Question

我如何获得 -仅将数据库中的表计数为输出 -仅将表中的列数作为输出

Answer 1

您可以从metastore database获取此信息：

hive=> SELECT "TBL_NAME", "COLUMN_NAME", "TYPE_NAME" FROM "TBLS" , "COLUMNS_V2" WHERE "TBL_ID"="CD_ID" UNION SELECT "TBL_NAME", "PKEY_NAME", "PKEY_TYPE" FROM "PARTITION_KEYS" p , "TBLS" t WHERE p."TBL_ID"=t."TBL_ID" ORDER BY "TBL_NAME";

  TBL_NAME  | COLUMN_NAME | TYPE_NAME 
------------+-------------+-----------
 tableA     | aaa         | string
 tableA     | bbb         | string
 tableB     | foo         | string
 tableB     | bar         | int
 tableC     | cola        | string
 tableD     | colb        | string
(6 rows)

让我知道这是否有帮助。

Answer 2

hive> select count(column_name) as NoOfColumns from information_schema.columns where table_name= "TableName";

hive> select count(table_name) as NoOfTables from information_schema.tables;

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Hive-如何仅从数据库中获取表的计数作为输出

2 个答案: