Examples with Command org.h2.command.Command used on opensource projects

Example 21 with Command

use of org.h2.command.Command in project h2database by h2database.

the class Parser method parseSelectSimpleFromPart.

private void parseSelectSimpleFromPart(Select command) {
    do {
        TableFilter filter = readTableFilter();
        parseJoinTableFilter(filter, command);
    } while (readIf(","));
    // to get the order as it was in the original query.
    if (session.isForceJoinOrder()) {
        sortTableFilters(command.getTopFilters());
    }
}

Example 22 with Command

use of org.h2.command.Command in project h2database by h2database.

the class Parser method parseRollback.

private TransactionCommand parseRollback() {
    TransactionCommand command;
    if (readIf("TRANSACTION")) {
        command = new TransactionCommand(session, CommandInterface.ROLLBACK_TRANSACTION);
        command.setTransactionName(readUniqueIdentifier());
        return command;
    }
    if (readIf("TO")) {
        read("SAVEPOINT");
        command = new TransactionCommand(session, CommandInterface.ROLLBACK_TO_SAVEPOINT);
        command.setSavepointName(readUniqueIdentifier());
    } else {
        readIf("WORK");
        command = new TransactionCommand(session, CommandInterface.ROLLBACK);
    }
    return command;
}

Example 23 with Command

use of org.h2.command.Command in project h2database by h2database.

the class Parser method parseMergeUsing.

private MergeUsing parseMergeUsing(Merge oldCommand, int start) {
    MergeUsing command = new MergeUsing(oldCommand);
    currentPrepared = command;
    if (readIf("(")) {
        /* a select query is supplied */
        if (isSelect()) {
            command.setQuery(parseSelect());
            read(")");
        }
        command.setQueryAlias(readFromAlias(null, Collections.singletonList("ON")));
        String[] querySQLOutput = { null };
        List<Column> columnTemplateList = TableView.createQueryColumnTemplateList(null, command.getQuery(), querySQLOutput);
        TableView temporarySourceTableView = createCTEView(command.getQueryAlias(), querySQLOutput[0], columnTemplateList, false, /* no recursion */
        false, /* do not add to session */
        false, /* isPersistent */
        session);
        TableFilter sourceTableFilter = new TableFilter(session, temporarySourceTableView, command.getQueryAlias(), rightsChecked, (Select) command.getQuery(), 0, null);
        command.setSourceTableFilter(sourceTableFilter);
    } else {
        /* Its a table name, simulate a query by building a select query for the table */
        List<String> excludeIdentifiers = Collections.singletonList("ON");
        TableFilter sourceTableFilter = readSimpleTableFilter(0, excludeIdentifiers);
        command.setSourceTableFilter(sourceTableFilter);
        StringBuilder buff = new StringBuilder("SELECT * FROM ");
        appendTableWithSchemaAndAlias(buff, sourceTableFilter.getTable(), sourceTableFilter.getTableAlias());
        Prepared preparedQuery = prepare(session, buff.toString(), null);
        command.setQuery((Select) preparedQuery);
    }
    read("ON");
    read("(");
    Expression condition = readExpression();
    command.setOnCondition(condition);
    read(")");
    if (readIfAll("WHEN", "MATCHED", "THEN")) {
        int startMatched = lastParseIndex;
        if (readIf("UPDATE")) {
            Update updateCommand = new Update(session);
            // currentPrepared = updateCommand;
            TableFilter filter = command.getTargetTableFilter();
            updateCommand.setTableFilter(filter);
            parseUpdateSetClause(updateCommand, filter, startMatched);
            command.setUpdateCommand(updateCommand);
        }
        startMatched = lastParseIndex;
        if (readIf("DELETE")) {
            Delete deleteCommand = new Delete(session);
            TableFilter filter = command.getTargetTableFilter();
            deleteCommand.setTableFilter(filter);
            parseDeleteGivenTable(deleteCommand, null, startMatched);
            command.setDeleteCommand(deleteCommand);
        }
    }
    if (readIfAll("WHEN", "NOT", "MATCHED", "THEN")) {
        if (readIf("INSERT")) {
            Insert insertCommand = new Insert(session);
            insertCommand.setTable(command.getTargetTable());
            parseInsertGivenTable(insertCommand, command.getTargetTable());
            command.setInsertCommand(insertCommand);
        }
    }
    setSQL(command, "MERGE", start);
    // build and prepare the targetMatchQuery ready to test each rows
    // existence in the target table (using source row to match)
    StringBuilder targetMatchQuerySQL = new StringBuilder("SELECT _ROWID_ FROM ");
    appendTableWithSchemaAndAlias(targetMatchQuerySQL, command.getTargetTable(), command.getTargetTableFilter().getTableAlias());
    targetMatchQuerySQL.append(" WHERE ").append(command.getOnCondition().getSQL());
    command.setTargetMatchQuery((Select) parse(targetMatchQuerySQL.toString()));
    return command;
}

