TableDerived.java
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package org.hsqldb;
import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.ParserDQL.CompileContext;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.OrderedHashMap;
import org.hsqldb.navigator.RowIterator;
import org.hsqldb.navigator.RowSetNavigatorData;
import org.hsqldb.navigator.RowSetNavigatorDataTable;
import org.hsqldb.persist.PersistentStore;
import org.hsqldb.result.Result;
import org.hsqldb.types.Type;
/**
 * Table with data derived from a query expression.
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.7.3
 * @since 1.9.0
 */
public class TableDerived extends Table {
    //
    public static final TableDerived[] emptyArray = new TableDerived[]{};
    //
    QueryExpression queryExpression;
    Expression      dataExpression;
    boolean         uniqueRows;
    boolean         uniquePredicate;
    String          sql;
    View            view;
    int             depth;
    boolean         canRecompile = false;
    public TableDerived(Database database, HsqlName name, int type) {
        super(database, name, type);
        switch (type) {
            // for special use, not INFORMATION_SCHEMA views
            case TableBase.CHANGE_SET_TABLE :
            case TableBase.SYSTEM_TABLE :
            case TableBase.MODULE_TABLE :
            case TableBase.FUNCTION_TABLE :
            case TableBase.VIEW_TABLE :
            case TableBase.RESULT_TABLE :
            case TableBase.SYSTEM_SUBQUERY :
                break;
            default :
                throw Error.runtimeError(ErrorCode.U_S0500, "Table");
        }
    }
    /**
     * For named sunbqueries.
     */
    public TableDerived(
            Database database,
            HsqlName name,
            int type,
            HsqlName[] colNames,
            Type[] colTypes) {
        this(database, name, type);
        // todo check column counts match
        for (int i = 0; i < colNames.length; i++) {
            ColumnSchema column = new ColumnSchema(colNames[i], colTypes[i]);
            columnList.add(column.getName().name, column);
        }
        columnCount = colNames.length;
        createPrimaryKey(null, null, false);
    }
    public TableDerived(
            Database database,
            HsqlName name,
            int type,
            Type[] columnTypes,
            OrderedHashMap<String, ColumnSchema> columnList,
            int[] pkColumns) {
        this(database, name, type);
        this.colTypes   = columnTypes;
        this.columnList = columnList;
        columnCount     = columnList.size();
        createPrimaryKey(null, pkColumns, true);
    }
    public TableDerived(
            Database database,
            HsqlName name,
            int type,
            QueryExpression queryExpression,
            Expression dataExpression,
            int opType,
            int depth) {
        super(database, name, type);
        switch (type) {
            case TableBase.SYSTEM_SUBQUERY :
            case TableBase.VIEW_TABLE :
                break;
            default :
                throw Error.runtimeError(ErrorCode.U_S0500, "Table");
        }
        this.queryExpression = queryExpression;
        this.dataExpression  = dataExpression;
        this.depth           = depth;
        switch (opType) {
            case OpTypes.EXISTS :
                queryExpression.setSingleRow();
                break;
            case OpTypes.IN :
                if (queryExpression != null) {
                    queryExpression.setFullOrder();
                }
                uniqueRows = true;
                break;
            case OpTypes.UNIQUE :
                queryExpression.setFullOrder();
                uniquePredicate = true;
                break;
            case OpTypes.MATCH_SIMPLE :
                queryExpression.setFullOrder();
                break;
            default :
        }
        if (dataExpression != null) {
            dataExpression.table = this;
        }
    }
    public TableDerived newDerivedTable(
            Session session,
            CompileContext baseContext) {
        TableDerived td = this;
        if (isRecompiled()) {
            ParserDQL p = new ParserDQL(session, new Scanner(), baseContext);
            p.compileContext.setCurrentSubquery(tableName);
            p.reset(session, sql);
            p.read();
            td = p.XreadSubqueryTableBody(tableName, OpTypes.TABLE_SUBQUERY);
            td.queryExpression.resolve(
                session,
                p.compileContext.getOuterRanges(),
                null);
            td.columnList   = columnList;
            td.columnCount  = columnList.size();
            td.triggerList  = triggerList;
            td.triggerLists = triggerLists;
            td.view         = view;
            td.createPrimaryKey();
        }
        return td;
    }
    public int getId() {
        return 0;
    }
    public boolean isQueryBased() {
        return true;
    }
    public boolean isWritable() {
        return true;
    }
    public boolean isInsertable() {
        if (view != null && view.isTriggerInsertable) {
            return false;
        }
        return queryExpression != null && queryExpression.isInsertable();
    }
    public boolean isUpdatable() {
        if (view != null && view.isTriggerUpdatable) {
            return false;
        }
        return queryExpression != null && queryExpression.isUpdatable();
    }
    public int[] getUpdatableColumns() {
        if (queryExpression != null) {
            return queryExpression.getBaseTableColumnMap();
        }
        return defaultColumnMap;
    }
    public boolean isTriggerInsertable() {
        if (view != null) {
