Research on various properties of ADF series -1.eo

Source: Internet
Author: User

EO in the ADF can be seen as a Java representation of tables in a relational database.

1.Type

The type here is Java, and the type of database that needs to be mapped, there are some differences between the two, each mapping relationship is as follows:

Database column type BC Property Type Describe
VARCHAR2 Java.lang.String

VARCHAR2 reflected in
Java.lang.String

Number Java.math.BigDecimal Accuracy >8,
Number Java.lang.Integer
Number Java.lang.Long 1< accuracy <9
DATE Java.sql.Date
DATE Java.sql.Timestamp
TIMESTAMP Java.sql.Timestamp
Blob Oracle.jbo.domain.BlobDomain

Blobdomain Support
Streaming and lazy data loading

Clob Oracle.jbo.domain.ClobDomain

Clobdomain Support
Streaming and lazy data loading

2.Persistent

This property is selected by default when EO is generated from a table in the database. When this property is not selected (a temporary property, such as the source: Java code or Groove expression), the property is non-persisted.

However, temporary variables can also store property values in business logic.

3.Mandatory

This property tag is enforced, and entity validation is enforced. For example, drag the corresponding VO from one property to the JSFF page as follows, where the yellow part is the validation

            <Af:inputtextvalue= "#{bindings." Applyreasondesc.inputvalue} "label= "#{bindings." ApplyReasonDesc.hints.label} " required= "#{bindings. ApplyReasonDesc.hints.mandatory} " Columns= "$"rows= "3"readOnly= "true"MaximumLength= "#{bindings." ApplyReasonDesc.hints.precision} "Shortdesc= "#{bindings." ApplyReasonDesc.hints.tooltip} "ID= "It3">              <F:validatorbinding= "#{bindings." Applyreasondesc.validator} "/>            </Af:inputtext>

4.Change Indicator

This property checks for inconsistencies in the data. When the BC commits data changes to the database, the ADF verifies that the updates to the submitted data are updates that are not outdated. The execution logic is to execute a select query before the update to the database, comparing the original values in the EO with the values in the database.

5.Queriable

This is the query logical identity. When this value is true, the EO-based VO can use this property value.

6.History Column

If this property is selected, the drop-down box will appear: 1.created on: When to create; 2.modified on: When to modify; 3.created by: Creator; 4.modified by: last modified; 5.version number: corresponding version

When this attribute is checked, the data is automatically persisted to the database.

7.Updatable

There are three properties: 1.Always: Can update data to database permanently; 2.While NEW: Only when a new data is created; 3. Never: Cannot update

8.Refresh after

When new or changed data is submitted to the database, the database triggers have been manipulated, and EO is required to refresh the value after the most recent data submission for the database, so that EO can regain the latest data

However, this property can only be used when the Oracle database is

Research on various properties of ADF series -1.eo

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