Complex queries may appear similar to abnormal, sometimes you might be in view is created, it may be the following errors:
Code: 352. DB::Exception: Received from localhost:9000. DB::Exception: Cannot refer column '表名.字段名' to table.
First clickhouse usage exists is not supported in the current version (version 19.17.4.11), if you encounter a usage exists, it should be changed in syntax.
Because the query is more complex, this whole complex query can query in mysql, which is part of the nested statements can also query in mysql and clickhouse in.
But the overall complexity of the query but not in clickhouse query, will report suggested above error.
Wherein nested query with a plurality of internal tables and join with the inner join conditions on (table. Column name = name table 1. Column 1) multi-table joins, etc.
The final solution:
The internal inquiry separately taken out to create a separate small view.
Then
the
original complex queries overall internal nested queries replaced these small view, the whole complex will become a simple query, and then run this query, it will not report the mistake.