The SQL SELECT statement returns a result set of records from one or more tables.A SELECT statement retrieves zero or more rows from one or more database tables or database views. In most applications, SELECT is the most commonly used Data Manipulation Language command...
statement should only return rows where aggregate values meet the specified condition
Condition (SQL)
A relational database management system uses SQL conditions or expressions in WHERE clauses and in HAVING clauses to SELECT subsets of data.- Types of condition :...
s. It was added to the SQL language because the WHERE
Where (SQL)
A WHERE clause in SQL specifies that a SQL Data Manipulation Language statement should only affect rows that meet specified criteria. The criteria are expressed in the form of predicates...
keyword could not be used with aggregate functions.
Examples
To return a list of department IDs whose total sales exceeded $1000 on the date of January 1, 2000, along with the sum of their sales on that date:
SELECT DeptID, SUM(SaleAmount)
FROM Sales
WHERE SaleDate = '01-Jan-2000'
GROUP BY DeptID
HAVING SUM(SaleAmount) > 1000
An SQL join clause combines records from two or more tables in a database. It creates a set that can be saved as a table or used as is. A JOIN is a means for combining fields from two tables by using values common to each. ANSI standard SQL specifies four types of JOINs: INNER, OUTER, LEFT, and RIGHT...
example, the following query will return the list of departments who have more than 1 employee:
SELECT DepartmentName, COUNT(*)
FROM employee,department
WHERE employee.DepartmentID = department.DepartmentID
GROUP BY DepartmentName
HAVING COUNT(*)>1;
