content: /*
   * Copyright 1999-2018 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.sql.oracle.demo;
  
  import com.alibaba.druid.sql.SQLUtils;
  import com.alibaba.druid.sql.ast.SQLStatement;
  import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
  import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
  import com.alibaba.druid.util.JdbcConstants;
  import junit.framework.TestCase;
  
  import java.util.List;
  
  public class Demo_casewhen extends TestCase {
      public void test_demo_0() throws Exception {
          String sql = "select case when a = 20 then b else c end from emp";
  
          // parser得到AST
          List<SQLStatement> stmtList = SQLUtils.parseStatements(sql, JdbcConstants.ORACLE);
  
          SQLSelectStatement stmt = (SQLSelectStatement) stmtList.get(0);
  
          SQLCaseExpr caseExpr = (SQLCaseExpr) stmt.getSelect().getQueryBlock()
                  .getSelectList().get(0).getExpr();
          System.out.println(caseExpr.getItems());
      }
  }
  