            return view.isTriggerInsertable;
        }
        return false;
    }
    public boolean isTriggerUpdatable() {
        if (view != null) {
            return view.isTriggerUpdatable;
        }
        return false;
    }
    public boolean isTriggerDeletable() {
        if (view != null) {
            return view.isTriggerDeletable;
        }
        return false;
    }
    public Table getBaseTable() {
        return queryExpression == null
               ? this
               : queryExpression.getBaseTable();
    }
    public int[] getBaseTableColumnMap() {
        return queryExpression == null
               ? null
               : queryExpression.getBaseTableColumnMap();
    }
    public QueryExpression getQueryExpression() {
        return queryExpression;
    }
    public Expression getDataExpression() {
        return dataExpression;
    }
    public void prepareTable(Session session) {
        if (columnCount > 0) {
            return;
        }
        if (dataExpression != null) {
            if (columnCount == 0) {
                TableUtil.addAutoColumns(this, dataExpression.nodeDataTypes);
                setTableIndexesForSubquery(session);
            }
        }
        if (queryExpression != null) {
            columnList  = queryExpression.getColumns();
            columnCount = queryExpression.getColumnCount();
            setTableIndexesForSubquery(session);
        }
    }
    public void prepareTable(Session session, HsqlName[] columns) {
        prepareTable(session);
        if (columns != null) {
            if (columns.length != columnList.size()) {
                throw Error.error(ErrorCode.X_42593);
            }
            OrderedHashMap<String, ColumnSchema> newColumnList =
                new OrderedHashMap<>();
            for (int i = 0; i < columnCount; i++) {
                ColumnSchema col = columnList.get(i);
                col.setName(columns[i]);
                newColumnList.add(columns[i].name, col);
            }
            columnList = newColumnList;
        }
    }
    private void setTableIndexesForSubquery(Session session) {
        int[]   cols         = null;
        boolean hasFullIndex = false;
        if (queryExpression != null) {
            if (queryExpression.fullIndex != null) {
                hasFullIndex = true;
            }
        }
        if (hasFullIndex || uniqueRows || uniquePredicate) {
            cols = new int[getColumnCount()];
            ArrayUtil.fillSequence(cols);
        }
        int[] pkcols = uniqueRows
                       ? cols
                       : null;
        createPrimaryKey(null, pkcols, false);
        if (uniqueRows) {
            fullIndex = getPrimaryIndex();
        } else if (uniquePredicate || hasFullIndex) {
            fullIndex = createIndexForColumns(session, cols);
        }
    }
    void setCorrelated() {
        if (dataExpression != null) {
            dataExpression.isCorrelated = true;
        }
        if (queryExpression != null) {
            queryExpression.isCorrelated = true;
        }
    }
    boolean isCorrelated() {
        if (dataExpression != null) {
            return dataExpression.isCorrelated;
        }
        if (queryExpression != null) {
            return queryExpression.isCorrelated;
        }
        return false;
    }
    boolean hasUniqueNotNullRows(Session session) {
        return getNavigator(session).hasUniqueNotNullRows();
    }
    void resetToView() {
        queryExpression = view.getQueryExpression();
    }
    public void materialise(Session session) {
        session.sessionContext.pushStatementState();
        try {
            PersistentStore store;
            // table constructors
            if (dataExpression != null) {
                store = session.sessionData.getSubqueryRowStore(this);
                dataExpression.insertValuesIntoSubqueryTable(session, store);
                return;
            }
            if (queryExpression == null) {
                return;
            }
            Result result = queryExpression.getResult(session, 0);
            if (uniqueRows) {
                RowSetNavigatorData navigator =
                    ((RowSetNavigatorData) result.getNavigator());
                navigator.removeDuplicates();
            }
            store = session.sessionData.getSubqueryRowStore(this);
            insertResult(session, store, result);
            result.getNavigator().release();
        } finally {
            session.sessionContext.popStatementState();
        }
    }
    public void materialiseCorrelated(Session session) {
        if (isCorrelated()) {
            materialise(session);
        }
    }
    public boolean isRecompiled() {
        if (canRecompile && queryExpression instanceof QuerySpecification) {
            QuerySpecification qs = (QuerySpecification) queryExpression;
            return !qs.isAggregated && !qs.isGrouped && !qs.isOrderSensitive;
        }
        return false;
    }
    public Object[] getValues(Session session) {
        RowIterator it = rowIterator(session);
        if (it.next()) {
            Row row = it.getCurrentRow();
            if (it.next()) {
                throw Error.error(ErrorCode.X_21000);
            }
            return row.getData();
        } else {
            return new Object[getColumnCount()];
        }
    }
    public Object getValue(Session session) {
        Object[] data = getValues(session);
        return data[0];
    }
    public RowSetNavigatorData getNavigator(Session session) {
        RowSetNavigatorData navigator = new RowSetNavigatorDataTable(
            session,
            this);
        return navigator;
    }
    public void setSQL(String sql) {
        this.sql = sql;
    }
}