Java Select类代码示例

import org.h2.command.dml.Select; //导入依赖的package包/类
@Override
public void updateAggregate(Session session) {
    Value now = columnResolver.getValue(column);
    Select select = columnResolver.getSelect();
    if (select == null) {
        throw DbException.get(ErrorCode.MUST_GROUP_BY_COLUMN_1, getSQL());
    }
    HashMap<Expression, Object> values = select.getCurrentGroup();
    if (values == null) {
        // this is a different level (the enclosing query)
        return;
    }
    Value v = (Value) values.get(this);
    if (v == null) {
        values.put(this, now);
    } else {
        if (!database.areEqual(now, v)) {
            throw DbException.get(ErrorCode.MUST_GROUP_BY_COLUMN_1, getSQL());
        }
    }
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
@Override
public Value getValue(Session session) {
    Select select = columnResolver.getSelect();
    if (select != null) {
        HashMap<Expression, Object> values = select.getCurrentGroup();
        if (values != null) {
            Value v = (Value) values.get(this);
            if (v != null) {
                return v;
            }
        }
    }
    Value value = columnResolver.getValue(column);
    if (value == null) {
        columnResolver.getValue(column);
        throw DbException.get(ErrorCode.MUST_GROUP_BY_COLUMN_1, getSQL());
    }
    return value;
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
private DataField[] getFields(Select select, DataField[] fields) {
	ArrayList<DataField> toReturn = new ArrayList<DataField>();
	try {
		for (int i=0;i<select.getColumnCount();i++) {
			String name = select.queryMeta().getColumnName(i);
			if (name.equalsIgnoreCase("timed") || name.equalsIgnoreCase("pk") )
				continue;
			String gsnType = null;
			for (int j=0;j<fields.length;j++) {
				if (fields[j].getName().equalsIgnoreCase(name)) {	
					gsnType=fields[j].getType();
					toReturn.add( new DataField(name,gsnType));
					break;
				}
			}				
		}
		return toReturn.toArray(new DataField[] {});
	}catch (Exception e) {
		logger.debug(e.getMessage(),e);
		return new DataField[0];
	}
	
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
/**
 * Create a new table filter object.
 *
 * @param session the session
 * @param table the table from where to read data
 * @param alias the alias name
 * @param rightsChecked true if rights are already checked
 * @param select the select statement
 */
public TableFilter(Session session, Table table, String alias,
        boolean rightsChecked, Select select) {
    this.session = session;
    this.table = table;
    this.alias = alias;
    this.select = select;
    this.cursor = new IndexCursor(this);
    if (!rightsChecked) {
        session.getUser().checkRight(table, Right.SELECT);
    }
    hashCode = session.nextObjectId();
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
private Query parseSelectSub() {
    if (readIf("(")) {
        Query command = parseSelectUnion();
        read(")");
        return command;
    }
    Select select = parseSelectSimple();
    return select;
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
private void parseJoinTableFilter(TableFilter top, final Select command) {
    top = readJoin(top, command, false, top.isJoinOuter());
    command.addTableFilter(top, true);
    boolean isOuter = false;
    while (true) {
        TableFilter n = top.getNestedJoin();
        if (n != null) {
            n.visit(new TableFilterVisitor() {
                @Override
                public void accept(TableFilter f) {
                    command.addTableFilter(f, false);
                }
            });
        }
        TableFilter join = top.getJoin();
        if (join == null) {
            break;
        }
        isOuter = isOuter | join.isJoinOuter();
        if (isOuter) {
            command.addTableFilter(join, false);
        } else {
            // make flat so the optimizer can work better
            Expression on = join.getJoinCondition();
            if (on != null) {
                command.addCondition(on);
            }
            join.removeJoinCondition();
            top.removeJoin();
            command.addTableFilter(join, true);
        }
        top = join;
    }
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
private Select parseValues() {
    Select command = new Select(session);
    currentSelect = command;
    TableFilter filter = parseValuesTable();
    ArrayList<Expression> list = New.arrayList();
    list.add(new Wildcard(null, null));
    command.setExpressions(list);
    command.addTableFilter(filter, true);
    command.init();
    return command;
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
/**
 * @param qry Query.
 * @return Parsed query AST.
 */
private GridSqlQuery parseQuery(Query qry) {
    if (qry instanceof Select)
        return parseSelect((Select)qry);

