/*
* This is free software, licensed under the Gnu Public License (GPL) get a copy from <http://www.gnu.org/licenses/gpl.html>
*
* author: Henner Zeller <H.Zeller@acm.org>
*/
package henplus.commands;
import henplus.AbstractCommand;
import henplus.CommandDispatcher;
import henplus.HenPlus;
import henplus.Interruptable;
import henplus.SQLSession;
import henplus.SigIntHandler;
import henplus.logging.Logger;
import henplus.view.Column;
import henplus.view.ColumnMetaData;
import henplus.view.TableRenderer;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.StringTokenizer;
/**
* document me.
*/
public class DescribeCommand extends AbstractCommand implements Interruptable {
private static final String[] LIST_TABLES = { "TABLE", "VIEW" };
private static final ColumnMetaData[] DESC_META;
static {
DESC_META = new ColumnMetaData[9];
DESC_META[0] = new ColumnMetaData("#", ColumnMetaData.ALIGN_RIGHT);
DESC_META[1] = new ColumnMetaData("table");
DESC_META[2] = new ColumnMetaData("column");
DESC_META[3] = new ColumnMetaData("type");
DESC_META[4] = new ColumnMetaData("null");
DESC_META[5] = new ColumnMetaData("default");
DESC_META[6] = new ColumnMetaData("pk");
DESC_META[7] = new ColumnMetaData("fk");
DESC_META[8] = new ColumnMetaData("remark", ColumnMetaData.ALIGN_LEFT, 60);
}
private volatile boolean _interrupted;
private final ListUserObjectsCommand _tableCompleter;
public DescribeCommand(final ListUserObjectsCommand tc) {
_tableCompleter = tc;
}
/**
* returns the command-strings this command can handle.
*/
@Override
public String[] getCommandList() {
return new String[] { "describe", "idescribe" };
}
/**
* execute the command given.
*/
@Override
public int execute(final SQLSession session, final String cmd, final String param) {
// make use of properties for these properties?
// (since the options just toggle, this may be convenient)
boolean showDescriptions = true;
boolean showIndex = "idescribe".equals(cmd);
boolean showTime = true;
final StringTokenizer st = new StringTokenizer(param);
if (st.countTokens() < 1) {
return SYNTAX_ERROR;
}
// this was a flag to ensure that all options come before the tablenames
// can probably be removed...
final boolean moreOptions = true;
while (st.hasMoreTokens()) {
String tabName = st.nextToken();
if (moreOptions && tabName.startsWith("-")) {
if (tabName.indexOf('i') > -1) {
showIndex = !showIndex;
}
if (tabName.indexOf('v') > -1) {
showDescriptions = !showDescriptions;
}
if (tabName.indexOf('t') > -1) {
showTime = !showTime;
}
} else {
// more_options = false; // options can stand at every position
// --> toggle
boolean correctName = true;
if (tabName.startsWith("\"")) {
tabName = stripQuotes(tabName);
correctName = false;
}
// separate schama and table.
String schema = null;
final int schemaDelim = tabName.indexOf('.');
if (schemaDelim > 0) {
schema = tabName.substring(0, schemaDelim);
tabName = tabName.substring(schemaDelim + 1);
}
// FIXME: provide correct name as well for schema!
if (correctName) {
final String alternative = _tableCompleter.correctTableName(tabName);
if (alternative != null && !alternative.equals(tabName)) {
tabName = alternative;
HenPlus.out().println("describing table: '" + tabName + "' (corrected name)");
}
}
ResultSet rset = null;
final Set<String> doubleCheck = new HashSet<String>();
try {
_interrupted = false;
SigIntHandler.getInstance().pushInterruptable(this);
boolean anyLeftArrow = false;
boolean anyRightArrow = false;
final long startTime = System.currentTimeMillis();
final String catalog = session.getConnection().getCatalog();
String description = null;
String tableType = null;
if (_interrupted) {
return SUCCESS;
}
final DatabaseMetaData meta = session.getConnection().getMetaData();
for (int i = 0; i < DESC_META.length; ++i) {
DESC_META[i].resetWidth();
}
rset = meta.getTables(catalog, schema, tabName, LIST_TABLES);
if (rset != null && rset.next()) {
tableType = rset.getString(4);
description = rset.getString(5); // remark
}
rset.close();
/*
* get primary keys.
