Package org.apache.calcite.sql.dialect

Class OracleSqlDialect

java.lang.Object

org.apache.calcite.sql.SqlDialect

org.apache.calcite.sql.dialect.OracleSqlDialect

public class OracleSqlDialect
extends SqlDialect

A SqlDialect implementation for the Oracle database.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.sql.SqlDialect

SqlDialect.CalendarPolicy, SqlDialect.Context, SqlDialect.DatabaseProduct, SqlDialect.FakeUtil

Field Summary

Fields

Modifier and Type	Field	Description
static final SqlDialect	DEFAULT
static final SqlDialect.Context	DEFAULT_CONTEXT

Fields inherited from class org.apache.calcite.sql.SqlDialect

BUILT_IN_OPERATORS_LIST, EMPTY_CONTEXT, identifierEndQuoteString, identifierEscapedQuote, identifierQuoteString, literalEndQuoteString, literalEscapedQuote, literalQuoteString, LOGGER, nullCollation

Constructor Summary

Constructors

Constructor	Description
OracleSqlDialect(SqlDialect.Context context)	Creates an OracleSqlDialect.

Method Summary

Modifier and Type	Method	Description
protected boolean	allowsAs()
@Nullable SqlNode	getCastSpec(RelDataType type)	Returns SqlNode for type in "cast(column as type)", which might be different between databases by type name, precision etc.
List<String>	getSingleRowTableName()	Returns the name of the system table that has precisely one row.
boolean	supportBooleanCaseWhen()	Returns whether this dialect supports case when return boolean type.
boolean	supportsAliasedValues()	Returns whether the dialect supports VALUES in a sub-query with and an "AS t(column, ...)" values to define column names.
boolean	supportsApproxCountDistinct()	Returns whether this dialect supports APPROX_COUNT_DISTINCT functions.
boolean	supportsCharSet()	Returns whether the dialect supports character set names as part of a data type, for instance VARCHAR(30) CHARACTER SET `ISO-8859-1`.
boolean	supportsDataType(RelDataType type)	Returns whether this dialect supports a given type.
void	unparseBoolLiteral(SqlWriter writer, SqlLiteral literal, int leftPrec, int rightPrec)
void	unparseCall(SqlWriter writer, SqlCall call, int leftPrec, int rightPrec)
void	unparseDateTimeLiteral(SqlWriter writer, SqlAbstractDateTimeLiteral literal, int leftPrec, int rightPrec)
void	unparseOffsetFetch(SqlWriter writer, @Nullable SqlNode offset, @Nullable SqlNode fetch)	Converts an offset and fetch into SQL.

Methods inherited from class org.apache.calcite.sql.SqlDialect

configureParser, configureParser, containsNonAscii, create, defaultNullDirection, emulateJoinTypeForCrossJoin, emulateNullDirection, emulateNullDirectionWithIsNull, getCalendarPolicy, getConformance, getDatabaseProduct, getFormatModel, getNullCollation, getProduct, getQuotedCasing, getQuoting, getTypeSystem, getUnquotedCasing, hasImplicitTableAlias, identifierNeedsQuote, isCaseSensitive, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteStringLiteral, quoteStringLiteral, quoteStringLiteralUnicode, quoteTimestampLiteral, requiresAliasForFromItems, rewriteMaxMin, rewriteMaxMinExpr, rewriteSingleValueExpr, supportsAggregateFunction, supportsAggregateFunctionFilter, supportsFunction, supportsGroupByLiteral, supportsGroupByWithCube, supportsGroupByWithRollup, supportsImplicitTypeCoercion, supportsJoinType, supportsNestedAggregations, supportsOffsetFetch, supportsTimestampPrecision, supportsWindowFunctions, unparseFetchUsingAnsi, unparseFetchUsingLimit, unparseLimit, unparseOffset, unparseSqlDatetimeArithmetic, unparseSqlIntervalLiteral, unparseSqlIntervalQualifier, unparseTableScanHints, unparseTopN, unquoteStringLiteral

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_CONTEXT

public static final SqlDialect.Context DEFAULT_CONTEXT

DEFAULT

public static final SqlDialect DEFAULT

Constructor Details

OracleSqlDialect

public OracleSqlDialect(SqlDialect.Context context)

Creates an OracleSqlDialect.

