0

阅读文档后，我仍然没有弄清楚如何将数据从内存（变量）正确写入数据集。例如，对于构造 CREATE TRUNCATE CHUNKED DATASET dsetint AS INT(UNLIMITED), "INSERT INTO dsetint (-1) VALUES (" << val << ")" ，这里没有问题，变量被替换并且记录消失。

例如 "CREATE TRUNCATE CHUNKED DATASET dsetchr AS VARCHAR(UNLIMITED)") char bl[] = "blabal"; "INSERT INTO dsetchr(-1) FROM MEMORY " << HDFql::variableRegister(&bl); 只写零

所以从问题链接中出来的例子

在输入处，我们有一个字节数组和一个数据大小在第一个数组中的数组

  uint8_t* ptr ;
    HDFql::execute("CREATE TRUNCATE FILE test.h5");
    HDFql::execute("USE FILE test.h5");

    status = HDFql::execute("CREATE TRUNCATE CHUNKED DATASET inclusion AS UNSIGNED VARTINYINT(UNLIMITED)");

    std::vector<int> s{ 6,12 };
    std::vector<uint8_t> v{0x35,0x34, 0x35, 0x00, 0x00, 0x35,0x36,0x36, 0x36, 0x36, 0x36, 0x36,0x36,0x00, 0x36, 0x00, 0x36, 0x36 };
    ptr = &v[0];

    int number = HDFql::variableRegister(&ptr);
    for (int i = 0; i < s.size();i++)
    {
        scriptst << "INSERT INTO inclusion(-1) VALUES FROM MEMORY " << number << " SIZE " << s[i];
        status = HDFql::execute(scriptst);
        ptr = ptr + s[i];
        HDFql::execute("ALTER DIMENSION Inclusions TO +1");
        scriptst.str(std::string());
        scriptst.clear();
    }
   // my expectation that there will be a record in the file
    // dataset  ->row1      0x35,0x34, 0x35, 0x00, 0x00, 0x35
    // dataset  ->row2      0x36,0x36, 0x36, 0x36, 0x36, 0x36,0x36,0x00, 0x36, 0x00, 0x36, 0x36
    // dataset  ->row3

我想从数组中将数据输入到一个没有缺陷的文件中，并能够随时附加它们。

更新 我的实验和对文档的阅读使我想到了这个例子，但它仍然不能满足我的需要。这里一个字节数组存储在数据集中，每行 1 个字节。但我仍然想在数据集行上存储一个不同长度的字节数组

status = HDFql::execute("CREATE TRUNCATE FILE test_Titnyint.h5");
    status = HDFql::execute("USE FILE test_Titnyint.h5");
    status = HDFql::execute("CREATE TRUNCATE CHUNKED DATASET inclusion AS UNSIGNED TINYINT(UNLIMITED)");
    std::vector<uint8_t> array{0x35,0x34, 0x00, 0x37, 0x35, 0x35,0x36,0x36, 0x36, 0x36, 0x00, 0x36,0x36,0x36, 0x36, 0x36, 0x36, 0x36 };
     uint8_t* ptr ;
    ptr = &array[0];
    for (int i = 0; i < array.size();i++)
    {
        int number = HDFql::variableRegister(ptr);
        if (i > 0) { status =HDFql::execute("ALTER DIMENSION inclusion TO +1"); }
        scriptst << "INSERT INTO DATASET inclusion(-1) VALUES FROM MEMORY " << number ;
        status = HDFql::execute(scriptst);
        HDFql::variableUnregister(ptr);
        ptr = ptr + 1;
        scriptst.str(std::string());
        scriptst.clear();
    }
     status = HDFql::execute("CLOSE FILE");

备注：向量“s”和“v”应该被认为是来自外部的输入。

4

1 回答 1

0

VARTINYINT要使用HDFql将可变长度数据写入 HDF5 数据集（在您的数据类型的情况下） ，您需要使用 struct 类型的变量HDFQL_VARIABLE_LENGTH。举个例子：

HDFQL_VARIABLE_LENGTH my_data;

std::vector<uint8_t> values1 {0x35,0x34, 0x35, 0x00, 0x00, 0x35};

std::vector<uint8_t> values2 {0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x00, 0x36, 0x00, 0x36, 0x36};


HDFql::execute("CREATE TRUNCATE AND USE FILE test.h5");

HDFql::execute("CREATE TRUNCATE CHUNKED DATASET inclusion AS UNSIGNED VARTINYINT(UNLIMITED)");

number = HDFql::variableRegister(&my_data);


my_data.address = values1.data();

my_data.count = values1.size();

script << "INSERT INTO inclusion(-1) VALUES FROM MEMORY " << number;

HDFql::execute(script);


my_data.address = values2.data();

my_data.count = values2.size();

HDFql::execute("ALTER DIMENSION inclusion TO +1");

HDFql::execute(script);
于 2021-12-17T01:15:57.443 回答