SQLファイルとしてTsurugi上のテーブルデータをダンプするコード

TsurugiSqlDumper.java

package com.example.tsurugi;

import com.tsurugidb.iceaxe.TsurugiConnector;
import com.tsurugidb.iceaxe.session.TsurugiSession;
import com.tsurugidb.iceaxe.sql.result.TsurugiResultEntity;
import com.tsurugidb.iceaxe.transaction.option.TgTxOption;
import com.tsurugidb.sql.proto.SqlCommon;

import java.io.PrintWriter;
import java.math.BigDecimal;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

import static java.nio.file.StandardOpenOption.*;

public class TsurugiSqlDumper {

    private final URI dbUrl;

    private final String tableName;

    private final Path outputDir;

    public TsurugiSqlDumper(URI dbUrl, String tableName, Path outputDir) {
        this.dbUrl = dbUrl;
        this.tableName = tableName;
        this.outputDir = outputDir;
    }

    public void dump() throws Exception {
        var fileName = "insert_" + tableName + ".sql";
        var filePath = outputDir.resolve(fileName);
        var connector = TsurugiConnector.of(dbUrl);
        var sql = "select * from " + tableName;
        try (TsurugiSession session = connector.createSession();
                var writer = new PrintWriter(Files.newBufferedWriter(filePath, WRITE, CREATE, TRUNCATE_EXISTING))) {
            writer.println("start long transaction write preserve " + tableName + ";");

            var metadata = session.findTableMetadata(tableName).orElseThrow();
            List<? extends SqlCommon.Column> columnList = metadata.getLowColumnList();
            var columnNameList = columnList.stream().map(SqlCommon.Column::getName).toList();

            var tm = session.createTransactionManager(TgTxOption.ofRTX());
            var resultList = tm.executeAndGetList(sql);
            for (TsurugiResultEntity entity : resultList) {
                var builder = new StringBuilder("insert or replace into ");
                builder.append(tableName).append(" (").append(String.join(",", columnNameList)).append(") values (");
                var valuesString = columnList.stream().map(column -> getValueString(entity, column)).toList();
                builder.append(String.join(",", valuesString)).append(");");
                writer.println(builder);
            }
            writer.println("commit;");
        }
    }

    private String getValueString(TsurugiResultEntity entity, SqlCommon.Column column) {
        var atomType = column.getAtomType();
        var columnName = column.getName();
        return switch (atomType) {
            case INT4 -> entity.findInt(columnName).map(value -> Integer.toString(value)).orElse("NULL");
            case INT8 -> entity.findLong(columnName).map(value -> Long.toString(value)).orElse("NULL");
            case FLOAT4 -> entity.findFloat(columnName).map(value -> Float.toString(value)).orElse("NULL");
            case FLOAT8 -> entity.findDouble(columnName).map(value -> Double.toString(value)).orElse("NULL");
            case DECIMAL -> entity.findDecimal(columnName).map(BigDecimal::toPlainString).orElse("NULL");
            case CHARACTER -> entity.findString(columnName).map(value -> "'" + value + "'").orElse("NULL");
            case DATE -> entity.findDate(columnName).map(value -> "date '" + value + "'").orElse("NULL");
            case TIME_POINT -> entity.findDateTime(columnName).map(value -> "timestamp '" + value + "'").orElse("NULL");
            case TIME_POINT_WITH_TIME_ZONE ->
                    entity.findOffsetDateTime(columnName).map(value -> "timestamp with time zone '" + value + "'")
                            .orElse("NULL");
            default -> "NULL";
        };
    }

}