Question

Please help me and explain this table clearly. it is created from rice ricipes

TABLE 3: Ingredient

           CREATE TABLE ingredient(

ingredient_ID serial PRIMARY KEY,

process_ID INTEGER NOT NULL,

step varchar(50) NOT NULL,

ingredient_name VARCHAR(50) NOT NULL,

ingredient_amount SMALLINT NOT NULL);

Answer 1

ANSWER: Here you are creating a table name as Ingredient by the sql statement create , Here first column ingredient_ID has data type as serial which stores a sequential integer, of the INT data type, that is automatically assigned by the database server when a new row is inserted. as given in the below insert statements I do not inserted a value for column ingredient_ID but it is showing in the table and we should note here that ingredient_ID is also a primary key which will be unique always . Now next column is process_ID which is integer you can insert only integer value in this column and int the next column step which is of varchar type you can insert any value in this column , next column is ingredient_name which is also varchar type here also you can insert any value and the last column is ingredient_amount which is of SMALL INT type here you can insert the int values int the range of -2¹⁵ (-32,768) to 2¹⁵-1 (32,767). Below some scripts and snapshot is given for better understanding.

INSERT STATEMENTS:

insert into ingredient (process_ID,step, ingredient_name,ingredient_amount) values ('1','one','rice','2');

insert into ingredient (process_ID,step, ingredient_name,ingredient_amount) values ('2','two','water','1');

SELECT *FROM ingredient;

SELECT * FROM ingredient; Edit the SQL Statement, and click "Run SQL" to see the result. Run SQL >> Result: Number of Records: 3 ingredient_ID process_ID step ingredient_name ingredient_amount one rice two water