JdbcDialect

:: DeveloperApi :: Encapsulates everything (extensions, workarounds, quirks) to handle the SQL dialect of a certain database or jdbc driver. 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 done by the dialect is 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.

Annotations: @DeveloperApi() @Evolving()
Source: JdbcDialects.scala

Linear Supertypes

Serializable, Serializable, AnyRef, Any

Instance Constructors

new JdbcDialect()

Abstract Value Members

abstract def canHandle(url: String): Boolean

Check if this dialect instance can handle a certain jdbc url.
Check if this dialect instance can handle a certain jdbc url.
url
the jdbc url.
returns
True if the dialect can be applied on the given jdbc url.

Exceptions thrown
NullPointerException if the url is null.

Concrete Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def beforeFetch(connection: Connection, properties: Map[String, String]): Unit

Override connection specific properties to run before a select is made.
Override connection specific properties to run before a select is made. This is in place to allow dialects that need special treatment to optimize behavior.
connection
The connection object
properties
The connection properties. This is passed through from the relation.
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
def compileValue(value: Any): Any

Converts value to SQL expression.
Converts value to SQL expression.
value
The value to be converted.
returns
Converted value.

Annotations
@Since( "2.3.0" )
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def escapeSql(value: String): String

Escape special characters in SQL string literals.
Escape special characters in SQL string literals.
value
The string to be escaped.
returns
Escaped string.

Attributes
protected[org.apache.spark.sql.jdbc]
Annotations
@Since( "2.3.0" )
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
def getCatalystType(sqlType: Int, typeName: String, size: Int, md: MetadataBuilder): Option[DataType]

Get the custom datatype mapping for the given jdbc meta information.
Get the custom datatype mapping for the given jdbc meta information.
sqlType
The sql type (see java.sql.Types)
typeName
The sql type name (e.g. "BIGINT UNSIGNED")
size
The size of the type.
md
Result metadata associated with this type.
returns
The actual DataType (subclasses of org.apache.spark.sql.types.DataType) or null if the default type mapping should be used.
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def getJDBCType(dt: DataType): Option[JdbcType]

Retrieve the jdbc / sql type for a given datatype.
Retrieve the jdbc / sql type for a given datatype.
dt
The datatype (e.g. org.apache.spark.sql.types.StringType)
returns
The new JdbcType if there is an override for this DataType
def getSchemaQuery(table: String): String

The SQL query that should be used to discover the schema of a table.
The SQL query that should be used to discover the schema of a table. It only needs to ensure that the result set has the same schema as the table, such as by calling "SELECT * ...". Dialects can override this method to return a query that works best in a particular database.
table
The name of the table.
returns
The SQL query to use for discovering the schema.

Annotations
@Since( "2.1.0" )
def getTableExistsQuery(table: String): String

Get the SQL query that should be used to find if the given table exists.
Get the SQL query that should be used to find if the given table exists. Dialects can override this method to return a query that works best in a particular database.
table
The name of the table.
returns
The SQL query to use for checking the table.
def getTruncateQuery(table: String, cascade: Option[Boolean] = isCascadingTruncateTable): String

The SQL query that should be used to truncate a table.
The SQL query that should be used to truncate a table. Dialects can override this method to return a query that is suitable for a particular database. For PostgreSQL, for instance, a different query is used to prevent "TRUNCATE" affecting other tables.
table
The table to truncate
cascade
Whether or not to cascade the truncation
returns
The SQL query to use for truncating a table

Annotations
@Since( "2.4.0" )
def getTruncateQuery(table: String): String

The SQL query that should be used to truncate a table.
The SQL query that should be used to truncate a table. Dialects can override this method to return a query that is suitable for a particular database. For PostgreSQL, for instance, a different query is used to prevent "TRUNCATE" affecting other tables.
table
The table to truncate
returns
The SQL query to use for truncating a table

Annotations
@Since( "2.3.0" )
def hashCode(): Int

Definition Classes
AnyRef → Any
def isCascadingTruncateTable(): Option[Boolean]

Return Some[true] iff TRUNCATE TABLE causes cascading default.
Return Some[true] iff TRUNCATE TABLE causes cascading default. Some[true] : TRUNCATE TABLE causes cascading. Some[false] : TRUNCATE TABLE does not cause cascading. None: The behavior of TRUNCATE TABLE is unknown (default).
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def quoteIdentifier(colName: String): String

Quotes the identifier.
Quotes the identifier. This is used to put quotes around the identifier in case the column name is a reserved keyword, or in case it contains characters that require quotes (e.g. space).
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Doc: package jdbc

abstract class JdbcDialect extends Serializable

Instance Constructors

new JdbcDialect()

Abstract Value Members

abstract def canHandle(url: String): Boolean

Concrete Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def beforeFetch(connection: Connection, properties: Map[String, String]): Unit

def clone(): AnyRef

def compileValue(value: Any): Any

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def escapeSql(value: String): String

def finalize(): Unit

def getCatalystType(sqlType: Int, typeName: String, size: Int, md: MetadataBuilder): Option[DataType]

final def getClass(): Class[_]

def getJDBCType(dt: DataType): Option[JdbcType]

def getSchemaQuery(table: String): String

def getTableExistsQuery(table: String): String

def getTruncateQuery(table: String, cascade: Option[Boolean] = isCascadingTruncateTable): String

def getTruncateQuery(table: String): String

def hashCode(): Int

def isCascadingTruncateTable(): Option[Boolean]

final def isInstanceOf[T0]: Boolean

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def quoteIdentifier(colName: String): String

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped