Question

我试图运行以下代码：

SQLSMALLINT** column_types = new SQLSMALLINT*[*ColumnCount];


void** ColumnsData = new void*[*ColumnCount];

SQLINTEGER** rowLengths = new SQLINTEGER*[*ColumnCount];

int limit = *ColumnCount;
for(int i=0;i<limit;i++)
{
    column_types[i] = new SQLSMALLINT();
     SQLColAttribute(hStmt,i+1,SQL_DESC_TYPE,NULL,NULL,NULL,(SQLPOINTER)column_types[i]);
     SQLSMALLINT type = *column_types[i];
     switch(type)
     {
     case SQL_CHAR:

             ColumnsData[i] = new SQLCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLCHAR**)ColumnsData[i])[l] = new SQLCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_CHAR,ColumnsData[i],512,rowLengths[i]);
            break; //<<<<<<<<<<<<<<<<<<<<<<<<<<<

     case SQL_VARCHAR:

             ColumnsData[i] = new SQLCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLCHAR**)ColumnsData[i])[l] = new SQLCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_VARCHAR,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_LONGVARCHAR:

             ColumnsData[i] = new SQLCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLCHAR**)ColumnsData[i])[l] = new SQLCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_LONGVARCHAR,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_WCHAR:

             ColumnsData[i] = new SQLWCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLWCHAR**)ColumnsData[i])[l] = new SQLWCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_WCHAR,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_WVARCHAR:

             ColumnsData[i] = new SQLWCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLWCHAR**)ColumnsData[i])[l] = new SQLWCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_WVARCHAR,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_WLONGVARCHAR:

             ColumnsData[i] = new SQLWCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLWCHAR**)ColumnsData[i])[l] = new SQLWCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_WLONGVARCHAR,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_DECIMAL:

             ColumnsData[i] = new SQL_NUMERIC_STRUCT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_DECIMAL,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_NUMERIC:

             ColumnsData[i] = new SQL_NUMERIC_STRUCT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_NUMERIC,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_SMALLINT:

             ColumnsData[i] = new SQLSMALLINT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_SMALLINT,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_INTEGER:

            ColumnsData[i] = new SQLINTEGER[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_INTEGER,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_REAL:

             ColumnsData[i] = new SQLREAL[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_REAL,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_FLOAT:

             ColumnsData[i] = new SQLREAL[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_FLOAT,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_DOUBLE:

             ColumnsData[i] = new SQLDOUBLE[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_DOUBLE,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_BIT:

             ColumnsData[i] = new SQLCHAR[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_BIT,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_TINYINT:

             ColumnsData[i] = new SQLSCHAR[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_TINYINT,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_BIGINT:

             ColumnsData[i] = new SQLBIGINT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_BIGINT,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_BINARY:

             ColumnsData[i] = new SQLCHAR**[*RowCount];
             for(int l=0;l<*RowCount;l++)
             {
                 ((SQLCHAR**)ColumnsData[i])[l] = new SQLCHAR[512];
             }

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_BINARY,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_TYPE_DATE:

            ColumnsData[i] = new SQL_DATE_STRUCT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

//>>>>>>>>>>>>>>>
             SQLBindCol(hStmt,i+1,SQL_TYPE_DATE,ColumnsData[i],512,rowLengths[i]);
             break;

     case SQL_TYPE_TIME:

             ColumnsData[i] = new SQL_TIME_STRUCT[*RowCount];

             rowLengths[i] = new SQLINTEGER[*RowCount];

             SQLBindCol(hStmt,i+1,SQL_TYPE_TIME,ColumnsData[i],512,rowLengths[i]);
             break;

     default:

             break;

     }
}

当它遇到SQL_CHAR并且在SQLBindcol调用之前跳转到case SQL_TYPE_DATE时，它是如何可能的，是故障还是我在这里做错了，因为break应该退出交换机

Answer 1

我将假设您在某种调试器中看到了这种行为，并且我将假设您构建了一个优化的构建。在这种情况下，您所看到的是优化器重用代码 - 优化器通常会使调试变得有些困难，因此只需进行一次未经优化的构建。

如果你真的没有启用优化，我会尝试的第一件事是进行完全清理/重建（仍然没有优化），以确保你有一个一致的基础测试。

Answer 2

我假设您是这样说的，因为通过调试器检查代码。尝试在编译期间禁用优化。

Answer 3

我建议除SQL_CHAR以外的所有其他切换案例，并查看会发生什么。如果调试器进入注释掉的代码，则必须进行优化。如果出现这种情况，请一次添加其他一个案例，并查看问题何时重新出现。这将缩小问题的原因。

在c ++中切换故障如何？

3 个答案: