JDBC Component
The jdbc component enables you to access databases through JDBC, where SQL queries (SELECT) and operations (INSERT, UPDATE, etc) are sent in the message body. This component uses the standard JDBC API, unlike the SQL Component component, which uses spring-jdbc.
Maven users will need to add the following dependency to their pom.xml
for this component:
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<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jdbc</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> |
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This component can only be used to define producer endpoints, which means that you cannot use the JDBC component in a |
URI format
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jdbc:dataSourceName[?options] |
This component only supports producer endpoints.
You can append query options to the URI in the following format, ?option=value&option=value&...
Options
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Result
By default the result is returned in the OUT body as an ArrayList<HashMap<String, Object>>
. The List
object contains the list of rows and the Map
objects contain each row with the String
key as the column name. You can use the option outputType
to control the result.
Note: This component fetches ResultSetMetaData
to be able to return the column name as the key in the Map
.
Message Headers
Header | Description |
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| If the query is a |
| If the query is an |
| Camel 2.10: Rows that contains the generated keys. |
| Camel 2.10: The number of rows in the header that contains generated keys. |
| Camel 2.11.1: The column names from the ResultSet as a |
| Camel 2.12: A |
Generated keys
Available as of Camel 2.10
If you insert data using SQL INSERT, then the RDBMS may support auto generated keys. You can instruct the JDBC producer to return the generated keys in headers.
To do that set the header CamelRetrieveGeneratedKeys=true
. Then the generated keys will be provided as headers with the keys listed in the table above.
You can see more details in this unit test.
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Using generated keys does not work with together with named parameters. |
Using named parameters
Available as of Camel 2.12
In the given route below, we want to get all the projects from the projects table. Notice the SQL query has 2 named parameters, :?lic and :?min.
Camel will then lookup these parameters from the message headers. Notice in the example above we set two headers with constant value
for the named parameters:
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from("direct:projects") .setHeader("lic", constant("ASF")) .setHeader("min", constant(123)) .setBody("select * from projects where license = :?lic and id > :?min order by id") .to("jdbc:myDataSource?useHeadersAsParameters=true") |
You can also store the header values in a java.util.Map
and store the map on the headers with the key CamelJdbcParameters
.
Samples
In the following example, we fetch the rows from the customer table.
First we register our datasource in the Camel registry as testdb
:
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{snippet:id=register|lang=java|url=camel/trunk/components/camel-jdbc/src/test/java/org/apache/camel/component/jdbc/AbstractJdbcTestSupport.java} |
testdb
datasource that was bound in the previous step:Wiki Markup |
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{snippet:id=route|lang=java|url=camel/trunk/components/camel-jdbc/src/test/java/org/apache/camel/component/jdbc/JdbcRouteTest.java} |
DataSource
in Spring like this:Wiki Markup |
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{snippet:id=example|lang=java|url=camel/trunk/components/camel-jdbc/src/test/resources/org/apache/camel/component/jdbc/camelContext.xml} |
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{snippet:id=invoke|lang=java|url=camel/trunk/components/camel-jdbc/src/test/java/org/apache/camel/component/jdbc/JdbcRouteTest.java} |
In Camel 2.13.x or older
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{snippet:id=e1|lang=java|url=camel/trunk/components/camel-jdbc/src/test/java/org/apache/camel/component/jdbc/JdbcRouteSplitTest.java} |
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from("direct:hello") // here we split the data from the testdb into new messages one by one // so the mock endpoint will receive a message per row in the table // the StreamList option allows to stream the result of the query without creating a List of rows // and notice we also enable streaming mode on the splitter .to("jdbc:testdb?outputType=StreamList") .split(body()).streaming() .to("mock:result"); |
Sample - Polling the database every minute
If we want to poll a database using the JDBC component, we need to combine it with a polling scheduler such as the Timer or Quartz etc. In the following example, we retrieve data from the database every 60 seconds:
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from("timer://foo?period=60000").setBody(constant("select * from customer")).to("jdbc:testdb").to("activemq:queue:customers"); |
Sample - Move Data Between Data Sources
A common use case is to query for data, process it and move it to another data source (ETL operations). In the following example, we retrieve new customer records from the source table every hour, filter/transform them and move them to a destination table:
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from("timer://MoveNewCustomersEveryHour?period=3600000") .setBody(constant("select * from customer where create_time > (sysdate-1/24)")) .to("jdbc:testdb") .split(body()) .process(new MyCustomerProcessor()) //filter/transform results as needed .setBody(simple("insert into processed_customer values('${body[ID]}','${body[NAME]}')")) .to("jdbc:testdb"); |
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