[SPARK-44866][SQL] Add SnowflakeDialect to handle BOOLEAN type corr…

…ectly ### What changes were proposed in this pull request? In Snowflake a BOOLEAN data type exist but not the BIT data type. This PR adds `SnowflakeDialect` to override the default JdbcDialect and redefine the default mapping behaviour for the _boolean_ type. Currently, it's mapped to `BIT(1)` type. https://github.com/apache/spark/blob/a663c0bf0c5b104170c0612f37a0b0cdf75cd45b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JdbcUtils.scala#L149 ### Why are the changes needed? The BIT type does not exist in Snowflake. This cause the Spark Job to fail on table creation. ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? Unit test and directly on Snowflake Closes apache#42545 from hayssams/master. Authored-by: Hayssam Saleh <[email protected]> Signed-off-by: Dongjoon Hyun <[email protected]>
imback82 · Sep 8, 2023 · c8fa821 · c8fa821
1 parent a663c0b
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diff --git a/sql/core/src/main/scala/org/apache/spark/sql/jdbc/JdbcDialects.scala b/sql/core/src/main/scala/org/apache/spark/sql/jdbc/JdbcDialects.scala
@@ -702,6 +702,7 @@ object JdbcDialects {
   registerDialect(OracleDialect)
   registerDialect(TeradataDialect)
   registerDialect(H2Dialect)
+  registerDialect(SnowflakeDialect)
 
   /**
    * Fetch the JdbcDialect class corresponding to a given database url.

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/jdbc/SnowflakeDialect.scala b/sql/core/src/main/scala/org/apache/spark/sql/jdbc/SnowflakeDialect.scala
@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.jdbc
+
+import java.util.Locale
+
+import org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
+import org.apache.spark.sql.types.{BooleanType, DataType}
+
+private case object SnowflakeDialect extends JdbcDialect {
+  override def canHandle(url: String): Boolean =
+    url.toLowerCase(Locale.ROOT).startsWith("jdbc:snowflake")
+
+  override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
+    case BooleanType =>
+      // By default, BOOLEAN is mapped to BIT(1).
+      // but Snowflake does not have a BIT type. It uses BOOLEAN instead.
+      Some(JdbcType("BOOLEAN", java.sql.Types.BOOLEAN))
+    case _ => JdbcUtils.getCommonJDBCType(dt)
+  }
+}
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
@@ -2057,4 +2057,9 @@ class JDBCSuite extends QueryTest with SharedSparkSession {
     val df = sql("SELECT * FROM composite_name WHERE `last name` = 'smith'")
     assert(df.collect.toSet === Set(Row("smith", 1)))
   }
+
+  test("SPARK-44866: SnowflakeDialect BOOLEAN type mapping") {
+    val snowflakeDialect = JdbcDialects.get("jdbc:snowflake://account.snowflakecomputing.com")
+    assert(snowflakeDialect.getJDBCType(BooleanType).map(_.databaseTypeDefinition).get == "BOOLEAN")
+  }
 }