DBOBuilder
Description
The DBOBuilder element represents a DataHandler service.
Might contain more DBOs that represent all the elementary DataHandler operations that can be combined in a service. These DBOs will be executed in order of definition. By default returns the output as a result of the last DBO. The output of a DBO can be used as input of the next.
The statements used in the DBOs may contain metadata resolved at runtime that allows you to customize the actual command to be sent to the database.
The properties of the GVBuffer object can be referenced with the metadata @{{name}}. The body of the GVBuffer object, if any, is passed to the processing engine or data transformation engine, or it will be populated with the service output.
The following table shows the parameters included into the DBOBuilder output GVBuffer containing statistics about the operations done:
Parameter | Description |
---|---|
REC_TOTAL | number of founded records |
REC_READ | number of read records |
REC_INSERT | number of inserted records |
REC_UPDATE | number of updated records |
REC_DISCARD | number of discarded records |
REC_DISCARD_CAUSE | Report about discarded records |
GreenVulcano® ESB configuration
The DBOBuilder element is used by dh-call and GVDataHandlerConfiguration.
The following table shows its attributes:
Attribute | Type | Description |
---|---|---|
type | fixed | This attribute must assume the value dbobuilder. |
class | fixed | This attribute must assume the value it.greenvulcano.gvesb.datahandling.dbobuilder.DBOBuilder |
name | required | Service name |
jdbc-connection-name | required | DataSource JNDI name |
transacted | optional | Defines if the services must be executed in transaction. Default true. |
isXA | optional | If the service is transacted, this attributes indicates if it participates in a distributed transaction or not. If false the DataHandler handle a local transaction. Default false |
output-data | optional | The default is the value of @output-data of the last DBOxxx; |
make-dump | optional | If set to none not perform the input/output data dump. If set to text or hex then the dump is performed as text or hexadecimal string. Default to text. |
The following example shows who to configure DBOBuilder combined with the retrievers (see RetrieverConfig) and the use of metadata inside the statement:
<?xml version="1.0" encoding="UTF-8"?>
<dh-call class="it.greenvulcano.gvesb.virtual.datahandler.DataHandlerCallOperation"
name="DataHandler" type="call">
<RetrieverConfig>
<GenericRetriever class="it.greenvulcano.gvesb.datahandling.utils.GenericRetriever" type="retriever">
<DataRetriever cacheable="true" method="getCityID" signature="NAME">
select ID from CITY where NAME='@{{NAME}}'
</DataRetriever>
<DataRetriever cacheable="true" method="getCityName" signature="ID">
select NAME from CITY where ID=@{{ID}}
</DataRetriever>
<DataRetriever>...
<DataRetriever>...
<DataRetriever>...
</GenericRetriever>
</RetrieverConfig>
<DBOBuilder class="it.greenvulcano.gvesb.datahandling.dbobuilder.DBOBuilder"
jdbc-connection-name="ds.gv_test" name="SearchPerson"
type="dbobuilder">
<DHVariables>
<DHVariable name="decimal-separator" value="."/>
<DHVariable name="grouping-separator" value=","/>
<DHVariable name="format" value="#0.00"/>
<DHVariable name="NAME" value="NULL"/>
<DHVariable name="CITY" value="NULL"/>
</DHVariables>
<DBOSelect class="it.greenvulcano.gvesb.datahandling.dbo.DBOSelect"
name="SearchPerson" transformation="SearchPerson" type="dbo">
<statement id="1" keys="1,2,3" type="select">
select p.NAME, p.BIRTHDATE, c.NAME, cc.CNUMBER, cc.CREDIT, cc.ENABLED
from PERSON p, CITY c, CREDIT_CARD cc
where p.ID_CITY = c.ID
and p.ID = cc.ID_OWNER
decode{{@{{NAME}}::NULL::::and p.NAME like '%@{{NAME}}%'}}
decode{{@{{CITY}}::NULL::::and c.NAME like '%@{{CITY}}%'}}
order by c.NAME, p.NAME</statement>
</DBOSelect>
</DBOBuilder>
<DBOBuilder .../>
<DBOBuilder .../>
</dh-call>
DBOBuilder has the following sub-element:
- DHAliasList: List of aliases for a given DataHandler service. It contains
- DHAlias: Alias for a DataHandler service with its Description
- DHVariables: List of default values for DataHandler service's variables. It contains
- DHVariable: Default value for DataHandler service's variable including the parameters
- Description
- name: variable name
- value: variable value
- DHVariable: Default value for DataHandler service's variable including the parameters
- XMLMerge: replace the old Merge element
DBOs
The DBO elements represent the elementary operations of DataHandler that can be combined in a service. Those are:
- DBOSelect
- DBOThreadSelect
- DBOUpdate
- DBOInsert
- DBOInsertOrUpdate
- DBOUpdateOrInsert
- DBOCallSP
- DBOFlatSelect
- DBOMultiFlatSelect
Inside of it you can include SQL statements which may contain metadata that will be resolved prior to execution.
You can also add more DHVariable elements that define default values for properties that may be missing in GVBuffer.