Channi Studies

Today I learned about DEFAULT constraint in MySQL!!!  W3Schools.comW3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.www.w3schools.com As you can guess from its name, DEFAULT constraint is used to set a default value for a colum. Let's start by checki..

In this post, we will learn about CHECK constraint used in MySQL. W3Schools.comW3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.www.w3schools.com CHECK constraint is used to limit the values that can be used in a column.  Let's start from our employe..

In this post, we will take a look at two constraints in MySQL—UNIQUE and NOT NULL. UNIQUEUNIQUE constraint ensures that all values in a column are different. We can add a constraint to a table when we create it, or after.  Let's make a new table named product, that stores three columns: id, name, and price of the product. Say we don't want any duplicative product id's in the table. We can use UN..

Let's starty by creating a temporary database for this post. CREATE DATABASE test( my_date DATE, my_time TIME, my_datetime DATETIME);SELECT * from test; To get current date, time, or date time, there are 3 built-in functions, CURRENT_DATE(), CURRENT_TIME, and NOW()Let's try inserting a new row of appropriate data obtained by these functions. INSERT INTO testVALUES (CURRENT_DATE(), CURR..