S02056

S02056

For a distributed query, the TOP or LIMIT clause cannot specify an offset when used with GROUP BY/CONTEXT BY clause. RefId: S02056

在分布式查询中，LIMIT/TOP 关键字和 group by/context by 一起使用时，不支持设置起始位置。如下 case 会报错：

dbName = "dfs://test"
if (existsDatabase(dbName)) {
    dropDatabase(dbName)
}
t = table(1..3 as id)
db = database(dbName, VALUE, 1..3)
pt = db.createPartitionedTable(t, `pt, `id)
pt.append!(t)

select id from pt group by id limit 1,1

对于不符合要求的 context by 查询，目前会报另一个错误：

When LIMIT clause uses together with CONTEXT BY clause in SQL query, one can't specify row offset in LIMIT clause

根据语义改写查询语句，如上例，先将 id 列从分布式表 pt 中查询到一个临时内存表中，再对该内存表应用 limit 指定起始位置。上述查询语句可修改为：

tmp = select id from pt group by id limit 2
select * from tmp limit 1,1