Basic SQL

Question 1

Name 6 aggregate functions

Answer 1

COUNT()
SUM()
MAX()
MIN()
AVG()
ROUND()

Question 2

Whats the syntax for creating a primary key?

Answer 2

ALTER TABLE table
ADD CONSTRAINT constraintName
PRIMARY KEY (colName)

Question 3

Whats the syntax for creating a foreign key?

Answer 3

ALTER TABLE table1
ADD CONSTRAINT constraintName
FOREIGN KEY (foreignkey_table1_Name)
REFERENCES table2 (foreignkey_table2_Name);

Question 4

Whats the syntax for dropping a constraint?

Answer 4

ALTER TABLE tableName

DROP CONSTRAINT constraintName;

Question 5

How do you get the current date?

Answer 5

SYSDATE

Question 6

Whats the syntax for using the substr() function?

Answer 6

SUBSTR(string, startPosition, length)

Question 7

Whats the syntax for using the concat() function?

Answer 7

CONCAT(str1, str2)

Question 8

Whats the syntax for creating a table?

Answer 8

CREATE TABLE table_name (
column1 datatype,
column2 datatype
);

Question 9

Whats the syntax for inserting a row into a table?

Answer 9

INSERT INTO table_name

VALUES (value1, value2);

Question 10

Whats the syntax for deleting a row into a table?

Answer 10

DELETE FROM table_name WHERE condition;

Question 11

Whats the syntax for updating a row(s) in table?

Answer 11

UPDATE table_name
SET column = value
WHERE condition;