[SPARK-12747][SQL] Use correct type name for Postgres JDBC's real array

https://issues.apache.org/jira/browse/SPARK-12747

Postgres JDBC driver uses "FLOAT4" or "FLOAT8" not "real".

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #10695 from viirya/fix-postgres-jdbc.

2 files changed, 4 insertions, 0 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/jdbc/PostgresDialect.scala b/sql/core/src/main/scala/org/apache/spark/sql/jdbc/PostgresDialect.scala
index ad9e31690b..8d43966480 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/jdbc/PostgresDialect.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/jdbc/PostgresDialect.scala
@@ -60,6 +60,8 @@ private object PostgresDialect extends JdbcDialect {
     case StringType => Some(JdbcType("TEXT", Types.CHAR))
     case BinaryType => Some(JdbcType("BYTEA", Types.BINARY))
     case BooleanType => Some(JdbcType("BOOLEAN", Types.BOOLEAN))
+    case FloatType => Some(JdbcType("FLOAT4", Types.FLOAT))
+    case DoubleType => Some(JdbcType("FLOAT8", Types.DOUBLE))
     case ArrayType(et, _) if et.isInstanceOf[AtomicType] =>
       getJDBCType(et).map(_.databaseTypeDefinition)
         .orElse(JdbcUtils.getCommonJDBCType(et).map(_.databaseTypeDefinition))
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala
index 1fa22e2933..518607543b 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala
@@ -514,6 +514,8 @@ class JDBCSuite extends SparkFunSuite
     val Postgres = JdbcDialects.get("jdbc:postgresql://127.0.0.1/db")
     assert(Postgres.getCatalystType(java.sql.Types.OTHER, "json", 1, null) === Some(StringType))
     assert(Postgres.getCatalystType(java.sql.Types.OTHER, "jsonb", 1, null) === Some(StringType))
+    assert(Postgres.getJDBCType(FloatType).map(_.databaseTypeDefinition).get == "FLOAT4")
+    assert(Postgres.getJDBCType(DoubleType).map(_.databaseTypeDefinition).get == "FLOAT8")
     val errMsg = intercept[IllegalArgumentException] {
       Postgres.getJDBCType(ByteType)
     }