qlikview left join

Tags: SQL statementsProject requirements change, before writing a query SQL, need to modify, nausea for a long while did not change well, finally want to go, spell to spell (splicing SQL), the original directly to the inner join changed to the left join on OK.After writing that feeling Ah! Really for the fountainhead come ah, what the best programming habit is to

Four sheets contract, customer, Customer3, Customer4: This is a more familiar 3-sheet connectionSELECT *From Test.contract AJOIN Test.customer b on a.num = b.num2JOIN test.customer3 C on a.num = C.NUM3; The connection is not necessarily followed by a join to the first table.SELECT *From Test.contract AJOIN Test.customer b on a.num = b.num2Left JOIN test.customer4 D on b.num2 = d.num4;SELECT *From Test.con

Tags: happy sharing feature for me select information from where BSPToday's work learning path is a database of small knowledge, at that time did not distinguish the why, hereby recorded share a sudden. As we all know, the tables of the database are all separate, but when we do a union query (multi-table query), we get the value returned by the database as if it were in a table, because the database generates a temporary table to return to the data information we want when we make a federated qu

Label:There are currently two tables, Sgroup and Sgroupuser, which are associated by Gkey, while the Sgroup table records the group, and the Sgroupuser record is the user in the group, so there is no data in the Sgroupuser. You need to use the left join to get the data: The LINQ syntax is as follows: var sg = ( from the dc.sgroup in dc.sgroupuser on G.gkey equals Gu.gkey into L

Filter the condition and then establish the index of the related query field in the table in the same time. So it's pretty fast in the case of Big Data multi-table federated queries.SELECTM.*, SS. Sensorcode,ss. Sensorstatus,ss. Manufacturerid,ss. Electricity,ss. Voltage,ss. Minelectricity,ss. Minvoltage,ss. Temperature,ss. Statusupdtedate,ss. UpdateStatus, TP. Pricingstrategyid,tps. Freeduration,bat. Berthtypeid from(SELECTT.*, BS. Parkstatus,bs. Changetime, CA. Cantonname, SE. SectionName from

key name, without specifying the result field (that is, all mappings). By default, when a table is searched, the foreign key table is not queried, and the database query is not read until it is actually used, and if Include () is used, the specified foreign key table information is read when the table is read.Overload mode:Located in namespace System.Data.Entity.Infrastructurepublic dbqueryIt can be written like this:EF has generated the database mapping model classes for album and genre as wel

There are contests (contest_id, hacker_id, name), colleges (college_id, contest_id), Challenges (challenge_id, college_id), View_ Stats (challenge_id, total_views, Total_unique_views), Submission_stats (challenge_id, Total_submissions, Total_ accepted_submissions) Table Output Required: 1, contest_id, hacker_id, name, Total_submissions and, Total_accepted_submissions and, Total_views and 2, contest_id Ascending Sql: Select con.contest_id, con.hacker_id, Con.name, sum (t2.sumtotalsubmissions), su

exists is faster than not.difference between in and =Select name from student where name in (' Zhang ', ' Wang ', ' Li ', ' Zhao ');Select name from student where Name= ' Zhang ' or name= ' li ' orName= ' Wang ' or name= ' Zhao 'The result is the same.Left\right join is an external connection, inner join is an inner joinThe external connection has the main table and from the table, the main table is

Assume that the table structure is: user_info table: role_info table: to query some data from the user_info table and role_info table, for example, when logging on to the system, in addition to the login name and password, you can also query additional information, such as user permissions, which may be connected. Here we use the left join: the SQL statement is as follows: selectu. *, r. role_name, r. right

First, the concept: – Find all the records of the table on the left side of the leave join. The system will first use Table A and table B to make a Cartesian product, and then take table A as the base table, the table a part of the Cartesian product is null records. The final form of your results. – When a left connection is made, it involves the primary table, t

NULL NULL NULLB524. Fully connected1 Select * fromT1 Full outer JoinT2 onT1. B=t2.b2 3 A b C B E4 ---------- ---------- ---- ---------- ----5A1 B15B136A1 B26B277A2 B38B3Ten8A2 B38B329A2 B4 A NULL NULLTen NULL NULL NULLB525. Cross connection (Cartesian product)1 Select * fromT1 Cross JoinT22 3 A b C B E4 ---------- ---------- ---- ---------- ----5A1 B15B136A1 B15B277A1 B15B3Ten8A1 B15B329A1 B15B52TenA1 B26B13 OneA1 B26B27 AA1 B26B3Ten -A1 B26B32 -A1 B26B52 theA2 B3

Suppose the table's structure is: User_info table: Role_info table: To query some data from table user_info and table role_info, such as when you log on to the system, In addition to querying for information in terms of login names and passwords, additional information, such as user permissions, may be used to connect. Here use LEFT JOIN to connect: The SQL statement is as follows: Select u.*,r.r

Entity class User, Dept. Each user has a dept attribute on the -----------------------------------------------------------Model Class-------------------------------------------------------- ------------------ public class User implements Serializable { /** * Serialization ID ID * / private static final long Serialversionuid = 1L; Private Integer ID; User name private String userName; Password private String password; Private Dept Dept;

Label:Oracle outer JOIN (OUTER join) Left OUTER join (the table on the left is unrestricted) Right outer join (the table on the right is unrestricted) All-out connection (both the

Oracle outer JOIN (OUTER join) Left OUTER join (the table on the left is unrestricted) Right outer join (the table on the right is unrestricted) All-out connection (both the l