不等于:<> 判断为空的条件:null和空格(空字符串) 判断是否为null:xxxx is not null / xxxx is null 判断null: SELECT * FROM student WHERE address IS NULL ; 判断空字符串: SELECT * FROM student WHERE address=''; 包括null和空字符串: SELECT * FROM student WHERE address IS NULL OR add…
过去20年中可编程网络的发展可以分为几个阶段?每个阶段的贡献是什么? Making computer networks more programmable enables innovation in network management and lowers the barrier to deploying new services. In this section, we review early work on programmable networks. We divide the his…
为名为name的表增加数据(插入所有字段) insert into name values(1,‘张三’,‘男’,20); 为名为name的表增加数据(插入部分字段) insert into name(uid,password,money)values (2,'123456',1000); 查看名为name的表的数据(查询表中的所有数据) select * from name ; 修改表名为name的uid的字段值为2的内容为熊二(修改指定字段的值) update name set name='…
"今天学习一下FOR的语法,常用的2个语法. FOR wa|<fs> IN itab [INDEX INTO idx] [cond] "FOR i = … [THEN expr] UNTIL|WHILE log_exp DATA gs_mara TYPE mara. ROWS. *FOR wa|<fs> IN itab [INDEX INTO idx] [cond] TYPES:ty_matnr TYPE mara-matnr, ty_t_matnr TYPE…
1.语法为 CONV dTYPE|#(...)\ # 代表任意类型 "7.40之前表达式 . DATA helper TYPE string. DATA xstr TYPE xstring. helper = text. xstr = cl_abap_codepage=>convert_to( source = helper ). "7.40之后 DATA text TYPE c LENGTH 255. text = 'zhujx'. DATA(xstr1) = cl_abap_…
今天学习一下内表的表达式在ABAP 7.4之后的语法: SELECT * FROM mara INTO TABLE @DATA(gt_mara)UP TO 10 ROWS. DATA gt_mara_sort TYPE SORTED TABLE OF mara WITH UNIQUE KEY primary_key COMPONENTS matnr. "旧语法DATA LV_MATKL TYPE MARA-MATKL. INTO DATA(LS_MARA).READ TABLE gt_mara_…
