WHERE IN 条件不接受字符串值

问题描述

我在 PL/Sql 过程中通过附加 USERNAME、单引号 (') 和逗号 (,) 的形式动态构造一个名为 user_data 的字符串

I am dynamically constructing a string with name user_data in PL/Sql procedure by appending USERNAMEs, single quotes(') and commas(,) of the form

'abc123','xyz456','pqr789'

但是当我将此字符串传递给 SELECT 语句的 WHERE IN 条件时

But when I pass this string to WHERE IN condition of SELECT statement

SELECT * FROM table_name WHERE USERNAME IN (user_data)

它正在抛出一个 NO_DATA_FOUND 异常.

It is throwing a NO_DATA_FOUND exception.

另一方面，如果我的字符串只包含一个没有引号的用户，它能够找到该用户并显示所需的输出.

On the other hand if my string contains only one user without the quotes, it is able to find that user and display desired output.

字符串user_data的数据类型是varchar2.

The datatype of string user_data is varchar2.

推荐答案

您可以使用集合来完成:

You can do it using a collection:

CREATE TYPE VARCHAR2s_Table IS TABLE OF VARCHAR2(100);
/

然后像这样输入您的数据:

Then enter your data like this:

SELECT *
FROM   table_name
WHERE  user_data MEMBER OF VARCHAR2s_Table( 'abc123','xyz456','pqr789' );

或者:

您可以创建一个函数来拆分数据并生成集合:

You can create a function to split the data and generate the collection:

CREATE TYPE VARCHAR2_TABLE AS TABLE OF VARCHAR2(4000);
/

CREATE OR REPLACE FUNCTION split_String(
  i_str    IN  VARCHAR2,
  i_delim  IN  VARCHAR2 DEFAULT ','
) RETURN VARCHAR2_TABLE DETERMINISTIC
AS
  p_result       VARCHAR2_TABLE := VARCHAR2_TABLE();
  p_start        NUMBER(5) := 1;
  p_end          NUMBER(5);
  c_len CONSTANT NUMBER(5) := LENGTH( i_str );
  c_ld  CONSTANT NUMBER(5) := LENGTH( i_delim );
BEGIN
  IF c_len > 0 THEN
    p_end := INSTR( i_str, i_delim, p_start );
    WHILE p_end > 0 LOOP
      p_result.EXTEND;
      p_result( p_result.COUNT ) := SUBSTR( i_str, p_start, p_end - p_start );
      p_start := p_end + c_ld;
      p_end := INSTR( i_str, i_delim, p_start );
    END LOOP;
    IF p_start <= c_len + 1 THEN
      p_result.EXTEND;
      p_result( p_result.COUNT ) := SUBSTR( i_str, p_start, c_len - p_start + 1 );
    END IF;
  END IF;
  RETURN p_result;
END;
/

然后你可以这样做:

SELECT *
FROM   table_name
WHERE  user_data MEMBER OF split_String( 'abc123,xyz456,pqr789', ',' );

或:

SELECT *
FROM   table_name
WHERE  user_data MEMBER OF split_String( TRIM( '''' FROM '''abc123'',''xyz456'',''pqr789''' ), ''',''' );

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