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String henplus::commands::DumpCommand::getLongDescription ( String  cmd  )  [inline]

returns a longer string describing this action. This should return a String describing details of the given command. This String should start with a TAB-character in each new line (the first line is a new line). The last line should not end with newline.

cmd The command the long description is asked for. This is one of the possible commands returned by getCommandList().

Reimplemented from henplus::AbstractCommand.

Definition at line 1217 of file DumpCommand.java.

      String dsc = null;
      if ("dump-out".equals(cmd)) {
          dsc= "\tDump out the contents of the table(s) given to the file\n"
            +"\twith the given name. If the filename ends with '.gz', the\n"
            +"\tcontent is gzip'ed automatically .. that saves space.\n\n"
            +"\tThe dump-format allows to read in the data back into\n"
            +"\tthe database ('dump-in' command). And unlike pure SQL-insert\n"
            +"\tstatements, this works even across databases.\n"
            +"\tSo you can make a dump of your MySQL database and read it\n"
            +"\tback into Oracle, for instance. To achive this database\n"
            +"\tindependence, the data is stored in a canonical form\n"
            +"\t(e.g. the Time/Date). The file itself is human readable\n"
            +"\tand uses less space than simple SQL-inserts:\n"
            +"\t  (tabledump 'student'\n"
            +"\t    (dump-version 1 1)\n"
            +"\t    (henplus-version 0.3.3)\n"
            +"\t    (database-info 'MySQL - 3.23.47')\n"
            +"\t    (meta ('name',   'sex',    'student_id')\n"
            +"\t          ('STRING', 'STRING', 'INTEGER'   ))\n"
            +"\t    (data ('Megan','F',1)\n"
            +"\t          ('Joseph','M',2)\n"
            +"\t          ('Kyle','M',3)\n"
            +"\t          ('Mac Donald\\'s','M',4))\n"
            +"\t    (rows 4))\n"
            +"\tThis format contains only the data, no\n"
            +"\tcanonical 'create table' statement - so the table must\n"
            +"\talready exist at import time. Both these features will\n"
            +"\tbe in later versions of HenPlus.";

      else if ("dump-conditional".equals(cmd)) {
          dsc= "\tLike dump-out, but dump only the rows of a single table\n"
            +"\tthat match the where clause.";
      else if ("dump-in".equals(cmd)) {
          dsc= "\tRead back in the data that has been dumped out with the\n"
            +"\t'dump-out' command. If the filename ends with '.gz',\n"
            +"\tthen the content is assumed to be gzipped and is\n"
            +"\tunpacked on the fly. The 'dump-in' command fills\n"
            +"\texisting tables, it does not create missing ones!\n\n"
                +"\tExisting content ist not deleted before, dump-in just\n"
                +"\tinserts all data found in the dump.\n\n"
            +"\tInternally, the import uses a prepared statement that is\n"
            +"\tfed with the typed data according to the meta data (see\n"
            +"\tdump-out for the file format). This evens out differences\n"
            +"\tbetween databases and of course enhances speed compared\n"
            +"\tto non-prepared statements.\n\n"
            +"\tThe import is done in the current transaction, unless\n"
            +"\tyou specify the commitpoints. The commitpoints specify\n"
            +"\tthe number of inserts, that are executed before an commit\n"
            +"\tis done. For a large amount of data this option is\n"
            +"\tnecessary, since otherwise your rollback-segments\n"
            +"\tmight get a problem ;-)";

      else if ("verify-dump".equals(cmd)) {
          dsc= "\tLike dump-in, but a 'dry run'. Won't change anything\n"
            +"\tbut parses the whole file to determine whether it has\n"
            +"\tsyntax errors or is damaged. Any syntax errors are\n"
            +"\treported as it were a 'dump-in'. Problems that might\n"
            +"\toccur in a 'real' import in the database (that might\n"
            +"\tdetect, that the import would create duplicate keys for\n"
            +"\tinstance) can not be determined, of course.";
      return dsc;

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