In SQL, the AND and OR operators are used to combine multiple conditions in a WHERE clause to filter rows from a database table. They control the logical relationships between these conditions.
Here's an explanation of the differences between AND and OR operators:
AND Operator:
Logical AND: The
ANDoperator is a logical operator that requires all specified conditions to be true for a row to be included in the result set. In other words, it creates a more restrictive filter.Example: If you use the
ANDoperator to combine two conditions, Condition A and Condition B, the result will only include rows that satisfy both Condition A and Condition B.SELECT * FROM table_name WHERE Condition_A AND Condition_B;The row must meet both Condition A and Condition B to be selected.
Truth Table: The result of the
ANDoperator is true only when both of its operands are true. The truth table forANDis as follows:true AND true=> truetrue AND false=> falsefalse AND true=> falsefalse AND false=> false
OR Operator:
Logical OR: The
ORoperator is a logical operator that requires at least one of the specified conditions to be true for a row to be included in the result set. In other words, it creates a less restrictive filter.Example: If you use the
ORoperator to combine two conditions, Condition A and Condition B, the result will include rows that satisfy either Condition A or Condition B or both.SELECT * FROM table_name WHERE Condition_A OR Condition_B;The row can meet either Condition A or Condition B to be selected.
Truth Table: The result of the
ORoperator is true if at least one of its operands is true. The truth table forORis as follows:true OR true=> truetrue OR false=> truefalse OR true=> truefalse OR false=> false
Usage:
- Use
ANDwhen you want to create a more restrictive condition where all specified criteria must be met. - Use
ORwhen you want a less restrictive condition and you're interested in rows that meet any of the specified criteria.
Here's an example to illustrate the difference:
SELECT *
FROM products
WHERE (category = 'Electronics' AND price > 100)
OR (category = 'Clothing' AND color = 'Red');
This SQL statement selects products that are either in the 'Electronics' category and have a price over 100 or are in the 'Clothing' category and are red in color, showing the use of both AND and OR operators together.
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