org.apache.flink.table.planner.functions.aggfunctions.MaxAggFunction Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.flink.table.planner.functions.aggfunctions;
import org.apache.flink.table.api.DataTypes;
import org.apache.flink.table.expressions.Expression;
import org.apache.flink.table.expressions.UnresolvedReferenceExpression;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.DecimalType;
import org.apache.flink.table.types.logical.LocalZonedTimestampType;
import org.apache.flink.table.types.logical.TimeType;
import org.apache.flink.table.types.logical.TimestampType;
import static org.apache.flink.table.expressions.ApiExpressionUtils.unresolvedRef;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.greaterThan;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.ifThenElse;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.isNull;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.nullOf;
/** built-in max aggregate function. */
public abstract class MaxAggFunction extends DeclarativeAggregateFunction {
private UnresolvedReferenceExpression max = unresolvedRef("max");
@Override
public int operandCount() {
return 1;
}
@Override
public UnresolvedReferenceExpression[] aggBufferAttributes() {
return new UnresolvedReferenceExpression[] {max};
}
@Override
public DataType[] getAggBufferTypes() {
return new DataType[] {getResultType()};
}
@Override
public Expression[] initialValuesExpressions() {
return new Expression[] {/* max = */ nullOf(getResultType())};
}
@Override
public Expression[] accumulateExpressions() {
return new Expression[] {
/* max = */ ifThenElse(
isNull(operand(0)),
max,
ifThenElse(
isNull(max),
operand(0),
ifThenElse(greaterThan(operand(0), max), operand(0), max)))
};
}
@Override
public Expression[] retractExpressions() {
// TODO FLINK-12295, ignore exception now
// throw new TableException("This function does not support retraction, Please choose
// MaxWithRetractAggFunction.");
return new Expression[0];
}
@Override
public Expression[] mergeExpressions() {
return new Expression[] {
/* max = */ ifThenElse(
isNull(mergeOperand(max)),
max,
ifThenElse(
isNull(max),
mergeOperand(max),
ifThenElse(
greaterThan(mergeOperand(max), max), mergeOperand(max), max)))
};
}
@Override
public Expression getValueExpression() {
return max;
}
/** Built-in Int Max aggregate function. */
public static class IntMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.INT();
}
}
/** Built-in Byte Max aggregate function. */
public static class ByteMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.TINYINT();
}
}
/** Built-in Short Max aggregate function. */
public static class ShortMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.SMALLINT();
}
}
/** Built-in Long Max aggregate function. */
public static class LongMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.BIGINT();
}
}
/** Built-in Float Max aggregate function. */
public static class FloatMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.FLOAT();
}
}
/** Built-in Double Max aggregate function. */
public static class DoubleMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.DOUBLE();
}
}
/** Built-in Decimal Max aggregate function. */
public static class DecimalMaxAggFunction extends MaxAggFunction {
private DecimalType decimalType;
public DecimalMaxAggFunction(DecimalType decimalType) {
this.decimalType = decimalType;
}
@Override
public DataType getResultType() {
return DataTypes.DECIMAL(decimalType.getPrecision(), decimalType.getScale());
}
}
/** Built-in Boolean Max aggregate function. */
public static class BooleanMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.BOOLEAN();
}
}
/** Built-in String Max aggregate function. */
public static class StringMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.STRING();
}
}
/** Built-in Date Max aggregate function. */
public static class DateMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.DATE();
}
}
/** Built-in Time Max aggregate function. */
public static class TimeMaxAggFunction extends MaxAggFunction {
@Override
public DataType getResultType() {
return DataTypes.TIME(TimeType.DEFAULT_PRECISION);
}
}
/** Built-in Timestamp Max aggregate function. */
public static class TimestampMaxAggFunction extends MaxAggFunction {
private final TimestampType type;
public TimestampMaxAggFunction(TimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP(type.getPrecision());
}
}
/** Built-in TimestampLtz Max aggregate function. */
public static class TimestampLtzMaxAggFunction extends MaxAggFunction {
private final LocalZonedTimestampType type;
public TimestampLtzMaxAggFunction(LocalZonedTimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP_LTZ(type.getPrecision());
}
}
}