apache / apache/arrow-java

[Java] Some questions about the metadata api of jdbc

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描述

### Describe the usage question you have. Please include as many useful details as possible.

When I call the `getTables` interface, I get an error
```
java.sql.SQLException: Failed to transform VectorSchemaRoot.

at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.executeForCurrentFlightStream(ArrowFlightJdbcFlightStreamResultSet.java:150)
at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.execute(ArrowFlightJdbcFlightStreamResultSet.java:139)
at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.fromFlightInfo(ArrowFlightJdbcFlightStreamResultSet.java:105)
at org.apache.arrow.driver.jdbc.ArrowDatabaseMetadata.getTables(ArrowDatabaseMetadata.java:902)
```

My server returns the result as follows
```
SELECT
TABLE_TENANT as TABLE_CAT,
TABLE_DATABASE as TABLE_SCHEM,
TABLE_NAME,
TABLE_TYPE
FROM
INFORMATION_SCHEMA.TABLES
WHERE TABLE_TENANT = 'cnosdb' AND TABLE_DATABASE LIKE 'public' AND TABLE_NAME LIKE '%' AND TABLE_TYPE IN ('TABLE')
ORDER BY
TABLE_TYPE, TABLE_CAT, TABLE_SCHEM, TABLE_NAME
```

By the code, I found that

- Convert `catalog_name` to `TABLE_CAT` in the `ArrowDatabaseMetadata.getCatalogs` api.
- Convert `db_schema_name` to `TABLE_SCHEM` in the `ArrowDatabaseMetadata.getSchemas` api.
- ......

For the above, can I think that the ResultSet Schema of my `getSchemas` implementation must be `db_schema_name`, `catalog_name` instead of `TABLE_SCHEM`, `TABLE_CATALOG`. The same goes for other API?

### Component(s)

Java

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研究方向

從 ArrowDatabaseMetadata.getTables、getSchemas 和 getCatalogs 開始,接著追蹤 ArrowFlightJdbcFlightStreamResultSet.executeForCurrentFlightStream 中的 schema 轉換。將傳回的欄位與 JDBC 中繼資料契約進行比較,並找出 getTables 結果無法轉換的原因。完成標準是記錄預期的 schema,並確認解決路徑。

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評估

技術堆疊
java
領域
api, databases
Issue 類型
缺陷
難度
4/5
預估耗時
3-5 天
活躍度
停滯
描述清晰度
需要釐清
新手友好度
25/100

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