[SQL] Minor doc update: Add an example in DataFrameReader.schema

## What changes were proposed in this pull request? This patch adds a small example to the schema string definition of schema function. It isn't obvious how to use it, so an example would be useful. ## How was this patch tested? N/A - doc only. Author: Reynold Xin <[email protected]> Closes #20491 from rxin/schema-doc. (cherry picked from commit 3ff83ad) Signed-off-by: gatorsmile <[email protected]>
apache · Feb 3, 2018 · dcd0af4 · dcd0af4
1 parent 56eb9a3
commit dcd0af4
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala
@@ -74,6 +74,10 @@ class DataFrameReader private[sql](sparkSession: SparkSession) extends Logging {
    * infer the input schema automatically from data. By specifying the schema here, the underlying
    * data source can skip the schema inference step, and thus speed up data loading.
    *
+   * {{{
+   *   spark.read.schema("a INT, b STRING, c DOUBLE").csv("test.csv")
+   * }}}
+   *
    * @since 2.3.0
    */
   def schema(schemaString: String): DataFrameReader = {