Building Queries in Microsoft Access 2007

Transcription

1 Building Queries in Microsoft Access 2007 Description In this class we will explore the purpose, types and uses of Queries. Learn to design a query to retrieve specific data using criteria and operators. Audience This class is appropriate for anyone new to using Microsoft Access in general and seasoned users of Access, but new to the 2007 version. Objectives After completing this workshop, you should be able to: Create different types of queries. Filter data Create expressions for filtering criteria in a query. Prerequisites Basic computer skills (PC) Queries Queries are the "potatoes" of Access. Queries go hand-in-hand with the table. While all queries are ultimately built upon the tables, they give Access real power. Crreatte a Sellectt Querry Select the Create tab Select the Query Design icon 1 Page

2 The Show Table window appears. You may choose a Record Source from Tables, Queries (or Both). Select the Record Source by either double click on it, or highlighting it and Press the Add button When finished selected the source(s): Press the Close button The record source will show above the Query by Example grid: (QBE grid) Select the Fields to include in the query Double-Click 2 Page

3 Now Run! The Query to view the data To return to the Design view: Select the View icon Press the Save button Name the Query Press the OK button Add Crriitterriia Fill in the Criteria meeting the value for the particular field you are seeking. Now Run! The Query to view the data If the Query returns the data you are seeking: Press the Save button 3 Page

4 Common Operrattorrs fforr Crriitterriia Is Null or Is Not Null Operator Purpose Example Determines whether a value is Field1 Is Not Null Null or Not Null. Like "pattern" Matches string values by using the wildcard operators? and *. Field1 Like "instruct*" Between val1 And val2 Determines whether a numeric or date value is found within a range. Field1 Between 1 And 10 - OR - Field1 Between # # And # # < Returns True if the first value is less than the second value. <= Returns True if the first value is less than or equal to the second value. > Returns True if the first value is greater than the second value. >= Returns True if the first value is greater than or equal to the second value. = Returns True if the first value is equal to the second value. <> Returns True if the first value is not equal to the second value. Value1 < Value2 Value1 <= Value2 Value1 > Value2 Value1 >= Value2 Value1 = Value2 Value1 <> Value2 4 Page

5 Crreatte a Callcullattiing Querry Create a Select Query. In a blank column on the Field line of the QBE grid Type the Calculation: This example is calculating the difference between (DateDiff) date in the [BirthDate] column and today's date (Date()) Age: DateDiff("yyyy",[BirthDate],Date()) This example is calculating the [Quantity] Field multiplied by the [UnitPrice] Amount: [Quantity] * [UnitPrice] When finished with the calculating field - Run! The Query to view the data If the Query returns the data you are seeking: Press the Save button Here are some other common operators used for calculations: Operator Purpose Example + Sum two numbers. [Subtotal]+[SalesTax] - Find the difference between two numbers or [Price]-[Discount] indicate the negative value of a number. * Multiply two numbers. [Quantity]*[Price] / Divide the first number by the second number. [Total]/[ItemCount] \ Round both numbers to integers, divide the first number by the second number, and then truncate the result to an integer. Mod Divide the first number by the second number, and then return only the remainder. [Registered]\[Rooms] [Registered] Mod [Rooms] 5 Page

6 Crreatte a Parrametterr Querry Create a Select Query. In the Criteria row of a field for which you want a parameter applied: Type the text that you want the parameter dialog box to display enclosed in Square Brackets Example [Enter City] Now Run! The Query to view the data You can also use an expression with your parameter prompts, for example: Between [Start Date] And [End Date] 6 Page