constraints

Handling Null Values in SQL Databases In SQL databases, it is important to properly handle null values, which are empty or missing data. Here are some tips on how to handle null values effectively. When creating a table, you can define constraints to prevent null values. For example, let’s say we have a table called “people” with columns for age and name: CREATE TABLE people ( age INT NOT NULL, name CHAR(20) NOT NULL ); By adding the NOT NULL constraint to the column definitions, we ensure that both age and name cannot be null....

Learn how to use getUserMedia() to access audio and video input from the user. The getUserMedia() method is available through the MediaDevices object exposed by navigator.mediaDevices. Warning: Although the navigator object still exposes a deprecated getUserMedia() method, it is recommended to use getUserMedia() through the mediaDevices object for consistency. Here’s how you can use the getUserMedia() method: Assume we have a button: <button>Start streaming</button> We wait for the user to click this button and then call the navigator....