Can I use CASE in FROM clause SQL?
No, you can’t pick a table to query using a CASE statement. CASE statements only go within expressions, such as for a column’s value or as part of your WHERE expression.
What is the use of WHERE clause in SQL?
The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition.
How can use multiple CASE statement in SQL Server?
Here are 3 different ways to apply a case statement using SQL:
- (1) For a single condition: CASE WHEN condition_1 THEN result_1 ELSE result_2 END AS new_field_name.
- (2) For multiple conditions using AND: CASE WHEN condition_1 AND condition_2 THEN result_1 ELSE result_2 END AS new_field_name.
What is the difference between where and having SQL clauses?
A HAVING clause is like a WHERE clause, but applies only to groups as a whole (that is, to the rows in the result set representing groups), whereas the WHERE clause applies to individual rows. A query can contain both a WHERE clause and a HAVING clause.
Can we use case statement in where clause in Oracle?
Introduction to Oracle CASE expression You can use a CASE expression in any statement or clause that accepts a valid expression. For example, you can use the CASE expression in statements such as SELECT , UPDATE , or DELETE , and in clauses like SELECT , WHERE , HAVING , and ORDDER BY .
How can use multiple case statement in SQL Server?
What is WHERE clause with example?
The SQL WHERE clause is used to specify a condition while fetching the data from a single table or by joining with multiple tables. If the given condition is satisfied, then only it returns a specific value from the table. You should use the WHERE clause to filter the records and fetching only the necessary records.
WHERE clauses can be used without?
We cannot use the HAVING clause without SELECT statement whereas the WHERE clause can be used with SELECT, UPDATE, DELETE, etc. WE can use aggregate functions like sum, min, max, avg, etc with the HAVING clause but they can never be used with WHERE clause.