In SQL, The "UPDATE" statement is used to modify existing records in a table.
UPDATE Statement allows us to change the values of one or more columns in one or more rows from the table in the database based on specified conditions.
UPDATE tableName SET columnName1 = value1, columnName2 = value2 WHERE condition;
tableName: The name of the table you want to update.
SET: Specify the columns you want to update along with their new values.
WHERE: Optional, specifies the condition that must be satisfied for the update to occur. If you omit the WHERE clause, all records in the table will be updated.
In the below example, we have applied conditions for ex:- "product_code = `A101`" to filter from the table and update it's `product_price` to `2000`.
UPDATE products SET product_price = 2000 WHERE product_code = "A101";
Above UPDATE Command will make a change to the unique record in the table whose `product_code` column value is equal to "A101" in the table.
In the below example, update the product_price to `2000` of all products of the Electronic category.
UPDATE products SET product_price = 2000 WHERE category = 'Electronic';
Above UPDATE Command will make changes to selective types of records in a single operation.
In this example, updates the `grade` and `status` columns for students who scored `90 or above`.
UPDATE students SET grade = 'A', status = 'Pass' WHERE score >= 90;
Above UPDATE Command will make changes to multiple records in a single operation.
If we opt-out `WHERE` Clause from the `UPDATE` Statement from the query, then it will update all records in the table.
UPDATE products SET product_quantity = 100;
The above command will update all records in the table with `product_quantity` set to `100`.
Be cautious while using the `UPDATE` statement, especially without opting out of the `WHERE` clause, as it can modify a large number of records unintentionally.