Java ISelectable.setDistinct方法代码示例

import com.taobao.tddl.optimizer.core.expression.ISelectable; //导入方法依赖的package包/类
private void handleSelectOption(SelectOption option, List<ISelectable> selectItems) {
    if (option.resultDup == SelectDuplicationStrategy.DISTINCT) {
        for (ISelectable obj : selectItems) {
            obj.setDistinct(true);
        }
    }

    if (option.lockMode == LockMode.FOR_UPDATE) {
        tableNode.setLockMode(LOCK_MODE.EXCLUSIVE_LOCK);
    } else if (option.lockMode == LockMode.LOCK_IN_SHARE_MODE) {
        tableNode.setLockMode(LOCK_MODE.SHARED_LOCK);
    }
}
 

import com.taobao.tddl.optimizer.core.expression.ISelectable; //导入方法依赖的package包/类
public ISelectable buildSelectable(ISelectable c) {
    if (c == null) {
        return null;
    }

    ISelectable column = null;
    ISelectable columnFromMeta = null;

    if (column == null) {// 查找table meta
        columnFromMeta = this.getSelectableFromChild(c);

        if (columnFromMeta != null) {
            column = columnFromMeta;
            // 直接从子类的table定义中获取表字段，然后根据当前column状态，设置alias和distinct
            column.setAlias(c.getAlias());
            column.setDistinct(c.isDistinct());
        }
    }

    if (column instanceof IFunction) {

        buildFunction((IFunction) column);

    }

    return column;
}
 

import com.taobao.tddl.optimizer.core.expression.ISelectable; //导入方法依赖的package包/类
private void handleSelectOption(SelectOption option, List<ISelectable> selectItems) {
    if (option.resultDup == SelectDuplicationStrategy.DISTINCT) {
        for (ISelectable obj : selectItems) {
            obj.setDistinct(true);
        }
    }
}
 

import com.taobao.tddl.optimizer.core.expression.ISelectable; //导入方法依赖的package包/类
/**
 * 用于标记当前节点是否需要根据meta信息填充信息
 * 
 * <pre>
 * SQL. 
 *  a. select id + 2 as id , id from test where id = 2 having id = 4;
 *  b. select id + 2 as id , id from test where id = 2 order by count(id)
 * 
 * 解释：
 * 1.  COLUMN/WHERE/JOIN中列，是取自FROM的表字段
 * 2.  HAVING/ORDER BY/GROUP BY中的列，是取自SELECT中返回的字段，获取对应别名数据
 * </pre>
 * 
 * @param c
 * @param findInSelectList 如果在from的meta中找不到，是否继续在select中寻找
 * @return
 */
public ISelectable buildSelectable(ISelectable c, boolean findInSelectList) {
    if (c == null) {
        return null;
    }

    // 比如SELECT A.ID FROM TABLE1 A，将A.ID改名为TABLE1.ID
    if (c.getTableName() != null) {
        // 对于TableNode如果别名存在别名
        if (node instanceof TableNode && (!(node instanceof KVIndexNode))) {
            boolean isSameName = c.getTableName().equals(node.getAlias())
                                 || c.getTableName().equals(((TableNode) node).getTableName());
            if (node.isSubQuery() && node.getSubAlias() != null) {
                isSameName |= c.getTableName().equals(node.getSubAlias());
            }

            if (!isSameName) {
                throw new IllegalArgumentException("column: " + c.getFullName() + " is not existed in either "
                                                   + this.getNode().getName() + " or select clause");
            }
            c.setTableName(((TableNode) node).getTableName());// 统一改为表名
        }
    }

    ISelectable column = null;
    ISelectable columnFromMeta = null;

    if (findInSelectList) { // 优先查找select
        ISelectable columnFromSelected = getColumnFromSelecteList(c);
        if (columnFromSelected != null) {
            column = columnFromSelected;
            // 在select中找到了一次后，下次不能再从select中，遇到MAX(ID) AS ID会陷入死循环
            findInSelectList = false;
        }
    }

    if (column == null) {// 查找table meta
        columnFromMeta = this.getSelectableFromChild(c);
        if (columnFromMeta != null) {
            column = columnFromMeta;
            // 直接从子类的table定义中获取表字段，然后根据当前column状态，设置alias和distinct
            column.setAlias(c.getAlias());
            column.setDistinct(c.isDistinct());
        }
    }

    if (column == null) {
        throw new IllegalArgumentException("column: " + c.getFullName() + " is not existed in either "
                                           + this.getNode().getName() + " or select clause");
    }

    if ((column instanceof IColumn) && !IColumn.STAR.equals(column.getColumnName())) {
        node.addColumnsRefered(column); // refered不需要重复字段,select添加允许重复
        if (column.isDistinct()) {
            setExistAggregate();
        }
    }

    if (column instanceof IFunction) {
        buildFunction((IFunction) column, findInSelectList);
    }

    return column;
}