Method Details

supportsApproxCountDistinct

public boolean supportsApproxCountDistinct()

Description copied from class: SqlDialect

Returns whether this dialect supports APPROX_COUNT_DISTINCT functions.

Overrides:

supportsApproxCountDistinct in class SqlDialect

supportsCharSet

public boolean supportsCharSet()

Description copied from class: SqlDialect

Returns whether the dialect supports character set names as part of a data type, for instance VARCHAR(30) CHARACTER SET `ISO-8859-1`.

Overrides:

supportsCharSet in class SqlDialect

supportBooleanCaseWhen

public boolean supportBooleanCaseWhen()

Description copied from class: SqlDialect

Returns whether this dialect supports case when return boolean type.

Overrides:

supportBooleanCaseWhen in class SqlDialect

supportsDataType

public boolean supportsDataType(RelDataType type)

Description copied from class: SqlDialect

Returns whether this dialect supports a given type.

Overrides:

supportsDataType in class SqlDialect

getCastSpec

public @Nullable SqlNode getCastSpec(RelDataType type)

Description copied from class: SqlDialect

Returns SqlNode for type in "cast(column as type)", which might be different between databases by type name, precision etc.

If this method returns null, the cast will be omitted. In the default implementation, this is the case for the NULL type, and therefore CAST(NULL AS <nulltype>) is rendered as NULL.

Overrides:

getCastSpec in class SqlDialect

allowsAs

protected boolean allowsAs()

Overrides:

allowsAs in class SqlDialect

supportsAliasedValues

public boolean supportsAliasedValues()

Description copied from class: SqlDialect

Returns whether the dialect supports VALUES in a sub-query with and an "AS t(column, ...)" values to define column names.

Currently, only Oracle does not. For this, we generate "SELECT v0 AS c0, v1 AS c1 ... UNION ALL ...". We may need to refactor this method when we support VALUES for other dialects.

Overrides:

supportsAliasedValues in class SqlDialect

unparseBoolLiteral

public void unparseBoolLiteral(SqlWriter writer,
 SqlLiteral literal,
 int leftPrec,
 int rightPrec)

Overrides:

unparseBoolLiteral in class SqlDialect

unparseDateTimeLiteral

public void unparseDateTimeLiteral(SqlWriter writer,
 SqlAbstractDateTimeLiteral literal,
 int leftPrec,
 int rightPrec)

Overrides:

unparseDateTimeLiteral in class SqlDialect

getSingleRowTableName

public List<String> getSingleRowTableName()

Description copied from class: SqlDialect

Returns the name of the system table that has precisely one row. If there is no such table, returns null, and we will generate SELECT with no FROM clause.

For VALUES 1, Oracle returns ["DUAL"] and we generate "SELECT 1 FROM DUAL"; MySQL returns null and we generate "SELECT 1".

Overrides:

getSingleRowTableName in class SqlDialect

unparseCall

public void unparseCall(SqlWriter writer,
 SqlCall call,
 int leftPrec,
 int rightPrec)

Overrides:

unparseCall in class SqlDialect

unparseOffsetFetch

public void unparseOffsetFetch(SqlWriter writer,
 @Nullable SqlNode offset,
 @Nullable SqlNode fetch)

Description copied from class: SqlDialect

Converts an offset and fetch into SQL.

At least one of offset and fetch must be provided.

Common options:

• OFFSET offset ROWS FETCH NEXT fetch ROWS ONLY (ANSI standard SQL, Oracle, PostgreSQL, and the default)
• LIMIT fetch OFFSET offset (Apache Hive, MySQL, Redshift)

Overrides:

unparseOffsetFetch in class SqlDialect

Parameters:

writer - Writer

offset - Number of rows to skip before emitting, or null

fetch - Number of rows to fetch, or null

See Also:

• SqlDialect.unparseFetchUsingAnsi(SqlWriter, SqlNode, SqlNode)
• SqlDialect.unparseFetchUsingLimit(SqlWriter, SqlNode, SqlNode)