content: package com.alibaba.druid.bvt.sql.mysql.issues;
  
  import com.alibaba.druid.DbType;
  import com.alibaba.druid.sql.ast.SQLStatement;
  import com.alibaba.druid.sql.parser.SQLParserUtils;
  import com.alibaba.druid.sql.parser.SQLStatementParser;
  import org.junit.Test;
  
  import java.util.List;
  
  import static org.junit.Assert.assertEquals;
  
  /**
   * @author lizongbo
   * @see <a href="https://github.com/alibaba/druid/issues/5797">Issue来源</a>
   */
  public class Issue5797 {
      @Test
      public void test_parse_create_table() {
          for (DbType dbType : new DbType[]{
              DbType.mysql,
              DbType.postgresql,
              DbType.oracle,
              DbType.mariadb,
              DbType.sqlserver,
              DbType.h2,
              DbType.hive,
              //DbType.gaussdb,
              //DbType.oscar,
  //            DbType.db2,
  //            DbType.dm, DbType.kingbase,
  
          }) {
              for (String sql : new String[]{
                  "-- 给课程表增加类型字段\n"
                      + "alter table info_course drop column if exists course_type_id",
  
              }) {
                  System.out.println(dbType + "原始的sql===" + sql);
                  SQLStatementParser parser = SQLParserUtils.createSQLStatementParser(sql, dbType);
                  List<SQLStatement> statementList = parser.parseStatementList();
                  String sqlGen = statementList.toString();
                  System.out.println(dbType + "生成的sql===" + sqlGen);
                  StringBuilder sb = new StringBuilder();
                  for (SQLStatement statement : statementList) {
                      sb.append(statement.toString()).append(";");
                  }
                  sb.deleteCharAt(sb.length() - 1);
                  parser = SQLParserUtils.createSQLStatementParser(sb.toString(), dbType);
                  List<SQLStatement> statementListNew = parser.parseStatementList();
                  String sqlGenNew = statementList.toString();
                  System.out.println(dbType + "重新解析再生成的sql===" + sqlGenNew);
                  assertEquals(statementList.toString(), statementListNew.toString());
              }
          }
      }
  }
  