how to declare in sql code example

Example 1: declare variable in stored procedure in sql server

DECLARE 
    @product_name VARCHAR(MAX),
    @list_price DECIMAL(10,2);

Example 2: how to declare a variable in sql

DECLARE @COURSE_ID AS INT, @COURSE_NAME VARCHAR (10);

Example 3: declare value in sql

DECLARE  { @LOCAL_VARIABLE[AS] data_type  [ = value ] }

Example 4: what does declare do in sql

-- MySQL

DECLARE variable_name datatype(size) [DEFAULT default_value];
-- Declaring a variable without specifying a default value will result it
-- in being a null value.
-- Declare is what allows us to create a variable