Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3829#discussion_r139525263
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/TableEnvironment.scala
---
@@ -502,23 +521,130 @@ abstract class TableEnvironment(val config:
TableConfig) {
* @param query The SQL query to evaluate.
* @return The result of the query as Table.
*/
+ @deprecated("use [[sqlQuery()]] instead")
def sql(query: String): Table = {
+ sqlQuery(query)
+ }
+
+ /**
+ * Evaluates a SQL Select query on registered tables and retrieves the
result as a
+ * [[Table]].
+ *
+ * All tables referenced by the query must be registered in the
TableEnvironment. But
+ * [[Table.toString]] will automatically register an unique table name
and return the
+ * table name. So it allows to call SQL directly on tables like this:
+ *
+ * {{{
+ * val table: Table = ...
+ * // the table is not registered to the table environment
+ * tEnv.sqlSelect(s"SELECT * FROM $table")
+ * }}}
+ *
+ * @param query The SQL query to evaluate.
+ * @return The result of the query as Table
+ */
+ def sqlQuery(query: String): Table = {
val planner = new FlinkPlannerImpl(getFrameworkConfig, getPlanner,
getTypeFactory)
// parse the sql query
val parsed = planner.parse(query)
- // validate the sql query
- val validated = planner.validate(parsed)
- // transform to a relational tree
- val relational = planner.rel(validated)
+ if (null != parsed && parsed.getKind.belongsTo(SqlKind.QUERY)) {
+ // validate the sql query
+ val validated = planner.validate(parsed)
+ // transform to a relational tree
+ val relational = planner.rel(validated)
+ new Table(this, LogicalRelNode(relational.rel))
+ } else {
+ throw new TableException(
+ "Unsupported SQL query! sqlQuery() only accepts SQL queries of
type SELECT, UNION, " +
+ "INTERSECT, EXCEPT, VALUES, WITH, ORDER_BY, and EXPLICIT_TABLE.")
+ }
+ }
+
+ /**
+ * Evaluates a SQL statement such as INSERT, UPDATE or DELETE; or a DDL
statement;
+ * Currently only SQL INSERT statement on registered tables are
supported.
+ *
+ * All tables referenced by the query must be registered in the
TableEnvironment. But
--- End diff --
Rephrase: "A [[Table]] is automatically registered when the
[[Table.toString()]] method is called, i.e., when it is embedded into a string.
Hence, SQL queries can directly reference a [[Table]] as follows: "
---
