content: /*
   * Copyright 1999-2017 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.druid.support.opds.udf;
  
  import com.alibaba.druid.DbType;
  import com.alibaba.druid.sql.SQLUtils;
  import com.alibaba.druid.sql.ast.SQLStatement;
  import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
  import com.alibaba.druid.stat.TableStat;
  import com.alibaba.druid.stat.TableStat.Column;
  import com.alibaba.druid.stat.TableStat.Condition;
  import com.alibaba.druid.support.json.JSONUtils;
  import com.aliyun.odps.udf.UDF;
  
  import java.util.ArrayList;
  import java.util.List;
  
  public class ExportConditions extends UDF {
      public String evaluate(String sql) {
          return evaluate(sql, null);
      }
  
      public String evaluate(String sql, String dbType) {
          return evaluate(sql, dbType, null);
      }
  
      public String evaluate(String sql, String dbTypeName, Boolean compactValues) {
          DbType dbType = dbTypeName == null ? null : DbType.valueOf(dbTypeName);
          try {
              List<SQLStatement> statementList = SQLUtils.parseStatements(sql, dbType);
              SchemaStatVisitor visitor = SQLUtils.createSchemaStatVisitor(dbType);
  
              for (SQLStatement stmt : statementList) {
                  stmt.accept(visitor);
              }
  
              List<List<Object>> rows = new ArrayList<List<Object>>();
              List<Condition> conditions = visitor.getConditions();
              for (int i = 0; i < conditions.size(); ++i) {
                  TableStat.Condition condition = conditions.get(i);
                  Column column = condition.getColumn();
                  String operator = condition.getOperator();
                  List<Object> values = condition.getValues();
  
                  List<Object> row = new ArrayList<Object>();
                  row.add(column.getTable());
                  row.add(column.getName());
                  row.add(operator);
                  if (values.isEmpty()) {
                      row.add(null);
                  } else if (values.size() == 1) {
                      if (compactValues != null && compactValues.booleanValue()) {
                          row.add(values);
                      } else {
                          row.add(values.get(0));
                      }
                  } else {
                      row.add(values);
                  }
                  rows.add(row);
              }
  
              return JSONUtils.toJSONString(rows);
          } catch (Exception ex) {
              System.err.println("error sql : " + sql);
              ex.printStackTrace();
              return null;
          }
      }
  }
  