFrame method to control the frame rate of the animation. By adjusting the time increment in the requestAnimationFrame function, you can speed up or slow down the animation. Additionally, you can use jQuery's animate function to modify CSS properties that affect the speed or duration of the animation.
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5 min readTo share a PostgreSQL database with others, you will first need to ensure that the database is hosted on a server that is accessible to the users you want to share it with. This could be a local server within your organization or a cloud-based server.Once the database is set up and accessible, you can provide the necessary connection details to the users who need access. This typically includes the server address, port number, database name, and login credentials.
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7 min readTo place an image inside a square of canvas, you can follow these steps:Create a canvas element in your HTML file and specify its dimensions to be a square.Use CSS to style the canvas element and set its background color to white (or any color you prefer).Load your image using JavaScript by creating a new Image object and setting its src attribute to the URL of the image file.Once the image is loaded, use the drawImage() method of the canvas context to draw the image inside the square canvas.
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6 min readTo update an image in PostgreSQL using Python, you first need to establish a connection to the database using the psycopg2 library. Then you can use a SQL query to update the image data in the database. This query will typically involve specifying the table and columns to update, as well as the new image data to be inserted.You can read the image data from a file using Python's built-in file handling functions or by using a library like PIL (Python Imaging Library).
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4 min readTo keep drawing on canvas when scrolling, you can use JavaScript to track the scroll position and adjust the position of the drawing accordingly. You can store the scroll position in variables and update the drawing position based on the current scroll position. This way, the drawing will stay in place on the canvas even when the user scrolls the page. You can also use event listeners to listen for scroll events and update the drawing accordingly.
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5 min readTo create a trigger before insert in PostgreSQL, you first need to define the trigger function that will be executed before the insert operation. This function can contain any logic or operations you want to perform before the actual insertion of data into the table.Next, you need to use the CREATE TRIGGER statement to define the trigger and specify that it should be executed before an insert operation on the table.
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6 min readTo add a local image from your project folder in Canvas, you can use the createImage() function in p5.js. First, make sure the image file is located in the same directory as your sketch file. Then, use the preload() function to load the image before the sketch starts. Inside the preload() function, use the createImage() function to create a new image object and assign it to a variable. Use this variable to display the image on the canvas by calling the image() function in the draw() function.
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4 min readThe TRUNC() function in PostgreSQL is used to truncate a number to a specified number of decimal places. This function takes two arguments - the number to be truncated and the number of decimal places to retain.For example, if we have a number 5.6789 and we want to truncate it to 2 decimal places, we would use the TRUNC() function like this: SELECT TRUNC(5.6789, 2); This would return the value 5.67.
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4 min readTo make a canvas shape a circle in a drawing or painting, you can start by first drawing a circle with a pencil or chalk on the canvas. Use a compass to make a perfectly round circle if needed. Once you have the outline of the circle on the canvas, you can then begin to fill it in with paint or other materials of your choice. Pay attention to the edges of the circle to ensure they are smooth and even.
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7 min readTo create a fake PostgreSQL connection in Python, you can use the psycopg2 module and the fake2db library. First, you need to install the psycopg2 module by running pip install psycopg2 in your terminal. Next, install the fake2db library by running pip install fake2db.Then, you can create a fake PostgreSQL connection using the following steps:Import the necessary libraries: import psycopg2 from fake2db import connect Create a fake psycopg2.
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4 min readTo create a ctrl+z keyboard event in a canvas, you first need to add an event listener to the canvas element that listens for keydown events. Inside the event listener function, you can check if the combination of keys pressed is ctrl+z by checking if the event.ctrlKey and event.key properties match "z". If the condition is met, you can then write the logic to undo the last action in your canvas drawing.