org.jooq.impl.Greatest Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
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* http://www.apache.org/licenses/LICENSE-2.0
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* database integrations.
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* For more information, please visit: http://www.jooq.org/licenses
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package org.jooq.impl;
import static org.jooq.impl.DSL.function;
import org.jooq.Configuration;
import org.jooq.DataType;
import org.jooq.Field;
/**
* @author Lukas Eder
*/
final class Greatest extends AbstractFunction {
/**
* Generated UID
*/
private static final long serialVersionUID = -7273879239726265322L;
Greatest(DataType type, Field... arguments) {
super("greatest", type, arguments);
}
@SuppressWarnings("unchecked")
@Override
final Field getFunction0(Configuration configuration) {
// In any dialect, a single argument is always the greatest
if (getArguments().length == 1) {
return (Field) getArguments()[0];
}
switch (configuration.family()) {
// This implementation has O(2^n) complexity. Better implementations
// are very welcome
// [#1049] TODO Fix this!
case DERBY: {
Field first = (Field) getArguments()[0];
Field other = (Field) getArguments()[1];
if (getArguments().length > 2) {
Field[] remaining = new Field[getArguments().length - 2];
System.arraycopy(getArguments(), 2, remaining, 0, remaining.length);
return DSL
.when(first.greaterThan(other), DSL.greatest(first, remaining))
.otherwise(DSL.greatest(other, remaining));
}
else {
return DSL
.when(first.greaterThan(other), first)
.otherwise(other);
}
}
case FIREBIRD:
return function("maxvalue", getDataType(), getArguments());
case SQLITE:
return function("max", getDataType(), getArguments());
default:
return function("greatest", getDataType(), getArguments());
}
}
}