sjwiesman commented on a change in pull request #14975:
URL: https://github.com/apache/flink/pull/14975#discussion_r580600708
##########
File path: docs/content/docs/connectors/datastream/jdbc.md
##########
@@ -28,40 +28,119 @@ under the License.
This connector provides a sink that writes data to a JDBC database.
-To use it, add the following dependency to your project (along with your
JDBC-driver):
+To use it, add the following dependency to your project (along with your JDBC
driver):
{{< artifact flink-connector-jdbc withScalaVersion >}}
Note that the streaming connectors are currently __NOT__ part of the binary
distribution. See how to link with them for cluster execution [here]({{< ref
"docs/dev/datastream/project-configuration" >}}).
-Created JDBC sink provides at-least-once guarantee.
-Effectively exactly-once can be achieved using upsert statements or idempotent
updates.
-Example usage:
+## `JdbcSink.sink`
-```java
-StreamExecutionEnvironment env =
StreamExecutionEnvironment.getExecutionEnvironment();
-env
- .fromElements(...)
- .addSink(JdbcSink.sink(
- "insert into books (id, title, author, price, qty) values
(?,?,?,?,?)",
- (ps, t) -> {
- ps.setInt(1, t.id);
- ps.setString(2, t.title);
- ps.setString(3, t.author);
- ps.setDouble(4, t.price);
- ps.setInt(5, t.qty);
- },
- new JdbcConnectionOptions.JdbcConnectionOptionsBuilder()
- .withUrl(getDbMetadata().getUrl())
- .withDriverName(getDbMetadata().getDriverClass())
- .build()));
-env.execute();
+The JDBC sink provides at-least-once guarantee.
+Effectively though, exactly-once can be achieved by crafting upsert SQL
statements or idempotent SQL updates.
+Configuration goes as follow (see also [JdbcSink javadoc]({{
site.javadocs_baseurl
}}/api/java/org/apache/flink/connector/jdbc/JdbcSink.html)):
+
+```
+JdbcSink.sink(
+ sqlDmlStatement, // mandatory
+ jdbcStatementBuilder, // mandatory
+ jdbcExecutionOptions, // optional
+ jdbcConnectionOptions // mandatory
+)
+```
+
+### SQL DML statement and JDBC statement builder
+
+The sink builds one [JDBC prepared
statement](https://docs.oracle.com/en/java/javase/11/docs/api/java.sql/java/sql/PreparedStatement.html)
from a user-provider SQL string, e.g.:
+
+```
+INSERT INTO some_table field1, field2 values (?, ?)
+```
+
+It then repeatedly calls a user-provided function to update that prepared
statement with each value of the stream, e.g.:
+
+```
+(preparedStatement, someRecord) -> { ... update here the preparedStatement
with values from someRecord ... }
```
-Please refer to the [API documentation]({{ site.javadocs_baseurl
}}/api/java/org/apache/flink/connector/jdbc/JdbcSink.html) for more details.
+### JDBC execution options
+
+The SQL DML statements are executed in batches, which can optionally be
configured with the following instance (see also [JdbcExecutionOptions
javadoc]({{ site.javadocs_baseurl
}}/api/java/org/apache/flink/connector/jdbc/JdbcExecutionOptions.html))
+
+```
Review comment:
nit
```suggestion
```java
```
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