DB2ViewCache.java

/*
 * DBeaver - Universal Database Manager
 * Copyright (C) 2013-2016 Denis Forveille (titou10.titou10@gmail.com)
 * Copyright (C) 2010-2017 Serge Rider (serge@jkiss.org)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jkiss.dbeaver.ext.db2.model.cache;

import org.jkiss.code.NotNull;
import org.jkiss.code.Nullable;
import org.jkiss.dbeaver.DBException;
import org.jkiss.dbeaver.ext.db2.editors.DB2ObjectType;
import org.jkiss.dbeaver.ext.db2.model.DB2Schema;
import org.jkiss.dbeaver.ext.db2.model.DB2TableColumn;
import org.jkiss.dbeaver.ext.db2.model.DB2View;
import org.jkiss.dbeaver.ext.db2.model.dict.DB2TableType;
import org.jkiss.dbeaver.model.exec.jdbc.JDBCPreparedStatement;
import org.jkiss.dbeaver.model.exec.jdbc.JDBCResultSet;
import org.jkiss.dbeaver.model.exec.jdbc.JDBCSession;
import org.jkiss.dbeaver.model.exec.jdbc.JDBCStatement;
import org.jkiss.dbeaver.model.impl.jdbc.cache.JDBCStructLookupCache;

import java.sql.SQLException;

/**
 * Cache for DB2 Views
 * 
 * @author Denis Forveille
 */
public final class DB2ViewCache extends JDBCStructLookupCache<DB2Schema, DB2View, DB2TableColumn> {

    private static final String SQL_COLS_TAB = "SELECT * FROM SYSCAT.COLUMNS WHERE TABSCHEMA=? AND TABNAME = ? ORDER BY COLNO WITH UR";
    private static final String SQL_COLS_ALL = "SELECT * FROM SYSCAT.COLUMNS WHERE TABSCHEMA=? ORDER BY TABNAME, COLNO WITH UR";
    private static final String SQL_VIEW;
    private static final String SQL_VIEW_ALL;

    static {

        StringBuilder sb = new StringBuilder(256);
        sb.append("SELECT *");
        sb.append(" FROM SYSCAT.TABLES T");
        sb.append("    , SYSCAT.VIEWS V");
        sb.append(" WHERE V.VIEWSCHEMA = ?");
        sb.append("   AND T.TABSCHEMA = V.VIEWSCHEMA");
        sb.append("   AND T.TABNAME = V.VIEWNAME");
        sb.append("   AND T.TYPE IN ").append(DB2TableType.getInClause(DB2ObjectType.VIEW));
        sb.append(" ORDER BY T.TABNAME");
        sb.append(" WITH UR");
        SQL_VIEW_ALL = sb.toString();

        sb.setLength(0);

        sb.append("SELECT *");
        sb.append(" FROM SYSCAT.TABLES T");
        sb.append("    , SYSCAT.VIEWS V");
        sb.append(" WHERE V.VIEWSCHEMA = ?");
        sb.append("   AND V.VIEWNAME = ?");
        sb.append("   AND T.TABSCHEMA = V.VIEWSCHEMA");
        sb.append("   AND T.TABNAME = V.VIEWNAME");
        sb.append("   AND T.TYPE IN ").append(DB2TableType.getInClause(DB2ObjectType.VIEW));
        sb.append(" WITH UR");
        SQL_VIEW = sb.toString();
    }

    public DB2ViewCache()
    {
        super("TABNAME");
    }

    @NotNull
    @Override
    public JDBCStatement prepareLookupStatement(@NotNull JDBCSession session, @NotNull DB2Schema db2Schema,
        @Nullable DB2View db2View, @Nullable String db2ViewName) throws SQLException
    {
        if (db2View != null || db2ViewName != null) {
            final JDBCPreparedStatement dbStat = session.prepareStatement(SQL_VIEW);
            dbStat.setString(1, db2Schema.getName());
            dbStat.setString(2, db2View != null ? db2View.getName() : db2ViewName);
            return dbStat;
        } else {
            final JDBCPreparedStatement dbStat = session.prepareStatement(SQL_VIEW_ALL);
            dbStat.setString(1, db2Schema.getName());
            return dbStat;
        }
    }

    @Override
    protected DB2View fetchObject(@NotNull JDBCSession session, @NotNull DB2Schema db2Schema, @NotNull JDBCResultSet dbResult)
        throws SQLException, DBException
    {
        return new DB2View(session.getProgressMonitor(), db2Schema, dbResult);
    }

    @Override
    protected JDBCStatement prepareChildrenStatement(@NotNull JDBCSession session, @NotNull DB2Schema db2Schema,
        @Nullable DB2View forView) throws SQLException
    {

        String sql;
        if (forView != null) {
            sql = SQL_COLS_TAB;
        } else {
            sql = SQL_COLS_ALL;
        }
        JDBCPreparedStatement dbStat = session.prepareStatement(sql);
        dbStat.setString(1, db2Schema.getName());
        if (forView != null) {
            dbStat.setString(2, forView.getName());
        }
        return dbStat;
    }

    @Override
    protected DB2TableColumn fetchChild(@NotNull JDBCSession session, @NotNull DB2Schema db2Schema, @NotNull DB2View db2View,
        @NotNull JDBCResultSet dbResult) throws SQLException, DBException
    {
        return new DB2TableColumn(session.getProgressMonitor(), db2View, dbResult);
    }

}