ABAP Report根据屏幕字段，进行动态SQL查询

在写Report查询时，想根据用户输入的值动态进行数据查询，示例如下

创建选择屏幕：

SELECTION-SCREEN BEGIN OF BLOCK BLOCK1 WITH FRAME TITLE TEXT-T01.

SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_ECTYPE FOR ZTVPLM0031-ZVPLM_ER_EC_TYPE NO INTERVALS.
SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_ECID FOR ZTVPLM0031-ECR_ID NO INTERVALS.
SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_PRJID FOR ZTVPLM0031-ZPROJCODE NO INTERVALS.
SELECTION-SCREEN SKIP 1.

PARAMETERS P_STATUS TYPE ZVPLM_CMPT MODIF ID STU.
SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_LOB FOR ZTVPLM0031-ZVPLM_ER_LOB NO INTERVALS.
SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_ADATE FOR ztvplm0031-ZVPLM_REL_DATE.
SELECTION-SCREEN SKIP 1.

SELECT-OPTIONS S_CREATE FOR ZTVPLM0031-CREATED_BY NO INTERVALS.
SELECTION-SCREEN SKIP 1.

PARAMETERS P_LIMIT TYPE I DEFAULT TEXT-T07.

SELECTION-SCREEN END OF BLOCK BLOCK1.

SELECTION-SCREEN BEGIN OF BLOCK BLOCK2 WITH FRAME TITLE TEXT-T02.
SELECTION-SCREEN SKIP 1.
PARAMETERS P_CHECK AS CHECKBOX USER-COMMAND CHECK.
SELECTION-SCREEN SKIP 1.
SELECTION-SCREEN END OF BLOCK BLOCK2.

数据查询：

FORM frm_get_alv_data.
  DATA: lv_string TYPE string,

  IF s_ectype IS NOT INITIAL.   "define dynamic Sql
    lv_string = |ZVPLM_ER_EC_TYPE IN @S_ECTYPE |.
  ENDIF.

  IF s_ecid IS NOT INITIAL.
    lv_string = |{ lv_string }AND ECR_ID IN @S_ECID |.
  ENDIF.

  IF s_prjid IS NOT INITIAL.
    lv_string = |{ lv_string }AND ZPROJCODE IN @S_PRJID |.
  ENDIF.

  IF p_status IS NOT INITIAL.
    lv_string = |{ lv_string }AND ( ZVPLM_CMPT = @P_STATUS OR ZVPLM_CMPT = '' ) |.
  ENDIF.

  IF s_lob IS NOT INITIAL.
    lv_string = |{ lv_string }AND ZVPLM_ER_LOB IN @S_LOB |.
  ENDIF.

  IF s_adate IS NOT INITIAL..
    lv_string = |{ lv_string }AND ZVPLM_REL_DATE IN @S_ADATE |.
  ENDIF.

  IF s_create IS NOT INITIAL.
    lv_string = |{ lv_string }AND CREATED_BY IN @S_CREATE |.
  ENDIF.

  IF p_check = 'X'.
    IF gv_moduser = TEXT-T11.
      lv_string = |{ lv_string }AND ZVPLM_UIPQC = '' |.
    ENDIF.

    IF gv_moduser = TEXT-T12.
      lv_string = |{ lv_string }AND ZVPLM_UIPQC <> '' AND ZVPLM_UPQE = '' |.
    ENDIF.
  ENDIF.

  IF lv_string IS INITIAL.
    SELECT * FROM ztvplm0031 INTO TABLE @gt_alvshow1[] UP TO @p_limit ROWS. "Undefined Query Conditions
    IF gt_alvshow1 IS INITIAL.
      MESSAGE |没有记录找到| TYPE 'S'.
    ELSE.
      gt_alvshow2 = gt_alvshow1.
    ENDIF.
  ELSE.
    IF lv_string+0(3) = 'AND'.
      lv_string = lv_string+4(*).   "Del Home "AND"
    ENDIF.
    SELECT * FROM ztvplm0031 WHERE (lv_string) INTO TABLE @gt_alvshow1[] UP TO @p_limit ROWS. "Dynamic Query
    IF gt_alvshow1 IS INITIAL.
      MESSAGE |没有记录找到| TYPE 'S'.
    ELSE.
      gt_alvshow2 = gt_alvshow1.
    ENDIF.
  ENDIF.
ENDFORM.