What can be used instead of or in sql
Alternatives to the or operator in SQL include: 1. UNION: merge query results and discard duplicate records; 2. IN: check whether the value is included in the specified list; 3. CASE WHEN: return different values based on conditions Value; 4. Subquery: Nested query to use the results of other queries.
Alternatives to or in SQL
In SQL queries, the or operator Used to combine two or more conditions to return records that match any one condition. However, in some cases, using or may be less efficient or difficult to read, so other alternatives may be used.
UNION
UNION operator combines the results of two or more queries, discarding duplicate records. It can be used to replace the or operator when we need to retrieve records matching specific criteria from multiple queries. The syntax is as follows:
SELECT ... FROM query1 UNION SELECT ... FROM query2;
IN
IN The operator checks whether the value is contained in the specified list. It can be used to replace the or operator when we need to check if a value matches multiple possible values. The syntax is as follows:
SELECT ... WHERE column IN (value1, value2, ...);
CASE WHEN
CASE WHEN statement allows us to perform different actions based on conditions. It can be used to replace the or operator when we need to return different values based on multiple conditions. The syntax is as follows:
SELECT CASE
WHEN condition1 THEN value1
WHEN condition2 THEN value2
...
ELSE valueN
END AS column_name;Subquery
A subquery is a query nested within another query. It can be used to replace the or operator when we need to use the results of other queries in the main query. The syntax is as follows:
SELECT ... FROM main_query WHERE condition IN (SELECT ... FROM subquery);
Example
Consider the following or operator query:
SELECT * FROM table WHERE name = 'John' OR age > 30;
We can use the following alternatives:
- UNION
SELECT * FROM table WHERE name = 'John' UNION SELECT * FROM table WHERE age > 30;
- IN
SELECT *
FROM table
WHERE name IN ('John', 'Mary')
OR age IN (30, 35);- CASE WHEN
SELECT *
FROM table
WHERE CASE
WHEN name = 'John' THEN TRUE
WHEN age > 30 THEN TRUE
ELSE FALSE
END;- Subquery
SELECT * FROM table WHERE name = (SELECT name FROM subquery WHERE age > 30);
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