content: package org.jeecg.common.util.dynamic.db;
  
  import org.apache.commons.lang3.StringUtils;
  import org.jeecg.common.constant.DataBaseConstant;
  import org.jeecg.common.system.vo.DynamicDataSourceModel;
  
  import java.text.MessageFormat;
  import java.util.Map;
  
  /**
   * 根据不同的数据库，动态生成SQL，例如分页
   */
  public class SqlUtils {
  
      public static final String DATABSE_TYPE_MYSQL = "mysql";
      public static final String DATABSE_TYPE_POSTGRE = "postgresql";
      public static final String DATABSE_TYPE_ORACLE = "oracle";
      public static final String DATABSE_TYPE_SQLSERVER = "sqlserver";
  
  
      /**
       * 分页SQL
       */
      public static final String MYSQL_SQL = "select * from ( {0}) sel_tab00 limit {1},{2}";
      public static final String POSTGRE_SQL = "select * from ( {0}) sel_tab00 limit {2} offset {1}";
      public static final String ORACLE_SQL = "select * from (select row_.*,rownum rownum_ from ({0}) row_ where rownum <= {1}) where rownum_>{2}";
      public static final String SQLSERVER_SQL = "select * from ( select row_number() over(order by tempColumn) tempRowNumber, * from (select top {1} tempColumn = 0, {0}) t ) tt where tempRowNumber > {2}";
  
      /**
       * 获取所有表的SQL
       */
      public static final String MYSQL_ALLTABLES_SQL = "select distinct table_name from information_schema.columns where table_schema = {0}";
      public static final String POSTGRE__ALLTABLES_SQL = "SELECT distinct c.relname AS  table_name FROM pg_class c";
      public static final String ORACLE__ALLTABLES_SQL = "select distinct colstable.table_name as  table_name from user_tab_cols colstable";
      public static final String SQLSERVER__ALLTABLES_SQL = "select distinct c.name as  table_name from sys.objects c";
  
      /**
       * 获取指定表的所有列名
       */
      public static final String MYSQL_ALLCOLUMNS_SQL = "select column_name from information_schema.columns where table_name = {0} and table_schema = {1}";
      public static final String POSTGRE_ALLCOLUMNS_SQL = "select table_name from information_schema.columns where table_name = {0}";
      public static final String ORACLE_ALLCOLUMNS_SQL = "select column_name from all_tab_columns where table_name ={0}";
      public static final String SQLSERVER_ALLCOLUMNS_SQL = "select name from syscolumns where id={0}";
  
      /*
       * 判断数据库类型
       */
  
      public static boolean dbTypeIsMySQL(String dbType) {
          return dbTypeIf(dbType, DATABSE_TYPE_MYSQL, DataBaseConstant.DB_TYPE_MYSQL_NUM);
      }
  
      public static boolean dbTypeIsOracle(String dbType) {
          return dbTypeIf(dbType, DATABSE_TYPE_ORACLE, DataBaseConstant.DB_TYPE_ORACLE_NUM);
      }
  
      public static boolean dbTypeIsSQLServer(String dbType) {
          return dbTypeIf(dbType, DATABSE_TYPE_SQLSERVER, DataBaseConstant.DB_TYPE_SQLSERVER_NUM);
      }
  
      public static boolean dbTypeIsPostgre(String dbType) {
          return dbTypeIf(dbType, DATABSE_TYPE_POSTGRE, DataBaseConstant.DB_TYPE_POSTGRESQL_NUM);
      }
  
      /**
       * 判断数据库类型
       */
      public static boolean dbTypeIf(String dbType, String... correctTypes) {
          for (String type : correctTypes) {
              if (type.equalsIgnoreCase(dbType)) {
                  return true;
              }
          }
          return false;
      }
  
      /**
       * 获取全 SQL
       * 拼接 where 条件
       *
       * @param sql
       * @param params
       * @return
       */
      public static String getFullSql(String sql, Map params) {
          return getFullSql(sql, params, null, null);
      }
  
