com.jn.sqlhelper.dialect.internal.FirebirdDialect 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.sqlhelper.dialect.pagination.RowSelection;
import com.jn.sqlhelper.dialect.internal.limit.AbstractLimitHandler;
import com.jn.sqlhelper.dialect.internal.limit.LimitHelper;
/**
* http://www.firebirdsql.org/file/documentation/reference_manuals/fblangref25-en/html/fblangref25-dml-select.html#fblangref25-dml-select-first-skip
* http://www.firebirdsql.org/file/documentation/reference_manuals/fblangref25-en/html/fblangref25-commons-predicates.html
*/
public class FirebirdDialect extends InterbaseDialect {
public FirebirdDialect() {
super();
setLimitHandler(new AbstractLimitHandler() {
@Override
public String processSql(String sql, boolean isSubQuery, boolean useLimitVariable, RowSelection selection) {
boolean hasOffset = LimitHelper.hasFirstRow(selection);
sql = sql.trim();
StringBuilder sqlbuiler = new StringBuilder(sql.length() + 20).append(sql);
String substring = "";
if(useLimitVariable && isUseLimitInVariableMode(isSubQuery)){
substring = hasOffset ? " first ? skip ?" : " first ?";
}else{
int firstRow = (int)convertToFirstRowValue(LimitHelper.getFirstRow(selection));
int lastRow = getMaxOrLimit(selection);
substring = " first "+lastRow ;
if(hasOffset){
substring = " skip "+ firstRow +" ";
}
}
return sqlbuiler.insert(6, substring).toString();
}
});
}
@Override
public boolean isSupportsLimit() {
return true;
}
@Override
public boolean isBindLimitParametersFirst() {
return true;
}
@Override
public boolean isBindLimitParametersInReverseOrder() {
return true;
}
}