For more information, see the articles Access SQL: Use the WHERE clause to combine data sources Limit results by using criteria When you want to use data to limit the number of records that are returned in a query, you can use criteria.
The statement returns the maximum hourly rate for each job title in the HumanResources. GetContactInformation 5 ; F. In some situations, an expression is evaluated before a CASE expression receives the results of the expression as its input.
The CASE expression evaluates its conditions sequentially and stops with the first condition whose condition is satisfied. Query criteria are a type of expression. Use the WHERE clause to combine data sources Sometimes you may want to combine data sources based on fields that have matching data, but have different data types.
In the AdventureWorks database, all data related to people is stored in the Person. If a field is used with an aggregate function, you cannot specify criteria for that field in a WHERE clause.
Employee table is evaluated. If these expressions are equivalent, the expression in the THEN clause will be returned. Instead of looking at all the telephone numbers in your database, you could use a WHERE clause to limit the results and make it easier to find the telephone number that you want.
The simple CASE expression compares an expression to a set of simple expressions to determine the result. As the previous table illustrates, criteria can look very different from each other depending on the data type of the field to which the criteria apply and your specific requirements.
To combine data from two data sources based on values in fields that have different data types, you create a WHERE clause that uses one field as a criterion for the other field, by using the LIKE keyword. For example, the following query produces a divide by zero error when producing the value of the MAX aggregate.
For example, suppose that you want to use data from table1 and table2, but only when the data in field1 a text field in table1 matches the data in field2 a number field in table2. The function returns the first and last name of a given BusinessEntityID and the contact type for that person.
In the first example, the value in the SalariedFlag column of the HumanResources. Allows only an equality check. When subtracting 10 hours from VacationHours results in a negative value, VacationHours is increased by 40 hours; otherwise, VacationHours is increased by 20 hours.
For example, the person may be an employee, vendor representative, or a customer. Others are complex, and use functions and special operators, and include field references.
The following example displays the list price as a text comment based on the price range for a product. The HAVING clause restricts the titles to those that are held by men with a maximum pay rate greater than 40 dollars or women with a maximum pay rate greater than 42 dollars. CASE can be used in any statement or clause that allows a valid expression.
The CASE expression has two formats: For example, a field in one table may have a Number data type, and you want to compare that field to a field in another table that has a Text data type. Some criteria are simple, and use basic operators and constants. The following example uses the CASE expression to change the display of product line categories to make them more understandable.
Errors in evaluating these expressions are possible. Is Null This criterion can be applied to any kind of field to show records where the field value is null.
Both formats support an optional ELSE argument. You cannot create a join between fields that have different data types. It includes only those records where the Price or UnitsInStock field contains a value greater than 25 and less than The CASE expression cannot be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures.
This occurs prior to evaluating the CASE expression. Evaluates a list of conditions and returns one of multiple possible result expressions.
The following table shows some sample criteria and explains how they work.This SQL tutorial for data analysis covers using if/then logic with the SQL CASE statement. CASE can include multiple conditions and be used with aggregate functions. The SQL CASE statement. The CASE statement is SQL’s way of handling if/then logic.
It’s often helpful to write a query containing the CASE statement first and run it. Hello friends, I want to use select statement in a CASE inside procedure.
can I do it? of yes then how can i do it? following part of the procedure clears my requirement. Can you use case expressions in Access? I'm trying to determine the max date form 2 columns but keep getting syntax errors in the following code: CASE WHEN billsimas.comRVICEDATE >.
I trying to re-write this Microsoft Access IF statement as a CASE statement in SQL Server Status: IIf(IIf(B.[Online Class Completion Date] Is Null, Null. This is one of a set of articles about Access SQL. This article describes how to write a WHERE clause, and uses examples to illustrate various techniques that you can use in a.
CASE is the special scalar expression in SQL language. CASE expression is widely used to facilitate determining / setting a new value from user input values.
CASE expression can be used for various purposes which depends on the business logic. CASE expression is mostly used in SQL stored procedure.Download