Question

我有3个输入参数，根据每个输入参数的值，我必须动态地在程序中准备SQL。我正在以下方式但它失败了，如果参数值为null，那么我必须从where子句中排除它。

IN参数：

在varchar2 ||中empname IN varchar2 || emps in varchar2

SELECT
      EMP_NAME
INTO
      V_EMP_NAME
FROM
      EMPLOYEE
WHERE
         ( EMP_ID = EMPID
          OR ( EMP_ID IS NULL
             AND EMPID IS NULL ) )
      AND ( EMP_NAME = EMPNAME
          OR ( EMP_NAME IS NULL
             AND EMPNAME IS NULL ) )
      AND ( EMP_SAL = EMPSAL
          OR ( EMP_SAL IS NULL
             AND EMPSAL IS NULL ) );

更新后我修改了如下所示的查询，它被编译但是给出了运行时错误，说ORA-00933：SQL命令在EXECUTE IMMEDIATE之前没有正确结束

  V_SQL :='SELECT EMP_NAME INTO V_empname FROM employee WHERE ';
    BEGIN
    IF(EMPID IS NOT NULL) THEN
     V_SQL := V_SQL || ' emp_id='||EMPID;
    END IF; 
    IF(EMPNAME IS NOT NULL) THEN
      V_SQL := V_SQL || ' AND emp_name='||EMPNAME;
    END IF; 
    IF(V_empsalIS NOT NULL) THEN
      V_SQL := V_SQL || ' AND  emp_sal='||empsal;
 V_SQL := V_SQL ||' AND ACTIVE =''Y''' ;
    END IF; 
        EXECUTE IMMEDIATE V_SQL;
  EXCEPTION
    WHEN NO_DATA_FOUND THEN
      V_check:= '' ;
    END;

Answer 1

这是另一种选择：

V_SQL_WHERE := null;

  V_SQL :='SELECT EMP_NAME INTO V_empname FROM employee';
    BEGIN

    IF(EMPID IS NOT NULL) THEN
      V_SQL_WHERE := V_SQL_WHERE || ' emp_id='||EMPID;
    END IF; 

    IF(EMPNAME IS NOT NULL) THEN

      IF (V_SQL_WHERE is not null) THEN 
        V_SQL_WHERE := V_SQL_WHERE || ' AND ';
      END IF;

      V_SQL_WHERE := V_SQL_WHERE || ' emp_name='||EMPNAME;
    END IF; 

    IF(V_empsalIS NOT NULL) THEN

      IF (V_SQL_WHERE is not null) THEN 
         V_SQL_WHERE := V_SQL_WHERE || ' AND ';
      END IF; 
      V_SQL_WHERE := V_SQL_WHERE || ' emp_sal=' || empsal;
      V_SQL_WHERE := V_SQL_WHERE || ' AND ACTIVE =''Y''' ;

    END IF; 

    IF (V_SQL_WHERE is not null) then
      V_SQL := V_SQL || ' WHERE ' || V_SQL_WHERE;
    end if;

        EXECUTE IMMEDIATE V_SQL;
  EXCEPTION
    WHEN NO_DATA_FOUND THEN
      V_check:= '' ;
    END;

Answer 2

您可以从头开始创建一个，包括if和elses，或者您可以使用名为plsql-utils的包SQL_BUILDER_PKG。它为你完成了整个工作。

查看 SQL实用程序

http://code.google.com/p/plsql-utils/

例如：

declare
  l_my_query sql_builder_pkg.t_query;
  l_sql varchar2(32000);
begin

  sql_builder_pkg.add_select (l_my_query, 'ename');
  sql_builder_pkg.add_select (l_my_query, 'sal');
  sql_builder_pkg.add_select (l_my_query, 'deptno');
  sql_builder_pkg.add_from (l_my_query, 'emp');
  sql_builder_pkg.add_where (l_my_query, 'ename = :p_ename');
  sql_builder_pkg.add_where (l_my_query, 'sal > :p_sal');
  l_sql := sql_builder_pkg.get_sql (l_my_query);
  dbms_output.put_line (l_sql);
end;

我在一个项目中使用它，这是一个很好的工具。

Answer 3

这样的事情:(没有经过测试，只是一个想法）

BEGIN
    IF EMPID IS NOT NULL
    THEN
        CLAUSE1   := 'EMP_ID = EMPID';
    ELSE
        CLAUSE1   := '1=1';
    END IF;

    IF EMPNAME IS NOT NULL
    THEN
        CLAUSE2   := 'EMP_NAME = EMPNAME';
    ELSE
        CLAUSE2   := '1=1';
    END IF;

    IF EMPSAL IS NOT NULL
    THEN
        CLAUSE3   := 'EMP_SAL = EMPSAL';
    ELSE
        CLAUSE3   := '1=1';
    END IF;

    IF (    EMPSAL IS NULL
        AND EMPNAME IS NULL
        AND EMPID IS NOT NULL )
    THEN
        CLAUSE1   := '1=0';
        CLAUSE2   := '1=0';

        CLAUSE3   := '1=0';
    END IF;

    QUERY_STR   :=
           '    SELECT EMP_NAME INTO V_EMP_NAME FROM EMPLOYEE WHERE'
        || CLAUSE1
        || ' AND '
        || CLAUSE2
        || ' AND '
        || CLAUSE3;
END;

在oracle存储过程中动态准备sql

3 个答案: