Designing a Data Model and Building Data Objects for Customers in Software Attach barcode 39 in Software Designing a Data Model and Building Data Objects for Customers

Designing a Data Model and Building Data Objects for Customers generate, create 39 barcode none with software projects GS1 DataBar Family Types of attributes Using the T ype drop-down list control, we select the data type (that is, numerical, string, date, and so on) of the attribute to specify the kind of information that can be stored in the attribute. The following is the list of data types: . Integer 16, Integer 32, and Integer 64 data types are for storing signed integers. T he range of values that these types are able to store is as follows: Integer 16:-32,768 to 32, 767 Integer 32:-2,147,483,648 to 2,147,483,647 Integer 64:-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. type uses 3 Code 39 Full ASCII for None 2 bits for storing a value. The only limitation with these two data types is that they round off the values. To avoid any rounding of values, the Decimal data type is preferred.

The Decimal type uses fixed point numbers for storing values, so the numerical value stored in it is not rounded off. . String data type is used for storing text contents. Boolean data type is used for storing YES or NO values. Date data type is used for storing dates as well as timestamps.

Binary data type is used for storing binary data.. Decimal, Do barcode 39 for None uble, and Float data types are for storing fractional numbers. The Double data type uses 64 bits to store a value while the Float data. Transformab le data type works along with Value Transformers that help us create attributes based on any Objective-C class, that is, we can create custom data types other than the standard data types. This data type can be used to store an instance of UIColor, UIImage, and so on. It archives objects to instances of NSData.

We will learn more about it in detail in 9, Entering, Displaying, and the Deleting Stock.. Below the T Code 3 of 9 for None ype drop-down menu, we will see a few more fields in the detail pane, as shown in the next screenshot:. [ 84 ]. 4 . Fields applying constraints Min Length: Software Code 3 of 9 and Max Length: fields are for applying constraints of minimum and maximum number of characters to an attribute. If we exceed the range supplied in these fields, we get a validation error. Meaning, if we enter the string of fewer characters than the value supplied in Min Length: or the string has more characters than the value supplied in Max Length: field, this will result in a validation error while saving managed objects.

Reg. Ex: field stands for regular expression and is used for applying validation checks on the data entered in the attribute by making use of regular expressions. Default Value: field is for specifying default value of the attribute.

If we create a new managed object, the attribute will automatically be set to the default value specified in this field.. [ 85 ]. Designing a Data Model and Building Data Objects for Customers Let us add two more attributes to the Customer entity: emailid and contactno (for storing a customer"s e-mail address and contact number, respectively). These two attributes will also be of type: String as shown in the next screenshot. Now, save the .

xcdatamodel.. Building data objects for the Customer entity To build th e data objects (classes) for the entity defined in the data model, perform the following steps: 1. Click on the entity in Data Model Editor and then go to File . New File. Software Code-39 2. We get a dialog box to choose a template for the new file.

Select Cocoa Touch Class from under the iOS heading in the left pane and select the Managed Object Class template, as shown in the next screenshot followed by Next button. This template is visible only when the editing pane is currently showing a Core Data model and is the active pane..

[ 86 ]. 4 . 3. We get a dialog box that prompts for the location of generating managed object class, as shown in the following screenshot. The name of the subclass is based on the Entity name, so we will not be prompted to provide name for the subclass.

Keeping the values as default, let"s click on the Next button.. [ 87 ].
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