DQL 语法

SELECT [ hints ] [ ALL | DISTINCT ] { named_expression | star_clause } [, ...]
FROM from_item [, ...]
    [ LATERAL VIEW clause ]
    [ PIVOT clause ]
    [ WHERE clause ]
    [ GROUP BY clause ]
    [ HAVING clause]
    [ QUALIFY clause ]
​
from_item
{ table_name [ TABLESAMPLE clause ] [ table_alias ] |
    JOIN clause |
    [ LATERAL ] table_valued_function [ table_alias ] |
    VALUES clause |
    [ LATERAL ] ( query ) [ TABLESAMPLE clause ] [ table_alias ] }
​
named_expression
    expression [ column_alias ]
​
star_clause
    [ { table_name | view_name } . ] *

SELECT select_expr (, select_expr)*
FROM `Catalog`.`db`.`tableName${history|snapshots|files|manifests|partitions|all_data_files|all_manifests}`
[WHERE where_condition]
[LIMIT [offset,] rows]

SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$history` ORDER BY snapshot_id DESC LIMIT 1;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$snapshots` ORDER BY snapshot_id LIMIT 1;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$files` ORDER BY file_size_in_bytes LIMIT 1;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$manifests` ORDER BY length LIMIT 1;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$partitions` LIMIT 10;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$all_data_files` LIMIT 10;
SELECT * FROM `DataLakeCatalog`.`validation`.`dempts$all_manifests` LIMIT 10;

SELECT empno FROM sales.emp FOR SYSTEM_TIME AS OF '1986-10-26 01:21:00';
SELECT empno FROM sales.emp FOR SYSTEM_TIME AS OF 12324235546;
SELECT empno FROM sales.emp TIMESTAMP AS OF '1986-10-26 01:21:00';
SELECT empno FROM sales.emp TIMESTAMP AS OF 11111;

SELECT empno FROM sales.emp VERSION AS OF 'Snapshot123456789';
SELECT empno FROM sales.emp VERSION AS OF 11111;
SELECT empno FROM sales.emp FOR SYSTEM_VERSION AS OF 'Snapshot123456789';
SELECT empno FROM sales.emp FOR SYSTEM_VERSION AS OF 11111;

SELECT * FROM `sales`.`emp$at_timestamp_1111`；

SELECT * FROM `sales`.`emp$snapshot_id_1111`