*/
if (_interrupted) {
return SUCCESS;
}
final Map<String, String> pks = new HashMap<String, String>();
rset = meta.getPrimaryKeys(null, schema, tabName);
if (rset != null) {
while (!_interrupted && rset.next()) {
final String col = rset.getString(4);
final int pkseq = rset.getInt(5);
final String pkname = rset.getString(6);
String desc = pkname != null ? pkname : "*";
if (pkseq > 1) {
desc = new StringBuilder().append(desc).append("{").append(pkseq).append("}").toString();
}
pks.put(col, desc);
}
rset.close();
}
/*
* get referenced primary keys.
*/
if (_interrupted) {
return SUCCESS;
}
rset = meta.getExportedKeys(null, schema, tabName);
if (rset != null) {
while (!_interrupted && rset.next()) {
final String col = rset.getString(4);
String fktable = rset.getString(7);
final String fkcolumn = rset.getString(8);
fktable = new StringBuilder().append(fktable).append("(").append(fkcolumn).append(")").toString();
String desc = pks.get(col);
desc = desc == null ? new StringBuilder().append(" <- ").append(fktable).toString()
: new StringBuilder().append(desc).append("\n <- ").append(fktable).toString();
anyLeftArrow = true;
pks.put(col, desc);
}
rset.close();
}
/*
* get foreign keys.
*/
if (_interrupted) {
return SUCCESS;
}
final Map<String, String> fks = new HashMap<String, String>();
// some jdbc version 2 drivers (connector/j) have problems
// with foreign keys...
try {
rset = meta.getImportedKeys(null, schema, tabName);
} catch (final NoSuchElementException e) {
Logger.debug("Database problem reading meta data: ", e);
}
if (rset != null) {
while (!_interrupted && rset.next()) {
String table = rset.getString(3);
final String pkcolumn = rset.getString(4);
table = table + "(" + pkcolumn + ")";
final String col = rset.getString(8);
final String fkname = rset.getString(12);
String desc = fkname != null ? new StringBuilder().append(fkname).append("\n -> ").toString() : " -> ";
desc += table;
anyRightArrow = true;
fks.put(col, desc);
}
rset.close();
}
HenPlus.out().println(("VIEW".equals(tableType) ? "View: " : "Table: ") + tabName);
if (description != null) {
HenPlus.out().println(description);
}
if (catalog != null) {
HenPlus.msg().println("catalog: " + catalog);
}
if (anyLeftArrow) {
HenPlus.msg().println(" '<-' : referenced by");
}
if (anyRightArrow) {
HenPlus.msg().println(" '->' : referencing");
}
/*
* if all columns belong to the same table name, then don't
* report it. A different table name may only occur in rare
* circumstance like object oriented databases.
*/
boolean allSameTableName = true;
/*
* build up actual describe table.
*/
if (_interrupted) {
return SUCCESS;
}
rset = meta.getColumns(catalog, schema, tabName, null);
final List<Column[]> rows = new ArrayList<Column[]>();
int colNum = 0;
boolean anyDescription = false;
if (rset != null) {
while (!_interrupted && rset.next()) {
final Column[] row = new Column[9];
row[0] = new Column(++colNum);
final String thisTabName = rset.getString(3);
row[1] = new Column(thisTabName);
allSameTableName &= tabName.equals(thisTabName);
final String colname = rset.getString(4);
if (doubleCheck.contains(colname)) {
continue;
}
doubleCheck.add(colname);
row[2] = new Column(colname);
String type = rset.getString(6);
final int colSize = rset.getInt(7);
final int colDp = rset.getInt(9);
if (colSize > 0) {
if (colDp == 0) {
type = type + "(" + colSize +")";
} else {
type = type + "(" + colSize + "," + colDp + ")";
}
}
row[3] = new Column(type);
final String defaultVal = rset.getString(13);
row[4] = new Column(rset.getString(18));
// oracle appends newline to default values for some
// reason.
row[5] = new Column((defaultVal != null ? defaultVal.trim() : null));
final String pkdesc = pks.get(colname);
row[6] = new Column(pkdesc != null ? pkdesc : "");
final String fkdesc = fks.get(colname);
row[7] = new Column(fkdesc != null ? fkdesc : "");
final String colDesc = showDescriptions ? rset.getString(12) : null;
row[8] = new Column(colDesc);
anyDescription |= colDesc != null;
rows.add(row);
}
}
rset.close();
/*
* we render the table now, since we only know now, whether
* we will show the first column and the description column
* or not.
