SELECT 语句

SELECT 是一个 Open-SQL 语句，用于将数据从一个或多个数据库表读取到数据对象中 。

1. 选择所有记录

   * This returns all records into internal table lt_mara.
   SELECT * FROM mara
            INTO lt_mara.
   

2. 选择单个记录

   * This returns single record if table consists multiple records with same key.
   SELECT SINGLE * INTO TABLE lt_mara
                   FROM mara
                   WHERE matnr EQ '400-500'.
   

3. 选择不同的记录

   * This returns records with distinct values.
   SELECT DISTINCT * FROM mara
                     INTO TABLE lt_mara
                     ORDER BY matnr.
   

4. 聚合函数

   * This puts the number of records present in table MARA into the variable lv_var 
   SELECT COUNT( * ) FROM mara
                     INTO lv_var.