com.jn.sqlhelper.dialect.internal.MonetDialect Maven / Gradle / Ivy
/*
* Copyright 2019 the original author or authors.
*
* Licensed under the LGPL, Version 3.0 (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.gnu.org/licenses/lgpl-3.0.html
*
* 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.
*/
package com.jn.sqlhelper.dialect.internal;
import com.jn.langx.util.regexp.Regexp;
import com.jn.langx.util.regexp.Regexps;
import com.jn.sqlhelper.dialect.internal.limit.LimitHelper;
import com.jn.sqlhelper.dialect.pagination.RowSelection;
import com.jn.sqlhelper.dialect.internal.limit.AbstractLimitHandler;
public class MonetDialect extends AbstractDialect {
private static final Regexp SAMPLE_SQL_PATTERN = Regexps.createRegexp(".* sample\\w+(\\d+|\\?)$");
public MonetDialect() {
super();
setLimitHandler(new AbstractLimitHandler() {
/**
* https://www.monetdb.org/Documentation/Manuals/SQLreference/SQLSyntaxOverview#SELECT
*/
@Override
public String processSql(String sql, boolean isSubquery, boolean useLimitVariable, RowSelection selection) {
sql = sql.trim();
while (sql.endsWith(";")) {
sql = sql.substring(0, sql.length() - 1);
}
String lowercaseSql = sql.toLowerCase();
boolean hasSampleClause = false;
String sampleSql = null;
if (SAMPLE_SQL_PATTERN.matcher(lowercaseSql).matches()) {
hasSampleClause = true;
int lastIndex = lowercaseSql.lastIndexOf("sample");
sampleSql = " " + sql.substring(lastIndex);
sql = sql.substring(0, lastIndex);
}
boolean hasOffset = selection.hasOffset();
if(useLimitVariable && isUseLimitInVariableMode(isSubquery)) {
sql = sql + (hasOffset ? " limit ? offset ? " : " limit ? ") ;
}else{
int lastRow = getMaxOrLimit(selection);
sql = sql + " limit " + lastRow;
if(hasOffset){
int firstRow = (int)convertToFirstRowValue(LimitHelper.getFirstRow(selection));
sql = sql + " offset "+ firstRow;
}
}
sql = sql + (hasSampleClause ? sampleSql : "");
return sql;
}
});
}
@Override
public boolean isSupportsLimitOffset() {
return true;
}
@Override
public boolean isSupportsLimit() {
return true;
}
@Override
public boolean isBindLimitParametersInReverseOrder() {
return true;
}
}