public static String getDatabaseNameFromIdentifier(String tableIdentifier) {
        String[] fileArray = tableIdentifier.split("\\.");
        return fileArray[0];
    }
Get database name From tableIdentifier
tableIdentifier maybe: ${dbName}.${tbName} or ${dbName}.${schemaName}.${tbName}

@param tableIdentifier The table identifier for which to get table name.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/jdbc/src/main/java/org/apache/inlong/sort/jdbc/internal/JdbcMultiBatchingComm.java