open(params)

此方法使用 McoSqlOpenParameters 实参 params 打开 SmartEDB 数据库、SmartEDB SQL 映射器和 McoSqlEngine 实例。

	void open(
		&params
    );

参数

params

McoSqlOpenParameters const

初始化的McoSqlOpenParameters实例，指定内存设备页面大小和其他数据库打开参数。

返回

RuntimeException

在出现错误的情况下抛出一个 RuntimeException 异常。

示例

    const char * dbname = "RaidDb";
    const int n_devices = 5;
     
    int main(int argc, char* argv[])
    {
        MCO_RET rc;
        mco_device_t       dev[n_devices];
        McoSqlEngine engine;
        McoSqlOpenParameters params;
        ...
        dev[0].type       = MCO_MEMORY_CONV;
        dev[0].assignment = MCO_MEMORY_ASSIGN_DATABASE;
        dev[0].size       = DATABASE_SIZE;
        dev[0].dev.conv.ptr = (void*)malloc( DATABASE_SIZE );
 
        dev[1].type       = MCO_MEMORY_CONV;
        dev[1].assignment = MCO_MEMORY_ASSIGN_CACHE;
        dev[1].size       = CACHE_SIZE;
        dev[1].dev.conv.ptr = (void*)malloc( CACHE_SIZE );
         
        dev[2].type       = MCO_MEMORY_RAID;
        dev[2].assignment = MCO_MEMORY_ASSIGN_PERSISTENT;
        strcpy(dev[2].dev.raid.name, "raidpart.1");
        dev[2].dev.raid.flags = MCO_FILE_OPEN_DEFAULT;
        dev[2].dev.raid.level = 1;
 
        dev[3].type       = MCO_MEMORY_RAID;
        dev[3].assignment = MCO_MEMORY_ASSIGN_PERSISTENT;
        strcpy(dev[3].dev.raid.name, "raidpart.2");
        dev[3].dev.raid.flags = MCO_FILE_OPEN_DEFAULT;
        dev[3].dev.raid.level = 1;
         
        dev[4].type       = MCO_MEMORY_FILE;
        dev[4].assignment = MCO_MEMORY_ASSIGN_LOG;
        strcpy(dev[4].dev.file.name, "persondb.log");
        dev[4].dev.file.flags = MCO_FILE_OPEN_DEFAULT;
 
        params.databaseName = (char *)db_name;
        params.dictionary = persondb_get_dictionary();
        params.mainMemoryDatabaseSize = DATABASE_SIZE;
        params.mainMemoryPageSize = MEMORY_PAGE_SIZE;
        params.n_devices = n_devices;
        params.devices = dev;
                 
        engine.open(params);
            
        ...
    }