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/*
* 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.sql.{Date, Timestamp, Types}
import java.util.{Locale, TimeZone}
import scala.util.control.NonFatal
import org.apache.spark.sql.catalyst.util.DateTimeUtils
import org.apache.spark.sql.connector.expressions.Expression
import org.apache.spark.sql.execution.datasources.jdbc.JDBCOptions
import org.apache.spark.sql.internal.SQLConf
import org.apache.spark.sql.types._
private case object OracleDialect extends JdbcDialect {
private[jdbc] val BINARY_FLOAT = 100
private[jdbc] val BINARY_DOUBLE = 101
private[jdbc] val TIMESTAMPTZ = -101
override def canHandle(url: String): Boolean =
url.toLowerCase(Locale.ROOT).startsWith("jdbc:oracle")
private val distinctUnsupportedAggregateFunctions =
Set("VAR_POP", "VAR_SAMP", "STDDEV_POP", "STDDEV_SAMP", "COVAR_POP", "COVAR_SAMP", "CORR",
"REGR_INTERCEPT", "REGR_R2", "REGR_SLOPE", "REGR_SXY")
// scalastyle:off line.size.limit
// https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/Aggregate-Functions.html#GUID-62BE676B-AF18-4E63-BD14-25206FEA0848
// scalastyle:on line.size.limit
private val supportedAggregateFunctions =
Set("MAX", "MIN", "SUM", "COUNT", "AVG") ++ distinctUnsupportedAggregateFunctions
private val supportedFunctions = supportedAggregateFunctions
override def isSupportedFunction(funcName: String): Boolean =
supportedFunctions.contains(funcName)
class OracleSQLBuilder extends JDBCSQLBuilder {
override def visitAggregateFunction(
funcName: String, isDistinct: Boolean, inputs: Array[String]): String =
if (isDistinct && distinctUnsupportedAggregateFunctions.contains(funcName)) {
throw new UnsupportedOperationException(s"${this.getClass.getSimpleName} does not " +
s"support aggregate function: $funcName with DISTINCT");
} else {
super.visitAggregateFunction(funcName, isDistinct, inputs)
}
}
override def compileExpression(expr: Expression): Option[String] = {
val oracleSQLBuilder = new OracleSQLBuilder()
try {
Some(oracleSQLBuilder.build(expr))
} catch {
case NonFatal(e) =>
logWarning("Error occurs while compiling V2 expression", e)
None
}
}
private def supportTimeZoneTypes: Boolean = {
val timeZone = DateTimeUtils.getTimeZone(SQLConf.get.sessionLocalTimeZone)
// TODO: support timezone types when users are not using the JVM timezone, which
// is the default value of SESSION_LOCAL_TIMEZONE
timeZone == TimeZone.getDefault
}
override def getCatalystType(
sqlType: Int, typeName: String, size: Int, md: MetadataBuilder): Option[DataType] = {
sqlType match {
case Types.NUMERIC =>
val scale = if (null != md) md.build().getLong("scale") else 0L
size match {
// Handle NUMBER fields that have no precision/scale in special way
// because JDBC ResultSetMetaData converts this to 0 precision and -127 scale
// For more details, please see
// https://github.com/apache/spark/pull/8780#issuecomment-145598968
// and
// https://github.com/apache/spark/pull/8780#issuecomment-144541760
case 0 => Option(DecimalType(DecimalType.MAX_PRECISION, 10))
// Handle FLOAT fields in a special way because JDBC ResultSetMetaData converts
// this to NUMERIC with -127 scale
// Not sure if there is a more robust way to identify the field as a float (or other
// numeric types that do not specify a scale.
case _ if scale == -127L => Option(DecimalType(DecimalType.MAX_PRECISION, 10))
case _ => None
}
case TIMESTAMPTZ if supportTimeZoneTypes
=> Some(TimestampType) // Value for Timestamp with Time Zone in Oracle
case BINARY_FLOAT => Some(FloatType) // Value for OracleTypes.BINARY_FLOAT
case BINARY_DOUBLE => Some(DoubleType) // Value for OracleTypes.BINARY_DOUBLE
case _ => None
}
}
override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
// For more details, please see
// https://docs.oracle.com/cd/E19501-01/819-3659/gcmaz/
case BooleanType => Some(JdbcType("NUMBER(1)", java.sql.Types.BOOLEAN))
case IntegerType => Some(JdbcType("NUMBER(10)", java.sql.Types.INTEGER))
case LongType => Some(JdbcType("NUMBER(19)", java.sql.Types.BIGINT))
case FloatType => Some(JdbcType("NUMBER(19, 4)", java.sql.Types.FLOAT))
case DoubleType => Some(JdbcType("NUMBER(19, 4)", java.sql.Types.DOUBLE))
case ByteType => Some(JdbcType("NUMBER(3)", java.sql.Types.SMALLINT))
case ShortType => Some(JdbcType("NUMBER(5)", java.sql.Types.SMALLINT))
case StringType => Some(JdbcType("CLOB", java.sql.Types.CLOB))
case _ => None
}
override def compileValue(value: Any): Any = value match {
// The JDBC drivers support date literals in SQL statements written in the
// format: {d 'yyyy-mm-dd'} and timestamp literals in SQL statements written
// in the format: {ts 'yyyy-mm-dd hh:mm:ss.f...'}. For details, see
// 'Oracle Database JDBC Developer’s Guide and Reference, 11g Release 1 (11.1)'
// Appendix A Reference Information.
