ABAP-01 BASIS CONCEPT

1. Repository & dictionary的差異
	All programs are stored in the R/3 Repository =>A program is simply an object.
	All definitions are kept in the data dictionary =>.e.g. variable descriptions and parameters of fields.
1.1 The ABAP/4 Dictionary is the central facility in the system where you can create and maintain data declarations, tables, structures and aggregated objects.
1.2 Since it is integrated into the ABAP/4 Development Workbench as an active component, any change made in the ABAP/4 Dictionary takes immediate effect in programs affected.
1.3分為三大type filed type=>data element/transparent field structure type=>structure/transparent table table type=>internal table
2. An ABAP/4 program consists of individual statements
2.1 Each statement must end with a period(.)
2.2 The first word of a statement is known as the key word.
2.3 Words are separated from each other by at least one blank.
2.4 Statements can be indented.
2.5 Statements can extend over several lines.
3. You can concatenate several consecutive statements with an identical key word (e.g. WRITE: ).
3.1 Follow the key word with a colon(:)
3.2 Separate each concatenated part with a comma.
3.3 End the lines of the concatenated statements with a period.
4.You can insert comments into a program in two ways:
	An asterisk (*) in column 1 flags the whole line as a comment. A quotation mark (“) within a line flags the remainder of the line as a comment.
5. A quotation mark (“) within a line flags the remainder of the line as a comment.
	Double-clicking on the Tables: statement in the editor will display how the table is defined in the data dictionary.
6. ABAP 數據類型及定義
	C=>字元型態,預設長度1,最大長度無限制,預設值是空白 (所以下sql語法進db拉資料時需轉為=' ') N=>數字型態,預設長度1,最大長度無限制,不可進行運算,如電話 F=>Floatiog Point P=>Packed,相似於數字型態,預設長度1,預設值為零,最大長度為16位,如金額 I=>整數型態,預設長度1,預設值是零,此類型的數字才可進行數值運算 D=>日期型態,標準長度固定為8位,格式為YYYYMMDD T=>時間型態,標準長度固定為6位,格式為HHMMSS X=>16進位,預設長度為2,預設值為零零,最大長度無限制
7.OTHER
DAILOG 就算你是Z/Y開頭 但是SAP會加前置SAP SA38可直接執行PROGRAM 不能修改 data **** WITH HEADER LINE ==>INTAB+ WA tables ==>wa funcation group==>??? update==> 單純update modify==>找不到就insert cs_bOM_EXPL_MAT_V2==>EXP BOM