content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  
  package com.actiontech.dble.plan.common.item.subquery;
  
  import com.actiontech.dble.config.ErrorCode;
  import com.actiontech.dble.meta.ProxyMetaManager;
  import com.actiontech.dble.plan.common.exception.MySQLOutPutException;
  import com.actiontech.dble.plan.common.field.Field;
  import com.actiontech.dble.plan.common.item.Item;
  import com.actiontech.dble.plan.optimizer.HintPlanInfo;
  import com.alibaba.druid.sql.ast.SQLExpr;
  import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
  import com.alibaba.druid.sql.ast.statement.SQLSelect;
  import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
  
  import javax.annotation.Nullable;
  import java.util.List;
  import java.util.Map;
  
  public class ItemScalarSubQuery extends ItemSingleRowSubQuery {
      public ItemScalarSubQuery(String currentDb, SQLSelectQuery query, ProxyMetaManager metaManager, Map<String, String> usrVariables, int charsetIndex, @Nullable HintPlanInfo hintPlanInfo) {
          super(currentDb, query, false, metaManager, usrVariables, charsetIndex, hintPlanInfo);
          this.charsetIndex = charsetIndex;
          if (this.planNode.getColumnsSelected().size() > 1) {
              throw new MySQLOutPutException(ErrorCode.ER_OPERAND_COLUMNS, "", "Operand should contain 1 column(s)");
          }
          if (!this.correlatedSubQuery) {
              if ((this.planNode.getLimitFrom() == -1)) {
                  this.planNode.setLimitFrom(0);
                  this.planNode.setLimitTo(2);
              } else if (this.planNode.getLimitTo() > 2) {
                  this.planNode.setLimitTo(2);
              }
          }
      }
  
      @Override
      public SubSelectType subType() {
          return SubSelectType.SINGLEROW_SUBS;
      }
  
      @Override
      public void fixLengthAndDec() {
  
      }
  
      @Override
      public SQLExpr toExpression() {
          SQLSelect sqlSelect = new SQLSelect(query);
          return new SQLQueryExpr(sqlSelect);
      }
  
      @Override
      protected Item cloneStruct(boolean forCalculate, List<Item> calArgs, boolean isPushDown, List<Field> fieldList) {
          ItemScalarSubQuery cloneItem = new ItemScalarSubQuery(this.currentDb, this.query, this.metaManager, this.usrVariables, charsetIndex, this.hintPlanInfo);
          cloneItem.value = this.value;
          return cloneItem;
      }
  
  }
  