org.apache.spark.sql.jdbc

Class DriverQuirks

Object

org.apache.spark.sql.jdbc.DriverQuirks

Direct Known Subclasses:

MySQLQuirks, NoQuirks, PostgresQuirks

public abstract class DriverQuirks
extends Object

Encapsulates workarounds for the extensions, quirks, and bugs in various databases. Lots of databases define types that aren't explicitly supported by the JDBC spec. Some JDBC drivers also report inaccurate information---for instance, BIT(n>1) being reported as a BIT type is quite common, even though BIT in JDBC is meant for single-bit values. Also, there does not appear to be a standard name for an unbounded string or binary type; we use BLOB and CLOB by default but override with database-specific alternatives when these are absent or do not behave correctly.

Currently, the only thing DriverQuirks does is handle type mapping. getCatalystType is used when reading from a JDBC table and getJDBCType is used when writing to a JDBC table. If getCatalystType returns null, the default type handling is used for the given JDBC type. Similarly, if getJDBCType returns (null, None), the default type handling is used for the given Catalyst type.

Constructor Summary

Constructors

Constructor and Description
DriverQuirks()

Method Summary

Methods

Modifier and Type	Method and Description
static DriverQuirks	get(String url) Fetch the DriverQuirks class corresponding to a given database url.
abstract org.apache.spark.sql.types.DataType	getCatalystType(int sqlType, String typeName, int size, org.apache.spark.sql.types.MetadataBuilder md)
abstract scala.Tuple2<String,scala.Option<Object>>	getJDBCType(org.apache.spark.sql.types.DataType dt)

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DriverQuirks

public DriverQuirks()

Method Detail

get

public static DriverQuirks get(String url)

Fetch the DriverQuirks class corresponding to a given database url.

getCatalystType

public abstract org.apache.spark.sql.types.DataType getCatalystType(int sqlType,
                                                  String typeName,
                                                  int size,
                                                  org.apache.spark.sql.types.MetadataBuilder md)

getJDBCType

public abstract scala.Tuple2<String,scala.Option<Object>> getJDBCType(org.apache.spark.sql.types.DataType dt)