      /**
       * 获取全 SQL
       * 拼接 where 条件
       * 拼接 order 排序
       *
       * @param sql
       * @param params
       * @param orderColumn 排序字段
       * @param orderBy     排序方式，只能是 DESC 或 ASC
       * @return
       */
      public static String getFullSql(String sql, Map params, String orderColumn, String orderBy) {
          StringBuilder sqlBuilder = new StringBuilder();
          sqlBuilder.append("SELECT t.* FROM ( ").append(sql).append(" ) t ");
          if (params != null && params.size() >= 1) {
              sqlBuilder.append("WHERE 1=1 ");
              for (Object key : params.keySet()) {
                  String value = String.valueOf(params.get(key));
                  if (StringUtils.isNotBlank(value)) {
                      sqlBuilder.append(" AND (").append(key).append(" = N'").append(value).append("')");
                  }
              }
              if (StringUtils.isNotBlank(orderColumn) && StringUtils.isNotBlank(orderBy)) {
                  sqlBuilder.append("ORDER BY ").append(orderColumn).append(" ").append("DESC".equalsIgnoreCase(orderBy) ? "DESC" : "ASC");
              }
          }
          return sqlBuilder.toString();
      }
  
      /**
       * 获取求数量 SQL
       *
       * @param sql
       * @return
       */
      public static String getCountSql(String sql) {
          return String.format("SELECT COUNT(1) \"total\" FROM ( %s ) temp_count", sql);
      }
  
      /**
       * 生成分页查询 SQL
       *
       * @param dbType 数据库类型
       * @param sql
       * @param page
       * @param rows
       * @return
       */
      public static String createPageSqlByDBType(String dbType, String sql, int page, int rows) {
          int beginNum = (page - 1) * rows;
          Object[] sqlParam = new Object[3];
          sqlParam[0] = sql;
          sqlParam[1] = String.valueOf(beginNum);
          sqlParam[2] = String.valueOf(rows);
          if (dbTypeIsMySQL(dbType)) {
              sql = MessageFormat.format(MYSQL_SQL, sqlParam);
          } else if (dbTypeIsPostgre(dbType)) {
              sql = MessageFormat.format(POSTGRE_SQL, sqlParam);
          } else {
              int beginIndex = (page - 1) * rows;
              int endIndex = beginIndex + rows;
              sqlParam[2] = Integer.toString(beginIndex);
              sqlParam[1] = Integer.toString(endIndex);
              if (dbTypeIsOracle(dbType)) {
                  sql = MessageFormat.format(ORACLE_SQL, sqlParam);
              } else if (dbTypeIsSQLServer(dbType)) {
                  sqlParam[0] = sql.substring(getAfterSelectInsertPoint(sql));
                  sql = MessageFormat.format(SQLSERVER_SQL, sqlParam);
              }
          }
          return sql;
      }
  
      /**
       * 生成分页查询 SQL
       *
       * @param sql
       * @param page
       * @param rows
       * @return
       */
      public static String createPageSqlByDBKey(String dbKey, String sql, int page, int rows) {
          DynamicDataSourceModel dynamicSourceEntity = DataSourceCachePool.getCacheDynamicDataSourceModel(dbKey);
          String dbType = dynamicSourceEntity.getDbType();
          return createPageSqlByDBType(dbType, sql, page, rows);
      }
  
      private static int getAfterSelectInsertPoint(String sql) {
          int selectIndex = sql.toLowerCase().indexOf("select");
          int selectDistinctIndex = sql.toLowerCase().indexOf("select distinct");
          return selectIndex + (selectDistinctIndex == selectIndex ? 15 : 6);
      }
  
      public static String getAllTableSql(String dbType, Object... params) {
          if (StringUtils.isNotEmpty(dbType)) {
              if (dbTypeIsMySQL(dbType)) {
                  return MessageFormat.format(MYSQL_ALLTABLES_SQL, params);
              } else if (dbTypeIsOracle(dbType)) {
                  return ORACLE__ALLTABLES_SQL;
              } else if (dbTypeIsPostgre(dbType)) {
                  return POSTGRE__ALLTABLES_SQL;
              } else if (dbTypeIsSQLServer(dbType)) {
                  return SQLSERVER__ALLTABLES_SQL;
              }
          }
          return null;
      }
  
      public static String getAllColumnSQL(String dbType, Object... params) {
          if (StringUtils.isNotEmpty(dbType)) {
              if (dbTypeIsMySQL(dbType)) {
                  return MessageFormat.format(MYSQL_ALLCOLUMNS_SQL, params);
              } else if (dbTypeIsOracle(dbType)) {
                  return MessageFormat.format(ORACLE_ALLCOLUMNS_SQL, params);
              } else if (dbTypeIsPostgre(dbType)) {
                  return MessageFormat.format(POSTGRE_ALLCOLUMNS_SQL, params);
              } else if (dbTypeIsSQLServer(dbType)) {
                  return MessageFormat.format(SQLSERVER_ALLCOLUMNS_SQL, params);
              }
          }
          return null;
      }
  
  }
  