sql and or | And OR Command in SQL - sql - sql tutorial - learn sql
- The SQL AND & OR operators are used to associate multiple conditions to narrow data in an SQL statement.
- These operators compare two conditions at a time to determine whether a row can be selected for the output.
- When retrieving data using a SELECT statement, you can use logical operators in the WHERE clause, which allows you to combine more than one condition.
Logical Operators | Description |
---|---|
OR | For the row to be selected at least one of the conditions must be true. |
AND | For a row to be selected all the specified conditions must be true. |
"OR" Logical Operator:
- If you want to select rows that satisfy at least one of the given conditions, you can use the logical operator, OR.
For example:
- if you want to find the names of students who are studying either Maths or Science, the query would be like,
SELECT first_name, last_name, subject
FROM student_details
WHERE subject = 'Maths' OR subject = 'Science'
- The output would be something like,
first_name | last_name | Subject |
---|---|---|
Anajali | Bhagwat | Maths |
Shekar | Gowda | Maths |
Rahul | Sharma | Science |
Stephen | Fleming | Science |
- The following table describes how logical "OR" operator selects a row.
Column1 |
Column2 |
Row Selected |
---|---|---|
YES | YES | YES |
YES | NO | YES |
NO | YES | YES |
NO | NO | NO |
Tags : sql tutorial , pl sql tutorial , mysql tutorial , oracle tutorial , learn sql , sql server tutorial"AND" Logical Operator:
"AND" Logical Operator:
- If you want to select rows that must satisfy all the given conditions, you can use the logical operator, AND.
For Example:
- To find the names of the students between the age 10 to 15 years, the query would be like:
SELECT first_name, last_name, age
FROM student_details
WHERE age >= 10 AND age <= 15;
- The output would be something like,
first_name | last_name | age |
---|---|---|
Rahul | Sharma | 10 |
Anajali | Bhagwat | 12 |
Shekar | Gowda | 15 |
- The following table describes how logical "AND" operator selects a row.
Column1 |
Column2 |
Row Selected |
---|---|---|
YES | YES | YES |
YES | NO | YES |
NO | YES | YES |
NO | NO | NO |
Interview questions for AND OR COMMAND in SQL:
- Which of the following SQL statement is valid? (There can be more than one answer
- a) SELECT First_Name AND Last_Name FROM Users;
- b) SELECT First_Name, Last_Name FROM Users WHERE Join_Date > 'Apr-01-2015' AND Birth_Date < 'Jan-01-1980';
- c) SELECT First_Name OR User_Name FROM Users;
- d) SELECT * FROM Users WHERE Last_Name = 'Brown' AND Gender = 'F';
- Answer: b),d)
- How many records will be returned by the following query?
SELECT * FROM Users WHERE Gender = 'M' AND Join_Date = 'Apr-09-2015';
Answer:
First |
Last |
Birth |
Gender | Join |
---|---|---|---|---|
Jamal | Santo | Oct-08-1983 | M | Apr-09-2015 |
Casey | Healy | Sep-20-1969 | M | Apr-09-2015 |
- How many records will be returned by the following query?
SELECT * FROM Users WHERE Gender = 'M' OR Join_Date = 'Apr-05-2015';
Answer:
- 4 records are returned. They are,
First_Name | Last_Name | Birth_Date | Gender | Join_Date |
---|---|---|---|---|
Sophie | Lee | Jan-05-1960 | F | Apr-05-2015 |
Richard | Brown | Jan-07-1975 | M | Apr-05-2015 |
Jamal | Santo | Oct-08-1983 | M | Apr-09-2015 |
Casey | Healy | Sep-20-1969 | M | Apr-09-2015 |