case stringValue: String => s"'${escapeSql(stringValue)}'"
case timestampValue: Timestamp => "{ts '" + timestampValue + "'}"
case dateValue: Date => "{d '" + dateValue + "'}"
case arrayValue: Array[Any] => arrayValue.map(compileValue).mkString(", ")
case _ => value
}
override def isCascadingTruncateTable(): Option[Boolean] = Some(false)
/**
* The SQL query used to truncate a table.
* @param table The table to truncate
* @param cascade Whether or not to cascade the truncation. Default value is the
* value of isCascadingTruncateTable()
* @return The SQL query to use for truncating a table
*/
override def getTruncateQuery(
table: String,
cascade: Option[Boolean] = isCascadingTruncateTable): String = {
cascade match {
case Some(true) => s"TRUNCATE TABLE $table CASCADE"
case _ => s"TRUNCATE TABLE $table"
}
}
// see https://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_3001.htm#SQLRF01001
override def getAddColumnQuery(
tableName: String,
columnName: String,
dataType: String): String =
s"ALTER TABLE $tableName ADD ${quoteIdentifier(columnName)} $dataType"
// see https://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_3001.htm#SQLRF01001
override def getUpdateColumnTypeQuery(
tableName: String,
columnName: String,
newDataType: String): String =
s"ALTER TABLE $tableName MODIFY ${quoteIdentifier(columnName)} $newDataType"
override def getUpdateColumnNullabilityQuery(
tableName: String,
columnName: String,
isNullable: Boolean): String = {
val nullable = if (isNullable) "NULL" else "NOT NULL"
s"ALTER TABLE $tableName MODIFY ${quoteIdentifier(columnName)} $nullable"
}
override def getLimitClause(limit: Integer): String = {
// Oracle doesn't support LIMIT clause.
// We can use rownum <= n to limit the number of rows in the result set.
if (limit > 0) s"WHERE rownum <= $limit" else ""
}
override def getOffsetClause(offset: Integer): String = {
// Oracle doesn't support OFFSET clause.
// We can use rownum > n to skip some rows in the result set.
// Note: rn is an alias of rownum.
if (offset > 0) s"WHERE rn > $offset" else ""
}
class OracleSQLQueryBuilder(dialect: JdbcDialect, options: JDBCOptions)
extends JdbcSQLQueryBuilder(dialect, options) {
override def build(): String = {
val selectStmt = s"SELECT $columnList FROM ${options.tableOrQuery} $tableSampleClause" +
s" $whereClause $groupByClause $orderByClause"
val finalSelectStmt = if (limit > 0) {
if (offset > 0) {
// Because the rownum is calculated when the value is returned,
// if we not give an alias for rownum and using it directly, e.g.
// SELECT $columnList FROM ($selectStmt) tab WHERE rownum > $offset AND
// rownum <= ${limit + offset}. The result is incorrect.
s"SELECT $columnList FROM (SELECT tab.*, rownum rn FROM ($selectStmt) tab)" +
s" WHERE rn > $offset AND rn <= ${limit + offset}"
} else {
val limitClause = dialect.getLimitClause(limit)
s"SELECT tab.* FROM ($selectStmt) tab $limitClause"
}
} else if (offset > 0) {
val offsetClause = dialect.getOffsetClause(offset)
// Using rownum directly will lead to incorrect result too.
s"SELECT $columnList FROM (SELECT tab.*, rownum rn FROM ($selectStmt) tab) $offsetClause"
} else {
selectStmt
}
options.prepareQuery + finalSelectStmt
}
}
override def getJdbcSQLQueryBuilder(options: JDBCOptions): JdbcSQLQueryBuilder =
new OracleSQLQueryBuilder(this, options)
override def supportsLimit: Boolean = true
override def supportsOffset: Boolean = true
}
