org.jooq.impl.Limit Maven / Gradle / Ivy
/**
* Copyright (c) 2009-2014, Data Geekery GmbH (http://www.datageekery.com)
* All rights reserved.
*
* This work is dual-licensed
* - under the Apache Software License 2.0 (the "ASL")
* - under the jOOQ License and Maintenance Agreement (the "jOOQ License")
* =============================================================================
* You may choose which license applies to you:
*
* - If you're using this work with Open Source databases, you may choose
* either ASL or jOOQ License.
* - If you're using this work with at least one commercial database, you must
* choose jOOQ License
*
* For more information, please visit http://www.jooq.org/licenses
*
* Apache Software License 2.0:
* -----------------------------------------------------------------------------
* 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
*
* 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.
*
* jOOQ License and Maintenance Agreement:
* -----------------------------------------------------------------------------
* Data Geekery grants the Customer the non-exclusive, timely limited and
* non-transferable license to install and use the Software under the terms of
* the jOOQ License and Maintenance Agreement.
*
* This library is distributed with a LIMITED WARRANTY. See the jOOQ License
* and Maintenance Agreement for more details: http://www.jooq.org/licensing
*/
package org.jooq.impl;
import static org.jooq.RenderContext.CastMode.NEVER;
import static org.jooq.conf.ParamType.INLINED;
import static org.jooq.impl.DSL.inline;
import static org.jooq.impl.DSL.val;
import org.jooq.Clause;
import org.jooq.Context;
import org.jooq.Field;
import org.jooq.Param;
import org.jooq.RenderContext.CastMode;
import org.jooq.conf.ParamType;
import org.jooq.exception.DataAccessException;
/**
* @author Lukas Eder
*/
class Limit extends AbstractQueryPart {
/**
* Generated UID
*/
private static final long serialVersionUID = 2053741242981425602L;
private Field numberOfRows;
private Field offset;
private Field offsetOrZero = inline(0);
private Field offsetPlusOne = inline(1);
private boolean rendersParams;
@Override
public final void accept(Context context) {
ParamType paramType = context.paramType();
CastMode castMode = context.castMode();
switch (context.configuration().dialect()) {
// True LIMIT / OFFSET support provided by the following dialects
// -----------------------------------------------------------------
case MARIADB:
case MYSQL: // No break
case H2: // No break
case HSQLDB: // No break
case POSTGRES: // No break
case SQLITE: {
context.castMode(NEVER)
.formatSeparator()
.keyword("limit")
.sql(" ").visit(numberOfRows);
if (!offsetZero())
context.sql(" ").keyword("offset")
.sql(" ").visit(offsetOrZero);
context.castMode(castMode);
break;
}
// LIMIT [offset], [limit] supported by CUBRID
// -------------------------------------------
case CUBRID: {
context.castMode(NEVER)
.formatSeparator()
.keyword("limit")
.sql(" ").visit(offsetOrZero)
.sql(", ").visit(numberOfRows)
.castMode(castMode);
break;
}
// ROWS .. TO ..
// -------------
case FIREBIRD: {
context.castMode(NEVER)
.formatSeparator()
.keyword("rows")
.sql(" ").visit(getLowerRownum().add(inline(1)))
.sql(" ").keyword("to")
.sql(" ").visit(getUpperRownum())
.castMode(castMode);
break;
}
/* [pro] xx
xxxx xxxxxxxxxx
xxxx xxxxxxxxxxxxxx
xx [/pro] */
case DERBY: {
// Casts are not supported here...
