查询引擎: SQL反解析(json2sql)(附源码)

目录

1.前言

2.主要设计

1.请求体

2.构建Table

3.使用

4.自定义过滤条件

5.自定义聚合指标

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1.前言

1.业务人员不懂SQL，通过UI自助查询关系型数据库；支持单表过滤、分组、排序、聚合指标、limit；

2.过滤条件包含：between、like、=、!=、>、>=、<、<=等

3.聚合指标包含：count、max、min、sum等

 

2.主要设计

1.请求体

1.QueryRequest

    private List<RequestElementMeasure> measures;
    private String table;
    private RequestElementFilter filter;
    private List<String> groupByList;
    private List<Integer> orderByList;
    private Long limit;

2.RequestElementMeasure

    private String field;
    private String aggregator;
    private List<Object> params;

3.RequestElementFilter

private String relation;
private List<RequestElementCondition> conditions;
private List<RequestElementFilter> filters;

2.构建Table

    protected String tableName;
    protected List<AbstractColumn> columns = new ArrayList<>();
    private AbstractFilter filter;
    private List<String> groupByList;
    private List<Integer> orderByList;
    protected Limit limit;

 

3.使用

String requestJson = "{\"limit\":10,\"orderByList\":[1],\"groupByList\":[\"name\"],\"filter\":{\"and\":true,\"conditions\":[{\"field\":\"age\",\"function\":\"equal\",\"params\":[20]}]},\"measures\":[{\"aggregator\":\"count\",\"field\":\"age\"}],\"table\":\"person\"}";
        QueryRequest request = JSONObject.parseObject(requestJson, QueryRequest.class);

        AliasGenerator aliasGenerator = new AliasGenerator();
        Table table = new Table(request.getTable());

        for (String groupBy : request.getGroupByList()) {
            table.addSelect(new AtomColumn(groupBy, aliasGenerator.nextAlias()));
        }
        request.getMeasures().forEach(measure -> {
            ExpressionColumn expressionColumn = TableUtil.constructAggregation(measure, aliasGenerator.nextAlias());
            table.addSelect(expressionColumn);
        });

        RequestElementFilter filter = request.getFilter();
        CompoundFilter compoundFilter = new CompoundFilter();
        compoundFilter.setIsAnd(filter.isAnd());
        for (RequestElementCondition condition : filter.getConditions()) {
            AbstractColumn column = new AtomColumn(condition.getField(), aliasGenerator.nextAlias());
            compoundFilter.addSubFilter(FilterUtil.getFunctionCondition(condition.getField(), condition.getFunction(), condition.getParams())
                    .createFilter(column));
        }
        table.setFilter(compoundFilter);
        table.setGroupByList(request.getGroupByList());
        table.setOrderByList(request.getOrderByList());
        table.setLimit(new Limit(request.getLimit()));
        System.out.println(">>>" + table.constructSql());

 

4.自定义过滤条件

1.定义FunctionCondition(参考GreaterCondition)
2.定义SimpleFilter(参考Greater)

5.自定义聚合指标

1.定义ExecutableExpression(参考Max)
2.添加AggregatorType
3.添加TableUtil

6.源码地址

https://github.com/ostarsier/queryengine