使用sql查询mysql/oracle/sql server/gp数据库中指定表的字段信息(字段名/字段类型/字段长度/是否是主键/是否为空)
1,根据数据库类型拼接不同URL
/** * 根据类型不同拼接连接的URL * @param dbType 1：mysql、2：oracle、3：sql server、4：gp * @param ip * @param port * @param databaseName * @return*/ public static String getTestDbUrl(int dbType, String ip, String port, String databaseName){ String url = ""; if (Constant.DATABASE_TYPE_MYSQL == dbType){ //mysql url = "jdbc:mysql://"+ip+":"+port+"/"+databaseName+"?useUnicode=true&characterEncoding=UTF8"; }else if (Constant.DATABASE_TYPE_ORACLE == dbType){ //oracle url = "jdbc:oracle:thin:@"+ip+":"+port+":ORCL"; }else if (Constant.DATABASE_TYPE_SQL_SERVER == dbType){ //sql server url = "jdbc:sqlserver://"+ip+":"+port+";databaseName="+databaseName+";integratedSecurity=true"; }else if (Constant.DATABASE_TYPE_GP == dbType){ //gp url = "jdbc:postgresql://"+ip+":"+port+"/"+databaseName; } return url; }
2,创建连接并查询
/** * 通过jsbc获取数据 * @param driver driver * @param url 数据库url * @param username 用户名 * @param password 密码 * @param sql sql语句 * @param sqlType 语句类型 ，1：查询语句，2：创建语句 * @param columnConnt 查询语句返回列的个数 * @return List */ public static List<Map<String, String>> getJdbcData(String driver, String url, String username, String password, String sql, int sqlType, int columnConnt){ Connection con = null; Statement st = null; ResultSet rs = null; List<Map<String, String>> result = new ArrayList<>(); try { //1.加载oracle数据库驱动 Class.forName(driver); //2.获取数据库连接 con = DriverManager.getConnection(url, username, password); //3.获取执行sql语句的平台 st = con.createStatement(); //4.执行sql语句获取结果集 // 查询 if(sqlType == 1){ rs = st.executeQuery(sql); //5.循环获取结果集数据 int i = 1; while(rs.next()){ if(i <= columnConnt){ Map<String, String> resultMap = new HashMap<>(columnConnt); for (int j = 0; j < columnConnt; j++) { resultMap.put("column" + (j + 1) + "", rs.getString(j + 1)); } result.add(resultMap); } } }else{ // 创建 int rss = st.executeUpdate(sql); Map<String, String> resultMap = new HashMap<>(columnConnt); resultMap.put("column" + 1 + "", rss + ""); result.add(resultMap); } return result; } catch (ClassNotFoundException e) { e.printStackTrace(); Map<String, String> resultMap = new HashMap<>(columnConnt); resultMap.put("column1", "-1"); result.add(resultMap); } catch (SQLException e) { e.printStackTrace(); Map<String, String> resultMap = new HashMap<>(columnConnt); resultMap.put("column1", "-1"); result.add(resultMap); }finally{ //关闭rs if(rs != null){ try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } //关闭st if(st != null){ try { st.close(); } catch (SQLException e) { e.printStackTrace(); } } //关闭con if(con != null){ try { con.close(); } catch (SQLException e) { e.printStackTrace(); } } return result; } // return result; }
3,设置参数
/** * 查询指定数据库中指定表的字段信息 * @param databaseType 数据库类型: 1：mysql、2：oracle、3：sql server、4：gp * @param databaseName 数据库名称 * @param databaseIp 数据库ip * @param databasePort 数据库端口 * @param databaseUserName 数据库用户名 * @param databaseUserPassword 数据库用户的密码 * @param tableName 表名 * @return*/ public static List<Map<String, String>> getColumnInfoByTableName(int databaseType, String databaseName, String databaseIp, String databasePort, String databaseUserName, String databaseUserPassword, String tableName){ String sql = ""; if (Constant.DATABASE_TYPE_MYSQL == databaseType){ //mysql sql = "SELECT column_name, data_type,(case when data_type = 'int' or data_type = 'float' or data_type = 'double' or data_type = 'decimal' then NUMERIC_PRECISION else CHARACTER_MAXIMUM_LENGTH end ) as data_length,\n" + "(case when IS_NULLABLE = 'NO' then 0 else 1 end)as data_Null,(case when COLUMN_KEY='PRI' then 1 else 0 end) as data_IsPK\n" + " FROM information_schema.COLUMNS WHERE table_schema = '"+databaseName+"' and table_name = '"+tableName+"'"; }else if (Constant.DATABASE_TYPE_ORACLE == databaseType){ //oracle sql = "SELECT column_name, data_type, data_length, NULLABLE,(case when column_name=(select col.column_name \n" + "from user_constraints con, user_cons_columns col \n" + "where con.constraint_name = col.constraint_name \n" + "and con.constraint_type='P' \n" + "and col.table_name = "+tableName+"\n" + ") then 1 else 0 end) as IsPK\n" + " FROM all_tab_cols\n" + " WHERE table_name = '"+tableName+"' "; }else if (Constant.DATABASE_TYPE_SQL_SERVER == databaseType){ //sql server sql = "SELECT C.name as column_name, T.name as data_type, COLUMNPROPERTY(C.id,C.name,'PRECISION') as data_length, \n" + "convert(bit,case when exists(SELECT 1 FROM sysobjects where xtype='PK' and parent_obj=c.id and name in (\n" + " SELECT name FROM sysindexes WHERE indid in(\n" + " SELECT indid FROM sysindexkeys WHERE id = c.id AND colid=c.colid))) then 1 else 0 end) \n" + " as data_IsPK, convert(bit,C.IsNullable) as data_Null\n" + "FROM syscolumns C INNER JOIN systypes T ON C.xusertype = T.xusertype \n" + "inner join sysobjects d on a.id=d.id and d.xtype='U' and d.name<>'dtproperties' \n" + "where T.name is not null\n" + "and d.name='"+tableName+"'"; }else if (Constant.DATABASE_TYPE_GP == databaseType){ //gp } List<Map<String, String>> columnNameList = JdbcUtil.getJdbcData(SingletonHoldResource.getInstance().getDictMap(Constant.DB_DRIVER).get(Integer.toString(databaseType)), getTestDbUrl(databaseType, databaseIp, databasePort, databaseName), databaseUserName, databaseUserPassword, sql, 1, 5); //结果中的对应关系:column1 -- name; column2 -- type; column3 -- length; column4 -- IsNull; column5 -- isPk; return columnNameList; }