    if (qry instanceof SelectUnion)
        return parseUnion((SelectUnion)qry);

    throw new UnsupportedOperationException("Unknown query type: " + qry);
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
/**
 * @param qry Query.
 */
private void collectOptimizedTableFiltersOrder(Query qry) {
    if (qry instanceof SelectUnion) {
        collectOptimizedTableFiltersOrder(((SelectUnion)qry).getLeft());
        collectOptimizedTableFiltersOrder(((SelectUnion)qry).getRight());
    }
    else {
        Select select = (Select)qry;

        TableFilter filter = select.getTopTableFilter();

        int i = 0;

        do {
            assert0(filter != null, select);
            assert0(filter.getNestedJoin() == null, select);

            // Here all the table filters must have generated unique aliases,
            // thus we can store them in the same map for all the subqueries.
            optimizedTableFilterOrder.put(filter.getTableAlias(), i++);

            Table tbl = filter.getTable();

            // Go down and collect inside of optimized subqueries.
            if (tbl instanceof TableView) {
                ViewIndex viewIdx = (ViewIndex)filter.getIndex();

                collectOptimizedTableFiltersOrder(viewIdx.getQuery());
            }

            filter = filter.getJoin();
        }
        while (filter != null);
    }
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
/**
 * Returns null if the validation fails. Returns the table name used in the query if the validation succeeds.
 * @param query to validate.
 * @return Null if the validation fails. The name of the table if the validation succeeds.
 */
public  String validateQuery(String query) {
	Select select = queryToSelect(query);
	if (select ==null)
		return null;
	if ((select.getTables().size() != 1) || (select.getTopFilters().size()!=1) || select.isQuickAggregateQuery() ) 
		return null;
	return select.getTables().iterator().next().getName();
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
public  DataField[] extractSelectColumns(String query, VSensorConfig vSensorConfig) {
	Select select = queryToSelect(query);
	if (select ==null)
		return new DataField[0];
	
	return getFields(select,vSensorConfig.getOutputStructure());
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
public static String addPkField(String query) {
     logger.debug("< QUERY IN: " + query);
     try {
         SQLValidator sv = getInstance();
         Select select = sv.queryToSelect(query);
         if (select == null)
             return query;
         boolean hasPk = false;
         boolean hasWildCard = false;
         for (int i=0;i<select.getColumnCount();i++) {
	String name = select.queryMeta().getColumnName(i);
	if (name.equalsIgnoreCase("*")) {
                 hasWildCard = true;
                 break;
             }
             if (name.equalsIgnoreCase("pk")) {
                 hasPk = true;
                 break;
             }
}
         //
         if (! hasPk && !hasWildCard) {
             int is = query.toUpperCase().indexOf("SELECT");
             query = new StringBuilder(query.substring(is,is+6))
                     .append(" pk, ")
                     .append(query.substring(is+7)).toString();
         }
     }
     catch (Exception e) {
         logger.error(e.getMessage(), e);    
     }
     logger.debug("> QUERY OUT: " + query);
     return query;
 }
 

import org.h2.command.dml.Select; //导入依赖的package包/类
public JavaAggregate(UserAggregate userAggregate, Expression[] args,
        Select select) {
    this.userAggregate = userAggregate;
    this.args = args;
    this.select = select;
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
@Override
public Select getSelect() {
    return null;
}
 

import org.h2.command.dml.Select; //导入依赖的package包/类
@Override
public Select getSelect() {
    return select;
}