Package org.apache.spark.sql.jdbc

Class DerbyDialect

Object

org.apache.spark.sql.jdbc.JdbcDialect

org.apache.spark.sql.jdbc.DerbyDialect

All Implemented Interfaces:

Serializable, org.apache.spark.internal.Logging, NoLegacyJDBCError, scala.Equals, scala.Product

public class DerbyDialect
extends JdbcDialect
implements NoLegacyJDBCError, scala.Product, Serializable

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.spark.internal.Logging

org.apache.spark.internal.Logging.LogStringContext, org.apache.spark.internal.Logging.SparkShellLoggingFilter

Constructor Summary

Constructors

Constructor	Description
DerbyDialect()

Method Summary

Modifier and Type	Method	Description
abstract static R	apply()
boolean	canHandle(String url)	Check if this dialect instance can handle a certain jdbc url.
scala.Option<DataType>	getCatalystType(int sqlType, String typeName, int size, MetadataBuilder md)	Get the custom datatype mapping for the given jdbc meta information.
scala.Option<JdbcType>	getJDBCType(DataType dt)	Retrieve the jdbc / sql type for a given datatype.
String	getLimitClause(Integer limit)	Returns the LIMIT clause for the SELECT statement
String	getTableCommentQuery(String table, String comment)
String	getUpdateColumnNullabilityQuery(String tableName, String columnName, boolean isNullable)
scala.Option<Object>	isCascadingTruncateTable()	Return Some[true] iff TRUNCATE TABLE causes cascading default.
boolean	isSupportedFunction(String funcName)	Returns whether the database supports function.
String	renameTable(Identifier oldTable, Identifier newTable)	Rename an existing table.
static String	toString()

Methods inherited from class org.apache.spark.sql.jdbc.JdbcDialect

alterTable, beforeFetch, classifyException, classifyException, compileAggregate, compileExpression, compileValue, convertJavaDateToDate, convertJavaTimestampToTimestamp, convertJavaTimestampToTimestampNTZ, convertTimestampNTZToJavaTimestamp, createConnectionFactory, createIndex, createSchema, createTable, dropIndex, dropSchema, dropTable, functions, getAddColumnQuery, getDayTimeIntervalAsMicros, getDeleteColumnQuery, getFullyQualifiedQuotedTableName, getJdbcSQLQueryBuilder, getOffsetClause, getRenameColumnQuery, getSchemaCommentQuery, getSchemaQuery, getTableExistsQuery, getTableSample, getTruncateQuery, getTruncateQuery, getUpdateColumnTypeQuery, getYearMonthIntervalAsMonths, indexExists, insertIntoTable, listIndexes, listSchemas, quoteIdentifier, removeSchemaCommentQuery, renameTable, schemasExists, supportsLimit, supportsOffset, supportsTableSample, updateExtraColumnMeta

Methods inherited from class java.lang.Object

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

Methods inherited from interface scala.Equals

canEqual, equals

Methods inherited from interface org.apache.spark.internal.Logging

initializeForcefully, initializeLogIfNecessary, initializeLogIfNecessary, initializeLogIfNecessary$default$2, isTraceEnabled, log, logDebug, logDebug, logDebug, logDebug, logError, logError, logError, logError, logInfo, logInfo, logInfo, logInfo, logName, LogStringContext, logTrace, logTrace, logTrace, logTrace, logWarning, logWarning, logWarning, logWarning, org$apache$spark$internal$Logging$$log_, org$apache$spark$internal$Logging$$log__$eq, withLogContext

Methods inherited from interface org.apache.spark.sql.jdbc.NoLegacyJDBCError

classifyException

Methods inherited from interface scala.Product

productArity, productElement, productElementName, productElementNames, productIterator, productPrefix

Constructor Details

DerbyDialect

public DerbyDialect()

Method Details

apply

public abstract static R apply()

toString

public static String toString()

canHandle

public boolean canHandle(String url)

Description copied from class: JdbcDialect

Check if this dialect instance can handle a certain jdbc url.

