com.blazebit.persistence.impl.function.tostringjson.MySQLToStringJsonFunction Maven / Gradle / Ivy
/*
* Copyright 2014 - 2020 Blazebit.
*
* 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.
*/
package com.blazebit.persistence.impl.function.tostringjson;
import com.blazebit.persistence.impl.util.SqlUtils;
import com.blazebit.persistence.spi.FunctionRenderContext;
/**
* @author Christian Beikov
* @since 1.5.0
*/
public class MySQLToStringJsonFunction extends AbstractToStringJsonFunction {
private static final String START_CHUNK = "(select json_arrayagg(json_object('";
@Override
public void render(FunctionRenderContext context, String[] fields, String[] selectItemExpressions, String subquery, int fromIndex) {
context.addChunk(START_CHUNK);
int orderByIndex = SqlUtils.indexOfOrderBy(subquery, fromIndex);
if (orderByIndex == -1) {
renderJsonObjectArguments(context, fields, selectItemExpressions);
context.addChunk("))");
context.addChunk(subquery.substring(fromIndex));
} else {
int limitIndex = SqlUtils.indexOfLimit(subquery, orderByIndex);
if (limitIndex == -1) {
renderJsonObjectArguments(context, fields, selectItemExpressions);
context.addChunk("))");
context.addChunk(" OVER (");
context.addChunk(subquery.substring(orderByIndex));
context.addChunk(")");
context.addChunk(subquery.substring(fromIndex, orderByIndex));
} else {
renderJsonObjectArguments(context, fields, fields);
context.addChunk("))");
context.addChunk(" from (select ");
for (int i = 0; i < fields.length; i++) {
if (i != 0) {
context.addChunk(",");
}
context.addChunk(selectItemExpressions[i]);
context.addChunk(" ");
context.addChunk(fields[i]);
}
context.addChunk(subquery.substring(fromIndex));
context.addChunk(" tmp)");
}
}
}
private void renderJsonObjectArguments(FunctionRenderContext context, String[] fields, String[] selectItemExpressions) {
for (int i = 0; i < fields.length; i++) {
if (i != 0) {
context.addChunk(",'");
}
context.addChunk(fields[i]);
context.addChunk("',");
if (selectItemExpressions[i].startsWith(START_CHUNK)) {
context.addChunk(selectItemExpressions[i]);
} else {
context.addChunk("cast(");
context.addChunk(selectItemExpressions[i]);
context.addChunk(" as char)");
}
}
}
}