CockroachDBTable.java

/*-
 * ========================LICENSE_START=================================
 * flyway-database-postgresql
 * ========================================================================
 * Copyright (C) 2010 - 2026 Red Gate Software Ltd
 * ========================================================================
 * 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.
 * =========================LICENSE_END==================================
 */
package org.flywaydb.database.cockroachdb;

import org.flywaydb.core.internal.database.InsertRowLock;
import org.flywaydb.core.internal.database.base.Table;
import org.flywaydb.core.internal.jdbc.JdbcTemplate;
import org.flywaydb.core.internal.util.SqlCallable;

import java.sql.SQLException;

/**
 * CockroachDB-specific table.
 * <p>
 * Note that CockroachDB doesn't support table locks. We therefore use a row in the schema history as a lock indicator;
 * if another process has inserted such a row we wait (potentially indefinitely) for it to be removed before carrying
 * out a migration.
 */
public class CockroachDBTable extends Table<CockroachDBDatabase, CockroachDBSchema> {
    private final InsertRowLock insertRowLock;

    CockroachDBTable(final JdbcTemplate jdbcTemplate,
        final CockroachDBDatabase database,
        final CockroachDBSchema schema,
        final String name) {
        super(jdbcTemplate, database, schema, name);
        this.insertRowLock = new InsertRowLock(jdbcTemplate);
    }

    @Override
    protected void doDrop() throws SQLException {
        new CockroachDBRetryingStrategy().execute((SqlCallable<Integer>) () -> {
            doDropOnce();
            return null;
        });
    }

    protected void doDropOnce() throws SQLException {
        jdbcTemplate.execute("DROP TABLE IF EXISTS " + database.quote(schema.getName(), name) + " CASCADE");
    }

    @Override
    protected boolean doExists() throws SQLException {
        return new CockroachDBRetryingStrategy().execute(this::doExistsOnce);
    }

    protected boolean doExistsOnce() throws SQLException {
        if (schema.cockroachDB1) {
            return jdbcTemplate.queryForBoolean("SELECT EXISTS (\n"
                + "   SELECT 1\n"
                + "   FROM   information_schema.tables \n"
                + "   WHERE  table_schema = ?\n"
                + "   AND    table_name = ?\n"
                + ")", schema.getName(), name);
        } else if (!schema.hasSchemaSupport) {
            return jdbcTemplate.queryForBoolean("SELECT EXISTS (\n"
                + "   SELECT 1\n"
                + "   FROM   information_schema.tables \n"
                + "   WHERE  table_catalog = ?\n"
                + "   AND    table_schema = 'public'\n"
                + "   AND    table_name = ?\n"
                + ")", schema.getName(), name);
        } else {
            // There is a bug in CockroachDB v20.2.0-beta.* which causes the string equality operator to not work as
            // expected, therefore we apply a workaround using the like operator.
            // https://github.com/cockroachdb/cockroach/issues/55437
            final String sql = "SELECT EXISTS (\n"
                + "   SELECT 1\n"
                + "   FROM   information_schema.tables \n"
                + "   WHERE  table_schema = ?\n"
                + "   AND    table_name like '%"
                + name
                + "%' and length(table_name) = length(?)\n"
                + ")";
            return jdbcTemplate.queryForBoolean(sql, schema.getName(), name);
        }
    }

    @Override
    protected void doLock() throws SQLException {
        final String updateLockStatement = "UPDATE "
            + this
            + " SET installed_on = now() WHERE version = '?' AND DESCRIPTION = 'flyway-lock'";
        final String deleteExpiredLockStatement = " DELETE FROM "
            + this
            + " WHERE DESCRIPTION = 'flyway-lock'"
            + " AND installed_on < TIMESTAMP '?'";

        if (lockDepth == 0) {
            insertRowLock.doLock(database.getInsertStatement(this),
                updateLockStatement,
                deleteExpiredLockStatement,
                database.getBooleanTrue());
        }
    }

    @Override
    protected void doUnlock() throws SQLException {
        if (lockDepth == 1) {
            insertRowLock.doUnlock(getDeleteLockTemplate());
        }
    }

    private String getDeleteLockTemplate() {
        return "DELETE FROM " + this + " WHERE version = '?' AND DESCRIPTION = 'flyway-lock'";
    }
}