Gets a string chunk from the column.
public virtual size_t GetStringChunk( const char * cname, char * dst, size_t len, size_t offset )
cname The name of the column.
dst The buffer to hold the string chunk. The string is null-terminated even if truncated.
len The size of the buffer in bytes.
offset The offset into the value at which to start reading or UL_BLOB_CONTINUE to continue from where the last read ended.
The number of bytes copied to the destination buffer excluding the null-terminator. If dst is NULL, the number of bytes left in the string is returned.
The end of the value has been reached if 0 is returned.