*/
DESC_META[1].setDisplay(!allSameTableName);
DESC_META[8].setDisplay(anyDescription);
final TableRenderer table = new TableRenderer(DESC_META, HenPlus.out());
final Iterator<Column[]> it = rows.iterator();
while (it.hasNext()) {
table.addRow(it.next());
}
table.closeTable();
if (_interrupted) {
return SUCCESS;
}
if (showIndex) {
showIndexInformation(tabName, schema, meta);
}
if (showTime) {
TimeRenderer.printTime(System.currentTimeMillis() - startTime, HenPlus.out());
HenPlus.out().println();
}
} catch (final Exception e) {
final String ex = e.getMessage() != null ? e.getMessage().trim() : e.toString();
Logger.error("Database problem reading meta data: ", ex);
return EXEC_FAILED;
} finally {
if (rset != null) {
try {
rset.close();
} catch (final Exception e) {
}
}
}
}
}
return SUCCESS;
}
/**
* @param tabName
* @param schema
* @param meta
* @return @throws SQLException
*/
private void showIndexInformation(final String tabName, final String schema, final DatabaseMetaData meta) throws SQLException {
ResultSet rset;
HenPlus.out().println("index information:");
boolean anyIndex = false;
rset = meta.getIndexInfo(null, schema, tabName, false, true);
if (rset != null) {
while (!_interrupted && rset.next()) {
boolean nonUnique;
String idxName = null;
nonUnique = rset.getBoolean(4);
idxName = rset.getString(6);
if (idxName == null) {
continue; // statistics, otherwise.
}
// output part.
anyIndex = true;
HenPlus.out().print("\t");
if (!nonUnique) {
HenPlus.out().print("unique ");
}
HenPlus.out().print("index " + idxName);
final String colName = rset.getString(9);
// work around postgres-JDBC-driver bug:
if (colName != null && colName.length() > 0) {
HenPlus.out().print(" on " + colName);
}
HenPlus.out().println();
}
}
rset.close();
if (!anyIndex) {
HenPlus.out().println("\t<none>");
}
}
/**
* complete the table name.
*/
@Override
public Iterator<String> complete(final CommandDispatcher disp, final String partialCommand, String lastWord) {
final StringTokenizer st = new StringTokenizer(partialCommand);
st.nextElement(); // consume first element.
if (lastWord.startsWith("\"")) {
lastWord = lastWord.substring(1);
}
return _tableCompleter.completeTableName(HenPlus.getInstance().getCurrentSession(), lastWord);
}
private String stripQuotes(String value) {
if (value.startsWith("\"") && value.endsWith("\"")) {
value = value.substring(1, value.length() - 1);
}
return value;
}
// -- Interruptable interface
@Override
public synchronized void interrupt() {
_interrupted = true;
}
/**
* return a descriptive string.
*/
@Override
public String getShortDescription() {
return "describe a database object";
}
@Override
public String getSynopsis(final String cmd) {
return cmd + " [options] <tablenames>";
}
@Override
public String getLongDescription(final String cmd) {
String dsc;
dsc = "\tDescribe the meta information of the named user object\n"
+ "\t(only tables for now). The name you type is case sensitive\n"
+ "\tbut henplus tries its best to correct it.\n" + "\tThe 'describe' command just describes the table, the\n"
+ "\t'idescribe' command determines the index information as\n"
+ "\twell; some databases are really slow in this, so this is\n" + "\tan extra command\n\n"
// include the command line options:
+ super.getLongDescription(cmd)
+ "\n\tIf an option is positioned between two tablenames, its current state is toggled." + "\n";
return dsc;
}
}
/*
* Emacs: Local variables: c-basic-offset: 4 tab-width: 8 indent-tabs-mode: nil
* compile-command: "ant -emacs -find build.xml" End: vi:set tabstop=8
* shiftwidth=4 nowrap:
*/