sap abap開發(fā)教程培訓(xùn)intro to-chapter

1、REPORT Y170DM72.TABLES: TABNA.DATA: CNTRY LIKE TABNA-COUNTRY.SELECT DISTINCT COUNTRY FROM TABNA INTO (CNTRY).WRITE: / CNTRY.ENDSELECT.The SELECT DISTINCT StatementUsing SELECT DISTINCT, it is possible to eliminate duplicate rows from the result set.SELECT Using Aggregate FunctionsREPORT Y170DM73.TAB

2、LES: TABNA.DATA:TOTAL TYPE I,MAX_SALES LIKE TABNA-SALES,AVG_SALES LIKE TABNA-SALES,MIN_SALES LIKE TABNA-SALES.SELECTCOUNT( DISTINCT COUNTRY )MAX( SALES )AVG( SALES )MIN( SALES )FROM TABNA INTO (TOTAL, MAX_SALES, AVG_SALES, MIN_SALES)WHERE COUNTRY SPACE.WRITE: / Table TABNA Statistics, / TOTAL, Diffe

3、rent Countries, /8 MIN_SALES, Lowest Sales, /8 AVG_SALES, Average Sales, /8 MAX_SALES, Highest Sales.The Dynamic WHERE ClauseREPORT Y170DM74.TABLES: TABNA.PARAMETERS:WHERECL1(72) DEFAULT COUNTRY = USA ,WHERECL2(3) DEFAULT OR,WHERECL3(72) DEFAULT COUNTRY = GB .TYPE:BEGIN OF ITAB_RECORD, TEXT(72),END

4、OF ITAB_RECORD.DATA: WHERE_ITAB TYPE STANDARD TABLE OF ITAB_RECORD INITIAL SIZE 3 WITH HEADER LINE.WHERE_ITAB-TEXT = WHERECL1.APPEND WHERE_ITAB.WHERE_ITAB-TEXT = WHERECL2.APPEND WHERE_ITAB.WHERE_ITAB-TEXT = WHERECL3.APPEND WHERE_ITAB.SELECT * FROM TABNA WHERE (WHERE_ITAB).WRITE: / TABNA-COUNTRY, TAB

5、NA-ID.ENDSELECT.The parameters entered make up the contents of the WHERE clause. The user has the option of changing the conditions and dynamically effecting which way the program will execute.An internal table is createdwhich holds the WHERE clause until it is used in theSELECT statement.CONCATENAT

6、E StatementREPORT Y170DM74.TABLES: TABNA.PARAMETERS:WHERECL1(72) DEFAULT COUNTRY = USA ,WHERECL2(3) DEFAULT OR,WHERECL3(72) DEFAULT COUNTRY = GB .TYPE: BEGIN OF ITAB_RECORD,TEXT(72),END OF ITAB_RECORD.DATA: WHERE_ITAB TYPE STANDARD TABLE OF ITAB_RECORD INITIAL SIZE 3 WITH HEADER LINE.CONCATENATE WHE

7、RECL1 WHERECL2 WHERECL3INTO WHERE_ITAB-TEXT SEPARATED BY SPACE.APPEND WHERE_ITAB.SELECT * FROM TABNA WHERE (WHERE_ITAB).WRITE: / TABNA-COUNTRY, TABNA-ID.ENDSELECT.CONCATENATE : :INTOSEPARATED BY.Variations on the INTO ClauseREPORT Y170DM75.TABLES: TABNA.DATA:ITAB LIKE STANDARD TABLE OF TABNA INITIAL

8、 SIZE 5 WITH HEADER LINE.SELECT *FROM TABNA INTO TABLE ITAB PACKAGE SIZE 5.LOOP AT ITAB.WRITE: / ITAB-COUNTRY, ITAB-ID.ENDLOOP.ENDSELECT.SELECT * FROM INTO TABLE PACKAGE SIZE .ENDSELECT. REPORT Y170DM76.PARAMETERS: TAB_NAME(5) DEFAULT TABNA.DATA: TABLE_LINE(240).SELECT *FROM (TAB_NAME) INTO TABLE_LI

9、NE.WRITE: / TABLE_LINE.ENDSELECT.Specifying the Table Name at RuntimeJoins: Why We Should Use ThemJoins are more efficient than logical databases and nested selects.They access multiple tables with one select statement.Inner JoinsSFLIGHTSCARRInner Joins Syntax SELECT INTO () FROM INNER JOIN ON = AND

10、 = AND . . . WHERE . . . ENDSELECT.The Driving tableSELECT scarrcarrname sflightcarrid sflightconnid sflightfldate INTO (carrid, connid, date, carrname) FROM scarr INNER JOIN sflight ON scarrcarrid = sflightcarrid. WRITE: / carrid, connid, date, carrname. ENDSELECT.Left Outer JoinsSFLIGHTSCARRLeft O

11、uter Join SyntaxSELECT INTO () FROM LEFT OUTER JOIN ON = AND = AND . . . WHERE . . . ENDSELECT.Open SQL Syntax RestrictionsThe syntax for joins have been given certain restrictions in order to insure that they produce the same results for all SAP supported databases. RedundancyLFA1BSIKJoins Accessing More than Two TablesSELECT INTO () FROM ( INNER JOIN ON = AND = AND . . .) INNER JOIN ON = AND . . . WHERE . . . ENDSELECT.Aliases SELECT Acarrname Bcar