db2 subquery

The WITH clause is the content of the SQL-99 standard and is introduced in Oracle9.2. The WITH clause can be used to name subqueries. When a subquery is used in multiple places, you can directly use the query name. Subqueries named by this clause are treated as inline views or temporary tables by the optimizer. In the latter case, query efficiency can be improved.Using the SCOTT mode, you can use the inline view for each employee to obtain the number

The nested SELECT statement is also called a subquery, for example, select name from BBC where region = (select region from BBC where name = 'Brazil ') the query result of one SELECT statement can be used as the input value of another statement. The preceding SQL statement is used to obtain all countries in the same region as 'Brazil '(Brazil. Subqueries can appear not only in the WHERE clause, but also in the from clause. They can be used as a tempor

subqueries, multiple table queries, federated queriesThese three concepts are interpreted slightly differently in different versions of SQL, roughly as follows: Join connectionCan look at the relevant SQL information, or buy a book of SQL 1, such as: SELECT * from TAB1 where ID in (SELECT id form tab2 where ...)The query sentence in parentheses above belongs to "subquery". 2, select tab1.*, tab2.* from Tab1, tab2 where TAB1. [Field]=tab2. FieldThis

This example describes the MySQL subquery usage. Share to everyone for your reference, specific as follows: Suppose the table my_tbl contains three field a,b,c; now you need to query the number of records for which column B is the minimum for each different value of column A in the table. For example, the table record is: A b C1 3 ' CD '2 3 ' nHD '1 5 ' BG '2 6 ' CDs '1 7 ' Kiy '3 7 ' VSD '3 8 ' NDF ' Expect the results to be: A b C1 3 ' CD '2 3

Org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile (querytranslatorimpl.java:136)At Org.hibernate.engine.query.spi.HQLQueryPlan. (hqlqueryplan.java:105) at Org.hibernate.engine.query.spi.HQLQueryPlan. (hqlqueryplan.java:80) at Org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan (queryplancache.java:168) At Org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan (abstractsessionimpl.java:221) at Org.hibernate.int Ernal. Abstractsessionimpl.createquery (abstractse

mapply.mid = Mconfig.mid WHERE Mapply.aid In ( SELECT Aid From ' mapply ' where state = $state ORDER BY ' atime ', ' uid ' DESC ) So no error, MO away thought OK, but after running found that the data have problems and simply read out the content of the application form is not the same, only to find limit position misplaced, and then put limit in, the results of the following error This version of the MySQL doesn ' t yet support ' LIMIT in/all/any/some

(select Top 5 code from Renyuan)Select top 5*from Renyuan where code not in (select Top ten code from Renyuan) --a total of a few pagesSelect CEILING (COUNT (*)/5.0) from Renyuan --Find out all information about people older than 35 years in the sales department SELECT * from Renyuan where code in(select code from Renyuan where age>35 and ygbm=(select Bmcode from bumen where bmname= ' sales Department ')) --View all personnel information and replace the department number with the department nam

1 GROUP by indicates a sort, followed by the first data in each group, where the condition is indicated, if you need conditional filtering on the order, you should follow the property name with a + condition. and cannot use where2 aggregate function sum () count () Avg () max () min () group by is a group of queries that divide the same class of criteria into a set of general group by that is used in conjunction with an aggregate function. For exampleA person who has a score of more than 80 poin

Tags: io ar sp on C R SQL BS as1. Check all subdirectories by root directoryWith Locs (Menu_id,menu_name_ch,parent_menu_id,loclevel)As(SELECT a.menu_id,a.menu_name_ch,a.parent_menu_id,0 as Loclevel from Sys_menu_info Awhere a.menu_id=75UNION AllSELECT a.menu_id,a.menu_name_ch,a.parent_menu_id,loclevel+1 from Sys_menu_info AINNER JOIN locs p on a.parent_menu_id=p.menu_id)SELECT * from Locs2. Start querying by sub-directoryWith Locs (Menu_id,menu_name_ch,parent_menu_id,loclevel)As(SELECT a.menu_id

Label:--Paging data----row_number () is called window-opening function, can be paged operation Select Row_number () over (order by ID) as Num,*from gb_data----adds a sequential num value to each column to facilitate the use of the first few data. Select row_number () over (order by ID) as num,* from Gb_data where Num>5and num 10--This line of code is wrong, because the system does not recognize how much num is, why? -Because of the order of execution, the SQL statement executes the from, then