Specified by:

canHandle in class JdbcDialect

Parameters:

url - the jdbc url.

Returns:

True if the dialect can be applied on the given jdbc url.

isSupportedFunction

public boolean isSupportedFunction(String funcName)

Description copied from class: JdbcDialect

Returns whether the database supports function.

Overrides:

isSupportedFunction in class JdbcDialect

Parameters:

funcName - Upper-cased function name

Returns:

True if the database supports function.

getCatalystType

public scala.Option<DataType> getCatalystType(int sqlType,
 String typeName,
 int size,
 MetadataBuilder md)

Description copied from class: JdbcDialect

Get the custom datatype mapping for the given jdbc meta information.

Guidelines for mapping database defined timestamps to Spark SQL timestamps:

• TIMESTAMP WITHOUT TIME ZONE if preferTimestampNTZ -> TimestampNTZType
• TIMESTAMP WITHOUT TIME ZONE if !preferTimestampNTZ -> TimestampType(LTZ)
• TIMESTAMP WITH TIME ZONE -> TimestampType(LTZ)
• TIMESTAMP WITH LOCAL TIME ZONE -> TimestampType(LTZ)
• If the TIMESTAMP cannot be distinguished by sqlType and typeName, preferTimestampNTZ is respected for now, but we may need to add another option in the future if necessary.

Overrides:

getCatalystType in class JdbcDialect

Parameters:

sqlType - Refers to Types constants, or other constants defined by the target database, e.g. -101 is Oracle's TIMESTAMP WITH TIME ZONE type. This value is returned by ResultSetMetaData.getColumnType(int).

typeName - The column type name used by the database (e.g. "BIGINT UNSIGNED"). This is sometimes used to determine the target data type when sqlType is not sufficient if multiple database types are conflated into a single id. This value is returned by ResultSetMetaData.getColumnTypeName(int).

size - The size of the type, e.g. the maximum precision for numeric types, length for character string, etc. This value is returned by ResultSetMetaData.getPrecision(int).

md - Result metadata associated with this type. This contains additional information from ResultSetMetaData or user specified options.

• isTimestampNTZ: Whether read a TIMESTAMP WITHOUT TIME ZONE value as TimestampNTZType or not. This is configured by JDBCOptions.preferTimestampNTZ.
• scale: The length of fractional part ResultSetMetaData.getScale(int)

Returns:

An option the actual DataType (subclasses of DataType) or None if the default type mapping should be used.

getJDBCType

public scala.Option<JdbcType> getJDBCType(DataType dt)

Description copied from class: JdbcDialect

Retrieve the jdbc / sql type for a given datatype.

Overrides:

getJDBCType in class JdbcDialect

Parameters:

dt - The datatype (e.g. StringType)

Returns:

The new JdbcType if there is an override for this DataType

isCascadingTruncateTable

public scala.Option<Object> isCascadingTruncateTable()

Description copied from class: JdbcDialect

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).

Overrides:

isCascadingTruncateTable in class JdbcDialect

Returns:

(undocumented)

renameTable

public String renameTable(Identifier oldTable,
 Identifier newTable)

Description copied from class: JdbcDialect

Rename an existing table.

Overrides:

renameTable in class JdbcDialect

Parameters:

oldTable - The existing table.

newTable - New name of the table.

Returns:

The SQL statement to use for renaming the table.

getTableCommentQuery

public String getTableCommentQuery(String table,
 String comment)

Overrides:

getTableCommentQuery in class JdbcDialect

getUpdateColumnNullabilityQuery

public String getUpdateColumnNullabilityQuery(String tableName,
 String columnName,
 boolean isNullable)

Overrides:

getUpdateColumnNullabilityQuery in class JdbcDialect

getLimitClause

public String getLimitClause(Integer limit)

Description copied from class: JdbcDialect

Returns the LIMIT clause for the SELECT statement

Overrides:

getLimitClause in class JdbcDialect

Parameters:

limit - (undocumented)

Returns:

(undocumented)