5. 数据排序（ORDER BY子句） SELECT * FROM table_name ORDER BY column1 [ASC|DESC]; ORDER BY子句用于对查询结果进行排序。例如 SELECT * FROM products ORDER BY price ASC; ，会将 products 表中的产品按照价格升序排列，价格低的产品排在前面；而 SELECT *
mysql>show create table evaluate_result \G ***1.row*** Table: evaluate_result CreateTable:CREATE TABLE `evaluate_result`( `sys_no` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '内部主键', `wh_no` varchar(32) NOT NULL DEFAULT '' COMMENT'仓库编码', `business_no` varchar(20) NOT NULL ...
SQL SELECT Query - Learn how to use the SQL SELECT statement to retrieve data from a database efficiently. Explore examples and syntax for effective data management.
The fully qualified name for a table is [Server/Instance].[DatabaseName].[Schema].[TableName]. So if we really wanted to be explicit we could use something like SELECT LastName FROM [KAWLAPTOP\SQLEXPRESS2014].[AdventureWorks2012].[Person].[Person] to do a query. Luckily we typically wri...
SELECT*FROMPerson.AddressWHERECity ='SEATTLE'ANDPostalCode =98104OPTION(RECOMPILE,USEHINT ('ASSUME_MIN_SELECTIVITY_FOR_FILTER_ESTIMATES','DISABLE_PARAMETER_SNIFFING')); GO M. 使用 QUERYTRACEON 提示 以下示例使用QUERYTRACEON查询提示。 该示例使用AdventureWorks2022数据库。 可以使用以下查询为特定查询启用跟...
drop table t; create table t as select * from dba_objects; -- 设置显示参数 set linesize 1000 set pagesize 2000 set autotrace off ALTER SESSION SET statistics_level = all; 低效分页写法:全表扫描的陷阱 语句1:外层过滤的分页查询 select * from (select t.*, rownum as rn from t) a where...
SELECT some_fieldFROM ? 不能使用占位符代替查询的字段名称,下面的查询可以成功绑定参数,但只是作为一个常量,而不是字段的名称。 SELECT ? asmy_field FROM table 不能使用占位符绑定逗号分隔的多个列表项值;如果你绑定 “1,2,3″ 给下面的查询语句,将得到意外的结果。
Table1.Items - Too big AS [Quantity], "Too Big" AS [Reason] FROM Table1 UNION ALL SELECT Table1.Season ID AS Season ID, Table1.Items - Too small AS [Quantity] "Too Small" AS [Reason] FROM Table1 查询结果在数据网格中如下所示: 有关转置选项的详细信息,请参见对数据进行转置(从列到...
String sql = "SELECT id,name FROM test_table"; Statement stmt = conn.createStatement(); ResultSet resultSet = stmt.executeQuery(sql); while (resultSet.next()) { String id = resultSet.getString("id"); String name = resultSet.getString("name"); System.out.println(id); System.out.prin...
derived_table 從資料庫中擷取資料列的子查詢。 derived_table可用來作為外部查詢的輸入。 derived_table 可以使用 Transact-SQL 資料表值建構函式功能來指定多個資料列。 例如: SELECT * FROM (VALUES (1, 2), (3, 4), (5, 6), (7, 8), (9, 10) ) AS MyTable(a, b);。 如需詳細資訊,請參閱...