join

问题 I'm trying to do a left join in an EF query. I'm getting the following error: Error CS1941 The type of one of the expressions in the join clause is incorrect. Type inference failed in the call to 'GroupJoin' and here is the C# code: var foo = from m in db.ClientMasters join a in db.Orders on new { m.Id, Status = "N" } equals new { a.ClientID, a.Status } into a_join from a in a_join.DefaultIfEmpty() select new { m.ClientID, a.ID }; 回答1: I'm an idiot. The column names have to match in the join.

问题 After joining two dataframes (which have their own ID's) I have some duplicates (repeated ID's from both sources) I want to drop all rows that are duplicates on either ID (so not retain a single occurrence of a duplicate) I can group by the first ID, do a count and filter for count ==1, then repeat that for the second ID, then inner join these outputs back to the original joined dataframe - but this feels a bit long. Is there a simpler method like dropDuplicates() but where none of the

问题 After joining two dataframes (which have their own ID's) I have some duplicates (repeated ID's from both sources) I want to drop all rows that are duplicates on either ID (so not retain a single occurrence of a duplicate) I can group by the first ID, do a count and filter for count ==1, then repeat that for the second ID, then inner join these outputs back to the original joined dataframe - but this feels a bit long. Is there a simpler method like dropDuplicates() but where none of the

问题 I have a (heavily simplified) orders table, total being the dollar amount, containing: | id | client_id | type | total | |----|-----------|--------|-------| | 1 | 1 | sale | 100 | | 2 | 1 | refund | 100 | | 3 | 1 | refund | 100 | And clients table containing: | id | name | |----|------| | 1 | test | I am attempting to create a breakdown, by client, metrics about the total number of sales, refunds, sum of sales, sum of refunds etc. To do this, I am querying the clients table and joining the

问题 I have 2 tables, table Actions & table Users . Actions -> Users is many-one association. Table Actions (has thousands of rows) id uuid name type created_by org_id Table Users (has a max of hundred rows) id username org_id org_name I am trying to get the best join query to obtain a count with a WHERE clause. I need the count of distinct created_by s from table Actions with an org_name in Table Users that contains 'myorg'. Also, ( Actions.created_by = Users.username ) I currently have the below

问题 Trying to LEFT JOIN a table with partial string match. I've tried changing the wildcard in the LIKE condition, but it still only searches for the full string. Any suggestions? I've got a list of product abbreviations stored in a table. Would be easier to manage this list with partial matching versus having to spell out every product. Thanks in advance! CREATE TABLE `order` ( order_id INT (11) NOT NULL, shipping_firstname VARCHAR (128) NOT NULL, shipping_lastname VARCHAR (128) NOT NULL );

问题 Following my code: $list = $pdo->prepare("SELECT * FROM table_a INNER JOIN table_b ON table_a.id = table_b.blabla_id"); $list_result = $list->execute(); while($element = $list->fetch()) { //CONTENT } Now I would like to fetch the columns with something like echo $element['table_a.id']; - which doesn't work. I don't want to write an alias for every single column. Is there a way to deal with this? :) SOLUTION: $list = $pdo->prepare("SELECT * FROM table_a INNER JOIN table_b ON table_a.id = table

问题 I have table A with product_id,cost,year,quarter,... etc columns. I have another table B with product_id,base_cost,current_year,p_year,p_quarter,p_order columns. I want to write an update query to update A from B. My conditions are - WHERE A.product_id=B.product_id and A.year=B.current_year and (A.year=B.p_year and A.quarter>B.p_quarter) or A.year>B.p_year and A.cost=0; But the problem is, with these conditions if i have more than one rows in B then i only want to update from the row of B

问题 I have created a SP, but while compiling I am getting error as Error(9,1): PLS-00428: an INTO clause is expected in this SELECT statement Below is the SP CREATE OR REPLACE PROCEDURE FIP_VALID_TBL_TRANSMEDIA ( POUTMSG OUT VARCHAR2 ) AS BEGIN SELECT distinct TO_CHAR(sp.RJ_SPAN_ID) AS SPAN_ID, TO_CHAR(sp.RJ_MAINTENANCE_ZONE_CODE) AS MAINT_ZONE_CODE from APP_FTTX.span@SAT sp WHERE LENGTH(sp.RJ_SPAN_ID) = 21 AND (sp.RJ_SPAN_ID LIKE ('%SPN%') OR sp.RJ_SPAN_ID LIKE ('%SPQ%') OR sp.RJ_SPAN_ID LIKE ('

问题 I have created a SP, but while compiling I am getting error as Error(9,1): PLS-00428: an INTO clause is expected in this SELECT statement Below is the SP CREATE OR REPLACE PROCEDURE FIP_VALID_TBL_TRANSMEDIA ( POUTMSG OUT VARCHAR2 ) AS BEGIN SELECT distinct TO_CHAR(sp.RJ_SPAN_ID) AS SPAN_ID, TO_CHAR(sp.RJ_MAINTENANCE_ZONE_CODE) AS MAINT_ZONE_CODE from APP_FTTX.span@SAT sp WHERE LENGTH(sp.RJ_SPAN_ID) = 21 AND (sp.RJ_SPAN_ID LIKE ('%SPN%') OR sp.RJ_SPAN_ID LIKE ('%SPQ%') OR sp.RJ_SPAN_ID LIKE ('