org.kaaproject.kaa.server.datamigration.utils.datadefinition.DataDefinition.java Source code

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Here is the source code for org.kaaproject.kaa.server.datamigration.utils.datadefinition.DataDefinition.java

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/*
 * Copyright 2014-2016 CyberVision, Inc.
 *
 * 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 org.kaaproject.kaa.server.datamigration.utils.datadefinition;

import static java.lang.String.format;

import org.apache.commons.dbutils.QueryRunner;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class DataDefinition {
    private static final String QUERY_FIND_FK_NAME = "SELECT CONSTRAINT_NAME FROM "
            + "INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_SCHEMA = 'kaa'"
            + " AND TABLE_NAME = '%s' and referenced_table_name='%s'";

    private Connection connection;

    public DataDefinition(Connection connection) {
        this.connection = connection;
    }

    public AlterBuilder alterTable(String tableName) {
        return new AlterBuilder(tableName);
    }

    /**
     * Drop foreign key with autogenerated name based on the table where constrain declared and
     * referenced table name.
     */
    public void dropUnnamedFk(String tableName, String referencedTableName) throws SQLException {
        QueryRunner runner = new QueryRunner();
        String query = String.format(QUERY_FIND_FK_NAME, tableName, referencedTableName);
        String fkName = runner.query(connection, query, rs -> rs.next() ? rs.getString(1) : null);
        if (fkName != null) {
            runner.update(connection, "ALTER TABLE " + tableName + " DROP FOREIGN KEY " + fkName);
        } else {
            System.err.println("FK name not found");
        }
    }

    public class AlterBuilder {
        private String tableName;
        private List<Constraint> addConstrains = new ArrayList<>();

        AlterBuilder(String tableName) {
            this.tableName = tableName;
        }

        public AlterBuilder add(Constraint constraint) {
            addConstrains.add(constraint);
            return this;
        }

        /**
         * Execute created query.
         *
         * @throws SQLException the sql exception
         */
        public void execute() throws SQLException {
            StringBuilder sql = new StringBuilder("ALTER TABLE " + tableName + "\n");
            for (int i = 0; i < addConstrains.size(); i++) {
                Constraint constraint = addConstrains.get(i);
                switch (constraint.getType()) {
                case FK:
                    sql.append(format("ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s(%s) \n",
                            constraint.getConstraintName(), constraint.getField(), constraint.getReferencedTable(),
                            constraint.getReferencedField()));

                    if (constraint.getOnDeleteOpt() != null) {
                        sql.append("ON DELETE " + constraint.getOnDeleteOpt() + "\n");
                    }

                    if (constraint.getOnUpdateOpt() != null) {
                        sql.append("ON UPDATE " + constraint.getOnUpdateOpt() + "\n");
                    }
                    break;
                case PK:
                    sql.append(format("ADD CONSTRAINT %s PRIMARY KEY (%s)\n", constraint.getConstraintName(),
                            constraint.getField()));
                    break;
                case UNIQUE:
                    sql.append(format("ADD CONSTRAINT %s UNIQUE (%s)\n", constraint.getConstraintName(),
                            constraint.getField()));
                    break;
                default:
                    break;
                }

                if (i < addConstrains.size() - 1) {
                    sql.append(", \n");
                } else {
                    sql.append(";");
                }
            }

            QueryRunner runner = new QueryRunner();
            runner.update(connection, sql.toString());
        }
    }

}