net.sf.jsqlparser.expression.Alias Java Examples

@Override
public void visit(Table table) {
    String tableName = table.getName();
    //关键点：解析到需要进行数据权限控制的表时进行拼装，可以从当前线程获取表数据
    //需要进行的数据权限控制的表数据
    Map<String, IdsAndColumn> tables = DPHelper.getLocalDataPermissions().getTables();
    if (tables.containsKey(tableName)) {
        IdsAndColumn idsAndColumn = tables.get(tableName);
        List<String> ids = idsAndColumn.getIds();
        List<String> columns = idsAndColumn.getColumns();

        SubSelect subSelect = new SubSelect();
        String subSql = SqlSpliceUtils.spliceIdAndColumn(tableName, ids, columns);
        try {
            subSelect.setSelectBody(((Select) (CCJSqlParserUtil.parse(subSql))).getSelectBody());
        } catch (JSQLParserException e) {
            logger.error("数据权限sql解析异常");
        }
        //TODO:采用随机别名不能避免重名
        subSelect.setAlias(table.getAlias() != null ? table.getAlias() : new Alias("DP" + UUID.randomUUID()
                .toString().replace("-", "")));
        this.subSelect = subSelect;
    }
}
 

private FromHolder generateFromHolder(FromHolder tholder, FromItem fromItem, List<Join> ljoin) throws ParseException, com.github.vincentrussell.query.mongodb.sql.converter.ParseException {
	Alias alias = fromItem.getAlias();
	tholder.addFrom(fromItem,(alias != null ? alias.getName() : null));
	
	if(ljoin != null) {
 	for (Join j : ljoin) {
 		SqlUtils.updateJoinType(j);
 		if(j.isInner() || j.isLeft()) {
 			tholder = generateFromHolder(tholder,j.getRightItem(),null);
 		}	
 		else{
 			throw new ParseException("Join type not suported");
 		}
 	}
	}
	return tholder;
}
 

private void parseFunctionForAggregation(Function function, Document document, List<String> groupBys, Alias alias) throws ParseException {
    String op = function.getName().toLowerCase();
    String aggField = SqlUtils.generateAggField(function, alias);
    switch(op) {
    	case "count":
    		document.put(aggField,new Document("$sum",1));
    		break;
    	case "sum":
    	case "min":
    	case "max":
    	case "avg":
    		createFunction(op,aggField, document,"$"+ SqlUtils.getFieldFromFunction(function));
    		break;
    	default:
    		throw new ParseException("could not understand function:" + function.getName());
    }
}
 

/**
 * 包装SetOperationList
 *
 * @param setOperationList
 * @return
 */
private SelectBody wrapSetOperationList(SetOperationList setOperationList) {
    //获取最后一个plainSelect
    PlainSelect plainSelect = setOperationList.getPlainSelects().get(setOperationList.getPlainSelects().size() - 1);

    PlainSelect selectBody = new PlainSelect();
    List<SelectItem> selectItems = getSelectItems(plainSelect);
    selectBody.setSelectItems(selectItems);

    //设置fromIterm
    SubSelect fromItem = new SubSelect();
    fromItem.setSelectBody(setOperationList);
    fromItem.setAlias(new Alias(WRAP_TABLE));
    selectBody.setFromItem(fromItem);
    //order by
    if (isNotEmptyList(plainSelect.getOrderByElements())) {
        selectBody.setOrderByElements(plainSelect.getOrderByElements());
        plainSelect.setOrderByElements(null);
    }
    return selectBody;
}
 

/**
 * 包装SetOperationList
 *
 * @param setOperationList
 * @return
 */
protected SelectBody wrapSetOperationList(SetOperationList setOperationList) {
    //获取最后一个plainSelect
    SelectBody setSelectBody = setOperationList.getSelects().get(setOperationList.getSelects().size() - 1);
    if (!(setSelectBody instanceof PlainSelect)) {
        throw new PageException("目前无法处理该SQL，您可以将该SQL发送给[email protected]协助作者解决!");
    }
    PlainSelect plainSelect = (PlainSelect) setSelectBody;
    PlainSelect selectBody = new PlainSelect();
    List<SelectItem> selectItems = getSelectItems(plainSelect);
    selectBody.setSelectItems(selectItems);

    //设置fromIterm
    SubSelect fromItem = new SubSelect();
    fromItem.setSelectBody(setOperationList);
    fromItem.setAlias(new Alias(WRAP_TABLE));
    selectBody.setFromItem(fromItem);
    //order by
    if (isNotEmptyList(plainSelect.getOrderByElements())) {
        selectBody.setOrderByElements(plainSelect.getOrderByElements());
        plainSelect.setOrderByElements(null);
    }
    return selectBody;
}
 

@Override
public String getColumnLabel(int column) throws SQLException {
  Alias alias = getAlias(column);
  if (alias != null)
    return alias.getName();
  return resultSet.getType().getStructFields().get(column - 1).getName();
}
 

private void registerColumn(Column column, Alias alias) {
  columns.add(column);
  aliases.add(alias);
}
 

private Alias getAlias(int column) throws SQLException {
  initMetaData();
  if (aliases == null || column > aliases.size())
    return null;
  return aliases.get(column - 1);
}
 

public static String generateAggField(Function f, Alias alias)  throws ParseException{
	String aliasStr = (alias == null? null : alias.getName());
	return generateAggField(f, aliasStr);
}