Sql server® 2012 t-sql fundamentals

Predicates and Operators

T-SQL has language elements in which predicates can be specified—for example, query filters such as 

WHERE and HAVING, CHECK constraints, and others. Remember that predicates are logical expres-

sions that evaluate to TRUE, FALSE, or UNKNOWN. You can combine predicates by using logical opera-

tors such as AND and OR. You can also involve other types of operators, such as comparison operators, 

in your expressions.

Examples of predicates supported by T-SQL include IN, BETWEEN, and LIKE. The IN predicate al-

lows you to check whether a value, or scalar expression, is equal to at least one of the elements in a 

set. For example, the following query returns orders in which the order ID is equal to 10248, 10249, or 

10250.

SELECT orderid, empid, orderdate 

FROM Sales.Orders 

WHERE orderid IN(10248, 10249, 10250);

The BETWEEN predicate allows you to check whether a value is in a specified range, inclusive of 

the two specified boundary values. For example, the following query returns all orders in the inclusive 

range 10300 through 10310.

SELECT orderid, empid, orderdate 

FROM Sales.Orders 

WHERE orderid BETWEEN 10300 AND 10310;

The LIKE predicate allows you to check whether a character string value meets a specified pattern. 

For example, the following query returns employees whose last names start with D.

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