sql血缘关系解析

最新推荐文章于 2025-06-29 09:25:41 发布

漫天沙尘

最新推荐文章于 2025-06-29 09:25:41 发布

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本文链接：https://blog.youkuaiyun.com/qq_28725695/article/details/81904778

sql

create table default.target_table LOCATION '/data/location' as select a,b,d,e,f,g from log.source_table

生成的ast树

(TOK_CREATETABLE (TOK_TABNAME default target_table) TOK_LIKETABLE (TOK_TABLELOCATION '/data/location') (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME log source_table))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL a)) (TOK_SELEXPR (TOK_TABLE_OR_COL b)) (TOK_SELEXPR (TOK_TABLE_OR_COL d)) (TOK_SELEXPR (TOK_TABLE_OR_COL e)) (TOK_SELEXPR (TOK_TABLE_OR_COL f)) (TOK_SELEXPR (TOK_TABLE_OR_COL g)))))) <EOF>

树结构

这里写图片描述

解析过程

调用org.apache.hadoop.hive.ql.parse的ParseDriver的parse方法，生成sql的ast树
后序遍历ast树
解析每个节点

结果

inputTable:[log.source_table]
outputTable:[default.target_table]
ToTable:default.target_table,ToNameParse:a,ToName:null,FromName:[log.source_table.a],AllCondition:[]
ToTable:default.target_table,ToNameParse:b,ToName:null,FromName:[log.source_table.b],AllCondition:[]
ToTable:default.target_table,ToNameParse:d,ToName:null,FromName:[log.source_table.d],AllCondition:[]
ToTable:default.target_table,ToNameParse:e,ToName:null,FromName:[log.source_table.e],AllCondition:[]
ToTable:default.target_table,ToNameParse:f,ToName:null,FromName:[log.source_table.f],AllCondition:[]
ToTable:default.target_table,ToNameParse:g,ToName:null,FromName:[log.source_table.g],AllCondition:[]