2 * ============LICENSE_START=======================================================
3 * Copyright (C) 2022 Nordix Foundation.
4 * ================================================================================
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 * SPDX-License-Identifier: Apache-2.0
18 * ============LICENSE_END=========================================================
21 package org.onap.cps.spi.repository;
23 import java.util.Arrays;
24 import java.util.Collection;
25 import java.util.HashSet;
26 import java.util.Iterator;
27 import java.util.List;
28 import java.util.UUID;
29 import javax.persistence.EntityManager;
30 import javax.persistence.PersistenceContext;
31 import lombok.AllArgsConstructor;
32 import lombok.extern.slf4j.Slf4j;
33 import org.springframework.stereotype.Component;
34 import org.springframework.transaction.annotation.Transactional;
40 public class TempTableCreator {
43 private EntityManager entityManager;
46 * Create a uniquely named temporary table.
48 * @param prefix prefix for the table name (so you can recognize it)
49 * @param sqlData data to insert (strings only) the inner List present a row of data
50 * @param columnNames column names (in same order as data in rows in sqlData)
51 * @return a unique temporary table name with given prefix
53 public String createTemporaryTable(final String prefix,
54 final Collection<List<String>> sqlData,
55 final String... columnNames) {
56 final String tempTableName = prefix + UUID.randomUUID().toString().replace("-", "");
57 final StringBuilder sqlStringBuilder = new StringBuilder("CREATE TEMPORARY TABLE ");
58 sqlStringBuilder.append(tempTableName);
59 defineColumns(sqlStringBuilder, columnNames);
60 insertData(sqlStringBuilder, tempTableName, columnNames, sqlData);
61 entityManager.createNativeQuery(sqlStringBuilder.toString()).executeUpdate();
65 private static void defineColumns(final StringBuilder sqlStringBuilder, final String[] columnNames) {
66 sqlStringBuilder.append('(');
67 final Iterator<String> it = Arrays.stream(columnNames).iterator();
68 while (it.hasNext()) {
69 final String columnName = it.next();
70 sqlStringBuilder.append(" ");
71 sqlStringBuilder.append(columnName);
72 sqlStringBuilder.append(" varchar NOT NULL");
74 sqlStringBuilder.append(",");
77 sqlStringBuilder.append(");");
80 private static void insertData(final StringBuilder sqlStringBuilder,
81 final String tempTableName,
82 final String[] columnNames,
83 final Collection<List<String>> sqlData) {
84 final Collection<String> sqlInserts = new HashSet<>(sqlData.size());
85 for (final Collection<String> row : sqlData) {
86 sqlInserts.add("('" + String.join("','", row) + "')");
88 sqlStringBuilder.append("INSERT INTO ");
89 sqlStringBuilder.append(tempTableName);
90 sqlStringBuilder.append(" (");
91 sqlStringBuilder.append(String.join(",", columnNames));
92 sqlStringBuilder.append(") VALUES ");
93 sqlStringBuilder.append(String.join(",", sqlInserts));
94 sqlStringBuilder.append(";");