ABAP语法笔记07 - SELECT
" 基本的查询语句 " 从表中满足条件的数据,按GT字段顺序放入数据(字段信息不匹配会取值错误) SELECT FIELDNAME FROM TAB_NAME INTO TABLE GT WHERE expression . " 添加 CORRESPONDING FIELDS OF 后表示对应字段插入数据 SELECT FIELDNAME FROM TAB_NAME INTO CORRESPONDING FIELDS OF TABLE GT WHERE expression . " 查询单条数据 SELECT SINGLE FIELDNAME FROM TAB_NAME INTO LS " 当使用TABLES声明后,这里的INTO可以省略,默认取数到TABLES声明的结构中 WHERE expression .
" 多表联合查询 " INNER JOIN 关联调节写在ON上,限制条件写WHERE SELECT A~FIELD1 B~FIELD2 FROM TAB1 AS A INNER JOIN TAB2 AS B ON A~KEY = B~KEY INTO CORRESPONDING FIELDS OF TABLE GT WHERE A~FIELD3 IN S_FIELD3 AND B~FIELD4 IN S_FIELD4 . " LEFT OUTER JOIN 左表条件写在WHERE 右表写在ON上 SELECT A~FIELD1 B~FIELD2 FROM TAB1 AS A LEFT OUTER JOIN TAB2 AS B ON A~KEY = B~KEY AND B~FIELD4 IN S_FIELD4 INTO CORRESPONDING FIELDS OF TABLE GT WHERE A~FIELD3 IN S_FIELD3 .
" 摘录网上说明: " 多表查询时,主键使用JOIN链接似乎更合适,其他情况下内表处理效率更高 " FOR ALL ENTRIES IN 效率比JOIN 还低 " CORRESPONDING FIELDS OF 会影响效率 SELECT A~FIELD1 FROM TAB1 AS A INTO CORRESPONDING FIELDS OF TABLE GT WHERE A~FIELD3 IN S_FIELD3 . SELECT B~FIELD2 FROM TAB2 AS B INTO CORRESPONDING FIELDS OF TABLE GT FOR ALL ENTRIES IN GT WHERE B~KEY EQ GT-KEY AND B~FIELD4 IN S_FIELD4 .
RANGES R_FIELD FOR TAB_NAME . " 声明一个带表头行的范围变量
post SAP-Garson
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