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mcTBload, mcTBloadAll — Load relational table
#include <memcom.h>
mcRTable* mcTBload(int handle, const char* name, mcOff idiv);
mcRTable* rt = mcTBloadAll(int handle, const char* name,
mcOff start, mcOff ntables);mcTBload loads a relational table from a
database in memory, creating a structure of type
mcRTable. If a sub-table is selected, i.e
idiv > 0, only one sub-table can be loaded at
the time. If completed successfully, the function returns a pointer
to the table in memory. Otherwise, 0 is returned
and the error code can be retrieved by the function
mcerrstatus. To free the table from memory make
use of mcTBfree.
mcTBloadAll loads one or more relational
tables stored in sub-sets of a dataset from a database in memory,
creating an array of mcRTable relational tables.
The function works only for datasets containing sub-tables and
stored in a contiguous way. If completed successfully, the function
returns a pointer to the array of tables in memory. Otherwise, 0 is
returned and the error code can be retrieved by the function
mcErrStatus. To remove the array from memory,
make use of mcTBfreeAll for the whole
array, which will remove all elements of the array. Warning: The
elements mcRTable of this array returned by this
function must be referenced by
&x[i](x being the array
name and i the i-th element of that array) when
processing the sub-table by any of the mcTB
functions.
Both mcTBload and
mcTBloadAll also support reading rows of
sparse-table datasets. It is worth mentioning that using the sparse-table functions instead of
mcTBload and mcTBloadAll
for sub-tables will result in better performance.
handleDatabase handle (input).
nameName of relational table to be loaded in memory (input).
idivIndex of sub-table to be retrieved,
mcTBload only (input). If no sub-table
has been defined, i.e idiv=0 the
sub-table is ignored. If a sub-table has been defined,
idiv must be in the range of 1 to the
number of defined sub-tables.
For sparse-table datasets, idiv
must be positive and smaller or equal to the number of rows
of the dataset.
startStart index of sub-table to be retrieved (input),
mcTBloadAll only.
For sparse-table datasets, start
must be positive and smaller or equal to the number of rows
of the dataset.
ntablesNumber of sub-table to be retrieved (input),
mcTBloadAll only.