org.jooq.impl.SelectIsNull 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.
* You may obtain a copy of the License at
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* https://www.apache.org/licenses/LICENSE-2.0
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* 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.
*
* Other licenses:
* -----------------------------------------------------------------------------
* Commercial licenses for this work are available. These replace the above
* Apache-2.0 license and offer limited warranties, support, maintenance, and
* commercial database integrations.
*
* For more information, please visit: https://www.jooq.org/legal/licensing
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package org.jooq.impl;
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import static org.jooq.SQLDialect.CUBRID;
// ...
import static org.jooq.SQLDialect.DERBY;
import static org.jooq.SQLDialect.DUCKDB;
// ...
import static org.jooq.SQLDialect.FIREBIRD;
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import static org.jooq.SQLDialect.HSQLDB;
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import static org.jooq.SQLDialect.MARIADB;
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import static org.jooq.SQLDialect.MYSQL;
// ...
import static org.jooq.SQLDialect.POSTGRES;
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import static org.jooq.SQLDialect.SQLITE;
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import static org.jooq.SQLDialect.TRINO;
// ...
import static org.jooq.SQLDialect.YUGABYTEDB;
import static org.jooq.impl.DSL.inline;
import static org.jooq.impl.DSL.selectCount;
import static org.jooq.impl.Keywords.K_IS_NULL;
import static org.jooq.impl.SubqueryCharacteristics.PREDICAND;
import static org.jooq.impl.Tools.allNull;
import static org.jooq.impl.Tools.collect;
import static org.jooq.impl.Tools.fieldNames;
import static org.jooq.impl.Tools.fieldsByName;
import static org.jooq.impl.Tools.flattenCollection;
import static org.jooq.impl.Tools.visitSubquery;
import java.util.List;
import java.util.Set;
import org.jooq.Clause;
import org.jooq.Context;
import org.jooq.Field;
import org.jooq.Function1;
import org.jooq.Name;
import org.jooq.SQLDialect;
import org.jooq.Select;
import org.jooq.Table;
/**
* @author Lukas Eder
*/
final class SelectIsNull extends AbstractCondition implements QOM.SelectIsNull {
static final Set EMULATE_NULL_QUERY = SQLDialect.supportedBy(CUBRID, DERBY, DUCKDB, FIREBIRD, HSQLDB, MARIADB, MYSQL, POSTGRES, SQLITE, TRINO, YUGABYTEDB);
final Select select;
SelectIsNull(Select select) {
this.select = select;
}
@Override
final boolean isNullable() {
return false;
}
@Override
public final void accept(Context ctx) {
if (EMULATE_NULL_QUERY.contains(ctx.dialect())) {
// [#11011] Avoid the RVE IS NULL emulation for queries of degree 1
// [#16319] Flatten embeddables to find collection size
List> f = collect(flattenCollection(select.getSelect()));
if (f.size() == 1) {
acceptStandard(ctx);
}
else {
Name[] n = fieldNames(f.size());
Table t = new AliasedSelect<>(select, true, true, false, n).as("t");
ctx.visit(inline(1).eq(selectCount().from(t).where(allNull(fieldsByName(n)))));
}
}
else
acceptStandard(ctx);
}
private final void acceptStandard(Context ctx) {
visitSubquery(ctx, select, PREDICAND);
switch (ctx.family()) {
default:
ctx.sql(' ')
.visit(K_IS_NULL);
break;
}
}
@Override // Avoid AbstractCondition implementation
public final Clause[] clauses(Context ctx) {
return null;
}
// -------------------------------------------------------------------------
// XXX: Query Object Model
// -------------------------------------------------------------------------
@Override
public final Select $arg1() {
return select;
}
@Override
public final Function1, ? extends QOM.SelectIsNull> $constructor() {
return r -> new SelectIsNull(r);
}
}