Renyuan--second pageSelect Top 5 * from Renyuan where code not in (select Top 5 code from Renyuan)--Page ThreeSelect Top 5 * from Renyuan where code not in (select top of code from Renyuan)--a total of several pages????Select CEILING (COUNT (*)/5.0) from Renyuan--Find out all information about people older than 35 years in the sales departmentSELECT * from Renyuan where code in(select code from Renyuan where age>35 and bc=(select Bcode from bumen where bname= ' sales Department '))--View all pe

I. Defining what a subquery is When a query is a condition of another query, it is called a subqueryYou can add a subquery anywhere in the SQL. two. When to use subqueries Use it when the problem cannot be solved in one step. For example: query whose salary is higher than SCOTT's high select ename from the emp where sal > (select sal from emp where ename = ' SCOTT '); 10 Questions that are noted by a

Basic knowledge1, associated subqueries and unrelated subqueries In a unassociated subquery, an internal query executes only once and returns its value to an external query, and the external query uses the value returned to it by the internal query in its processing. In the associated subquery, the internal query is executed once for each row of data returned by the external query. In addition, the informa

of values. Therefore, you can sum each record (UseSumFunction), but the current record and previous recordPriceAnd, as shown in the following figure.SQLStatement: Select A. XH, A. Price,( Select Sum (Price) From T_product B Where B. XH A. XH) As Totalprice From T_product from the preceding SQL statement, A subquery is used to calculate the value of totalprice field, the basic principle is to XH value (. XH ) to calculate the

Tag: Use Ar data 2014 sp c time new ef I. Application of subquery 1. Paging Query1) 5 data entries are displayed on each page; 2) Top 5 pages (3-1) -- 3rd Select top 5 * from car where code not in -- Skip ...... Obtain the first few data records.(Select top 10 code from car -- number of intermediate values skipped) -- Query data on a specified page2. Retrieve the total number of pagesSelect ceiling (count (*)/5.0) from car PS: Count (*) is an integer

The subquery is not supported in hiveThis does not imply that it does not support in or notIn or not in the back is fixed value words are supportedBut it can be customized.For exampleSelect ID from table not in (all-in-a-But this is not supported.Select ID from table1 not in (Select ID from table2 where col1 = ' a ')We need to use the left join to implement(1) Connect the Table1 and table2 to the eligible dataSelect T1.id as id1,t2.id as Id2 from tabl

For example, update table1 t1 set t1.name= (Select t2.name from table2 t2 where t2.age = 20) Cause of error: the subquery contains more than one record. If you want to update data in batches, You can nest the data, for example, the following SQL statement. Of course, you can continue nesting. Update table1 t1 set t1.name=(Select t3.name, t3.id from(Select t2.name from table2 t2 where t2.age = 20)T3 where t3.id = t1.id) Next to"=The returned result

I went to an interview with two cool Internet companies a few days ago and encountered problems in SQL. Well, unfortunately, let's take a look at it. Score 1. Use group Group by Dimension For example: Calculate the total score of each student. SELECT student, SUM (score) FROM score group by student Average score for each student SELECT student, AVG (score) FROM score group by student You can also follow the class and Course 2. Differences between having and where Having is similar to where. It

The value of the query condition comes from another query. For example, sqlserver SQL: Select * from products where categoryid = (select top 1 categoryid from categories where categoryname = 'produce ') The implementation code of this SQL statement is as follows: DbSession.Default.From Compare the SQL statements generated by the component Text: SELECT * FROM [Products] WHERE [Products].[CategoryID] = ( SELECT TOP 1 [Categories].[CategoryID] FROM [Categories] WHERE [Categories].[CategoryName] = @

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->Create table tb1 (id int identity (1, 1), name varchar (10), remark varchar (50) default ''); Create table tb2 (xid int identity (1, 1), name varchar (10 )); Insert into tb1 (name)Select 'A'Union all select 'B'Union all select 'C'Insert into tb2 (name) select 'x' Select * from tb1 where id in (select id from tb2)Select * from tb1 where id in (select xid from tb2) Drop table tb1Drop table tb2; The r