Example 24 with Command

use of org.h2.command.Command in project h2database by h2database.

the class Parser method parseEndOfQuery.

private void parseEndOfQuery(Query command) {
    if (readIf("ORDER")) {
        read("BY");
        Select oldSelect = currentSelect;
        if (command instanceof Select) {
            currentSelect = (Select) command;
        }
        ArrayList<SelectOrderBy> orderList = New.arrayList();
        do {
            boolean canBeNumber = true;
            if (readIf("=")) {
                canBeNumber = false;
            }
            SelectOrderBy order = new SelectOrderBy();
            Expression expr = readExpression();
            if (canBeNumber && expr instanceof ValueExpression && expr.getType() == Value.INT) {
                order.columnIndexExpr = expr;
            } else if (expr instanceof Parameter) {
                recompileAlways = true;
                order.columnIndexExpr = expr;
            } else {
                order.expression = expr;
            }
            if (readIf("DESC")) {
                order.descending = true;
            } else {
                readIf("ASC");
            }
            if (readIf("NULLS")) {
                if (readIf("FIRST")) {
                    order.nullsFirst = true;
                } else {
                    read("LAST");
                    order.nullsLast = true;
                }
            }
            orderList.add(order);
        } while (readIf(","));
        command.setOrder(orderList);
        currentSelect = oldSelect;
    }
    // make sure aggregate functions will not work here
    Select temp = currentSelect;
    currentSelect = null;
    // http://sqlpro.developpez.com/SQL2008/
    if (readIf("OFFSET")) {
        command.setOffset(readExpression().optimize(session));
        if (!readIf("ROW")) {
            readIf("ROWS");
        }
    }
    if (readIf("FETCH")) {
        if (!readIf("FIRST")) {
            read("NEXT");
        }
        if (readIf("ROW")) {
            command.setLimit(ValueExpression.get(ValueInt.get(1)));
        } else {
            Expression limit = readExpression().optimize(session);
            command.setLimit(limit);
            if (!readIf("ROW")) {
                read("ROWS");
            }
        }
        read("ONLY");
    }
    currentSelect = temp;
    if (readIf("LIMIT")) {
        temp = currentSelect;
        // make sure aggregate functions will not work here
        currentSelect = null;
        Expression limit = readExpression().optimize(session);
        command.setLimit(limit);
        if (readIf("OFFSET")) {
            Expression offset = readExpression().optimize(session);
            command.setOffset(offset);
        } else if (readIf(",")) {
            // MySQL: [offset, ] rowcount
            Expression offset = limit;
            limit = readExpression().optimize(session);
            command.setOffset(offset);
            command.setLimit(limit);
        }
        if (readIf("SAMPLE_SIZE")) {
            Expression sampleSize = readExpression().optimize(session);
            command.setSampleSize(sampleSize);
        }
        currentSelect = temp;
    }
    if (readIf("FOR")) {
        if (readIf("UPDATE")) {
            if (readIf("OF")) {
                do {
                    readIdentifierWithSchema();
                } while (readIf(","));
            } else if (readIf("NOWAIT")) {
            // TODO parser: select for update nowait: should not wait
            }
            command.setForUpdate(true);
        } else if (readIf("READ") || readIf("FETCH")) {
            read("ONLY");
        }
    }
    if (database.getMode().isolationLevelInSelectOrInsertStatement) {
        parseIsolationClause();
    }
}

Example 25 with Command

use of org.h2.command.Command in project h2database by h2database.

the class Parser method parseAlterIndex.

private AlterIndexRename parseAlterIndex() {
    boolean ifExists = readIfExists(false);
    String indexName = readIdentifierWithSchema();
    Schema old = getSchema();
    AlterIndexRename command = new AlterIndexRename(session);
    command.setOldSchema(old);
    command.setOldName(indexName);
    command.setIfExists(ifExists);
    read("RENAME");
    read("TO");
    String newName = readIdentifierWithSchema(old.getName());
    checkSchema(old);
    command.setNewName(newName);
    return command;
}