org.apache.flink.table.planner.functions.aggfunctions.MinAggFunction 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.ifThenElse;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.isNull;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.lessThan;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.nullOf;
/** built-in min aggregate function. */
public abstract class MinAggFunction extends DeclarativeAggregateFunction {
private UnresolvedReferenceExpression min = unresolvedRef("min");
@Override
public int operandCount() {
return 1;
}
@Override
public UnresolvedReferenceExpression[] aggBufferAttributes() {
return new UnresolvedReferenceExpression[] {min};
}
@Override
public DataType[] getAggBufferTypes() {
return new DataType[] {getResultType()};
}
@Override
public Expression[] initialValuesExpressions() {
return new Expression[] {/* min = */ nullOf(getResultType())};
}
@Override
public Expression[] accumulateExpressions() {
return new Expression[] {
/* min = */ ifThenElse(
isNull(operand(0)),
min,
ifThenElse(
isNull(min),
operand(0),
ifThenElse(lessThan(operand(0), min), operand(0), min)))
};
}
@Override
public Expression[] retractExpressions() {
// TODO FLINK-12295, ignore exception now
// throw new TableException("This function does not support retraction, Please choose
// MinWithRetractAggFunction.");
return new Expression[0];
}
@Override
public Expression[] mergeExpressions() {
return new Expression[] {
/* min = */ ifThenElse(
isNull(mergeOperand(min)),
min,
ifThenElse(
isNull(min),
mergeOperand(min),
ifThenElse(lessThan(mergeOperand(min), min), mergeOperand(min), min)))
};
}
@Override
public Expression getValueExpression() {
return min;
}
/** Built-in Int Min aggregate function. */
public static class IntMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.INT();
}
}
/** Built-in Byte Min aggregate function. */
public static class ByteMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.TINYINT();
}
}
/** Built-in Short Min aggregate function. */
public static class ShortMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.SMALLINT();
}
}
/** Built-in Long Min aggregate function. */
public static class LongMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.BIGINT();
}
}
/** Built-in Float Min aggregate function. */
public static class FloatMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.FLOAT();
}
}
/** Built-in Double Min aggregate function. */
public static class DoubleMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.DOUBLE();
}
}
/** Built-in Decimal Min aggregate function. */
public static class DecimalMinAggFunction extends MinAggFunction {
private DecimalType decimalType;
public DecimalMinAggFunction(DecimalType decimalType) {
this.decimalType = decimalType;
}
@Override
public DataType getResultType() {
return DataTypes.DECIMAL(decimalType.getPrecision(), decimalType.getScale());
}
}
/** Built-in Boolean Min aggregate function. */
public static class BooleanMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.BOOLEAN();
}
}
/** Built-in String Min aggregate function. */
public static class StringMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.STRING();
}
}
/** Built-in Date Min aggregate function. */
public static class DateMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.DATE();
}
}
/** Built-in Time Min aggregate function. */
public static class TimeMinAggFunction extends MinAggFunction {
@Override
public DataType getResultType() {
return DataTypes.TIME(TimeType.DEFAULT_PRECISION);
}
}
/** Built-in Timestamp Min aggregate function. */
public static class TimestampMinAggFunction extends MinAggFunction {
private final TimestampType type;
public TimestampMinAggFunction(TimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP(type.getPrecision());
}
}
/** Built-in TimestampLtz Min aggregate function. */
public static class TimestampLtzMinAggFunction extends MinAggFunction {
private final LocalZonedTimestampType type;
public TimestampLtzMinAggFunction(LocalZonedTimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP_LTZ(type.getPrecision());
}
}
}