在 Oracle 12c 中使用 CLOB 时字符串连接的结果太长

Question

我在使用 CLOB 字段时遇到 "result of string concatenation is too long" 错误。结果字段是

varSQLConcat CLOB;

拼接语句为

varSQLConcat := CONCAT(TO_CLOB(varSel_CREATION), TO_CLOB(varWhere_New));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' AND SY_INPUT_UID_NEW.SUBMISSION_TYPE = '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB('''CREATION'''));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' UNION '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varSel_SUBMISSION));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varWhere_New));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' AND (SY_INPUT_UID_NEW.SUBMISSION_TYPE = '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB('''SUBMISSION'''));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB('OR SY_INPUT_UID_NEW.SUBMISSION_TYPE = '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB('''NEW_W_REG_PARENT'')'));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' UNION '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varSel_ROLLOVER));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varWhere_Rollover));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' UNION '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varSel_EMBED));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varWhere_Embed));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' UNION '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varSel_LIFECYCLE));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varWhere_Lifecycle));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(' UNION '));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varSel_MARK));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varWhere_Mark));
   varSQLConcat := CONCAT(varSQLConcat, TO_CLOB(varOrder_By));

以下语句出现错误：

OPEN cRecord FOR varSQLConcat;

这是在 Oracle 12c 下。

Answer 1

我没有真正的解决方案，但这可能是一个解决方法：

DECALRE

    cmd DBMS_SQL.VARCHAR2A;
    cur PLS_INTEGER := DBMS_SQL.OPEN_CURSOR;
    res INTEGER;
    cRecord := SYS_REFCURSOR;

BEGIN
    cmd(1) := varSel_CREATION; -- each line is limited by 32767 characters!
    cmd(cmd.LAST+1) := varWhere_New;
    cmd(cmd.LAST+1) := 'AND SY_INPUT_UID_NEW.SUBMISSION_TYPE = ';
    cmd(cmd.LAST+1) := '''CREATION'''; 
    ...


    DBMS_SQL.PARSE(cur, cmd, cmd.FIRST, cmd.LAST, TRUE, DBMS_SQL.NATIVE); 
    res := DBMS_SQL.EXECUTE(cur);   
    cRecord := DBMS_SQL.TO_REFCURSOR(cur);

END;

在 Oracle 12c 中使用 CLOB 时字符串连接的结果太长

Result of string concatenation is too long when using CLOB in Oracle 12c

string

oracle

clob

long-integer