Question

Suman has created a table named WORKER with a set of records to maintain the data of the construction sites, which consists of WID, WNAME, WAGE, HOURS, TYPE, and SITEID. After creating the table, she entered data in it, which is as follows:

WID	WNAME	WAGE	HOURS	TYPE	SITEID
W01	Ahmed J	1500	200	Unskilled	103
W11	Naveen S	520	100	Skilled	101
W02	Jacob B	780	95	Unskilled	101
W15	Nihal K	560	110	Semiskilled	NULL
W10	Anju S	1200	130	Skilled	103

Based on the data given above, answer the following questions:

1. Write the SQL statement to display the names and wages of those workers whose wages are between 800 and 1500.
2. Write the SQL statement to display the record of workers whose SITEID is not known.
3. Write the SQL statement to display WNAME, WAGE and HOURS of all those workers whose TYPE is ‘Skilled’.
4. Write the SQL statement to change the WAGE to 1200 of the workers where the TYPE “Semiskilled”.

Answer 1

1. Select WNAME, WAGE from WORKER where WAGE Between 800 and 1500;

2. Select * from WORKER where SITEID IS NULL;

3. Select WName, Wage, Hours from WORKER where Type="Skilled";

4. Update Worker Set Wage=1200 where Type="SemiSkilled";