context.castMode(NEVER)
.formatSeparator()
.keyword("offset")
.sql(" ").visit(offsetOrZero)
.sql(" ").keyword("rows fetch next")
.sql(" ").visit(numberOfRows)
.sql(" ").keyword("rows only")
.castMode(castMode);
break;
}
/* [pro] xx
xxxx xxxxxxx x
xx xxxxxx xxxxxxx xxxxx xxxx xxxxxxxxx xx xxx
xx xxxxxx x xxxxx xxxxx x xxxx xxxx xxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxx
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xx xxxx xxxx xx xxxxx xxxxxxx
xx xxxxxxxxxxxxxxxxxxxxxxxxxxxx
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xx xxxxxxxxxxxxxxx
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xxxxxx xxxxxxxxxxxxxxxxxxxxxx
xxxxxx xxx
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x
xx xxxx xxx xx xxxxx xx xxxxxxx
xx xxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxx xxxxxxx x
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xx xxxxxxxxxxxxxxx
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xxxxxx xxxxxxxxxxxxxxxxxxxxxxxx
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xx xxxx xxxxx xxxxxxx xxxxxxxx xx xxx xxxxxxxxx xxxxxxxxx
xx xxxxxxxx xxxxxxx xx xxxxxxxxx xxxx xxxxxx xxxxxxx
xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxx xxxx
xxxx xxxxxx
xxxx xxxxxxx x
xx xxxxxxx xx xxxxx x
xxxxx xxx xxxxxxxxxxxxxxxxxxxxxxxx xxxx xxx xxxxxxx xxxxxxx xx xxxxx xxxxx xxxx xxxx xxxxxxxxx
x
xx xxx xxxxxxx xxxxx xxxx xxxxxxxxx xxxxx xxxxxxx xx xxx xxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxx
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xxxxxxxxxxxxxxx xxxxxxx
xxxxxx xxxxxxxxxxxxxxxxxxxxxx
xxxxxx xxxxxxxxxxxxxxxx xxxxxx
xxxxxxxxxxxxxxxxxxxxxx
xxxxxx
x
xxxx xxxxxxx
xxxx xxxxxxxxxxx
xxxx xxxx
xxxx xxxxxxxxxxxxxx x
xx xxxxxxx xx xxxxx x
xxxxx xxx xxxxxxxxxxxxxxxxxxxxxxxxxxxx xx xxx xxxxxx xxx xxxxxxxxxxxx
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xx xxx xxxxxx xxx xxxxxx xxxxx xxxxx xxxx xxxxxxxxx xx xxx xxx x xxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxx
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xxxxxx xxxxxxxxxxxxxxxxxxxxxx
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xxxxxx
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xx [/pro] */
// A default implementation is necessary for hashCode() and toString()
default: {
context.castMode(NEVER)
.formatSeparator()
.keyword("limit")
.sql(" ").visit(numberOfRows);
if (!offsetZero())
context.sql(" ").keyword("offset")
.sql(" ").visit(offsetOrZero);
context.castMode(castMode);
break;
}
}
}
@Override
public final Clause[] clauses(Context ctx) {
return null;
}
/**
* Whether this limit has an offset of zero
*/
final boolean offsetZero() {
return offset == null;
}
/**
* The lower bound, such that ROW_NUMBER() > getLowerRownum()
*/
final Field getLowerRownum() {
return offsetOrZero;
}
/**
* The upper bound, such that ROW_NUMBER() <= getUpperRownum()
*/
final Field getUpperRownum() {
return offsetOrZero.add(numberOfRows);
}
/**
* Whether this LIMIT clause is applicable. If false, then no
* LIMIT clause should be rendered.
*/
final boolean isApplicable() {
return offset != null || numberOfRows != null;
}
/**
* Whether this LIMIT clause renders {@link Param} objects. This indicates
* to the SELECT statement, that it may need to prefer
* ROW_NUMBER() filtering over a TOP clause to
* allow for named parameters in the query, as the TOP clause
* may not accept bind variables.
*/
final boolean rendersParams() {
return rendersParams;
}
final void setOffset(int offset) {
if (offset != 0) {
this.offset = val(offset);
this.offsetOrZero = this.offset;
this.offsetPlusOne = val(offset + 1);
}
}
final void setOffset(Param offset) {
this.offset = offset;
this.offsetOrZero = offset;
this.rendersParams = true;
}
final void setNumberOfRows(int numberOfRows) {
this.numberOfRows = val(numberOfRows);
}
final void setNumberOfRows(Param numberOfRows) {
this.numberOfRows = numberOfRows;
this.rendersParams = true;
}
}