private String genLoadNodeInsertSql(LoadNode loadNode, NodeRelation relation, Map<String, Node> nodeMap) {
        Preconditions.checkNotNull(loadNode.getFieldRelations(), "field relations is null");
        Preconditions.checkState(!loadNode.getFieldRelations().isEmpty(),
                "field relations is empty");
        String selectSql = genLoadSelectSql(loadNode, relation, nodeMap);
        return "INSERT INTO `" + loadNode.genTableName() + "`\n    " + selectSql;
    }
Generate load node insert sql

@param loadNode The real data write node
@param relation The relation between nods
@param nodeMap The node map
@return Insert sql
inlong-sort/sort-core/src/main/java/org/apache/inlong/sort/parser/impl/FlinkSqlParser.java